To explore the effects of farming methods,straw returning and their interaction on corn yield and nitrogen utilization,the experiment was conducted for two consecutive years from 2016 to 2017 at the Xiangyang Experime...To explore the effects of farming methods,straw returning and their interaction on corn yield and nitrogen utilization,the experiment was conducted for two consecutive years from 2016 to 2017 at the Xiangyang Experimental Base of Northeast Agricultural University in Heilongjiang Province of China.The method of combining farming with straw returning was used and six treatments as rotary tillage(R)+no straw returning(K),rotary tillage(R)+straw returning(S),tillage(T)+no straw returning(K),tillage(T)+straw returning(S),tillage(T)+subsoiling(D)+no straw returning(K)and tillage(T)+subsoiling(D)+straw returning(S)were set to study the effects of different tillage methods and straw returning on corn yield and nitrogen accumulation and utilization.The corn yield,nitrogen accumulation,nitrogen transport,grain weight and dry matter accumulation of tillage(T)+subsoiling(D)and tillage(T)were significantly higher than those of rotary tillage(R)treatment.Meanwhile,the corn yield,nitrogen accumulation and dry matter accumulation of TD treatment were significantly higher than those of T treatment;the corn yield,dry matter accumulation,kernel weight,nitrogen dry matter production efficiency and nitrogen grain production efficiency of S treatment were significantly higher than those of K treatment.Among the treatments,the yield,nitrogen accumulation and utilization efficiency of TDS,TS and TDK were the highest.The yield,nitrogen accumulation and nitrogen transport of TDS were significantly higher than those of TS.In 2016,TDS production increased by 7.30%and 8.20%compared with TS;and TDS nitrogen accumulation increased by 6.78%and 9.50%compared with TS,while the yield and nitrogen grain production efficiency were significantly higher than those of TDK.Therefore,under the conditions of this experiment,on the basis of straw returning,tillage+subsoiling was the suitable farming method.展开更多
The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw retur...The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.展开更多
Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cott...Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cotton(Gossypium hirsutum L.)cropping system remains uncertain.The objective of this study was to quantify the long-term(10 years)impact of carbon(C)input on SOC sequestration,soil aggregation and crop yields in a wheat-cotton cropping system in the Yangtze River Valley,China.Five treatments were arranged with a single-factor randomized design as follows:no straw return(Control),return of wheat straw only(Wt),return of cotton straw only(Ct),return of 50%wheat and 50%cotton straw(Wh-Ch)and return of 100%wheat and 100%cotton straw(Wt-Ct).In comparison to the Control,the SOC content increased by 8.4 to 20.2%under straw return.A significant linear positive correlation between SOC sequestration and C input(1.42-7.19 Mg ha^(−1)yr^(−1))(P<0.05)was detected.The percentages of aggregates of sizes>2 and 1-2 mm at the 0-20 cm soil depth were also significantly elevated under straw return,with the greatest increase of the aggregate stability in the Wt-Ct treatment(28.1%).The average wheat yields increased by 12.4-36.0%and cotton yields increased by 29.4-73.7%,and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.The average sustainable yield index(SYI)reached a maximum value of 0.69 when the C input was 7.08 Mg ha^(−1)yr^(−1),which was close to the maximum value(SYI of 0.69,C input of 7.19 Mg ha^(−1)yr^(-1))in the Wt-Ct treatment.Overall,the return of both wheat and cotton straw was the best strategy for improving SOC sequestration,soil aggregation,yields and their sustainability in the wheat-cotton rotation system.展开更多
Straw returning into field is a direct and effective measure to reduce the straw burning and improve the soil organic matter content.Straw returning directly to field needs higher performance machines,especially under...Straw returning into field is a direct and effective measure to reduce the straw burning and improve the soil organic matter content.Straw returning directly to field needs higher performance machines,especially under the condition of large amount of straw in the field is more difficult.Therefore,the model of conservation tillage by combination of subsoiling and straw returning was studied.Experiments on combined tillage machine for effect of subsoiling on working quality and total power consumption for high stubble straw returning were carried out.The high stubble rape field was used as the test field;forward speed and PTO speed of tractor were taken as the test factors.Straw coverage rate and straw proportion of the lower half burying layer were taken as the test indexes of the working quality.Subsoiling and rotary burying(SRB)returning operation was used as experimental group and direct rotary burying(DRB)returning operation was the control group.The results showed that under different working conditions,the mean value of straw coverage rate of SRB was 93.0%,straw proportion of the lower half burying layer was 52.8%,these values were better than DRB.The straw proportion of the lower half burying layer of SRB compared with DRB increased by 10.5%.Two factors all had a significant effect on it under the SRB and DRB conditions.Subsoiling could significantly reduce the PTO torque.Under low speed,the total power consumption of SRB was slightly smaller,while under high speed,the total power consumption of DRB was slightly smaller.Under the SRB and DRB conditions,two factors both had a significant effect on total power consumption.The optimal working combination(working quality as the primary index)was 1.5 km/h of forward speed and 720 r/min of PTO speed.Under this condition,the straw coverage rate was 94.1%,the straw proportion of the lower half burying layer was 59.0%,and the total power consumption was 35.62 kW.The research confirmed that subsoiling is beneficial to the working quality and total power consumption of high stubble straw returning machine.It could meet the working requirements,and provide a reference for optimizing straw returning machine and improving working quality.展开更多
[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Aca...[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Academy of Agricultural Sciences as the experimental base,the effects of returning double-crop wheat and corn straw to field(Twm),returning single-crop corn straw to field(Tm),returning single-crop wheat straw to field(Tw)on soil temperature,water content,straw decomposition rate and nutrient release,soil organic matter and bulk density were studied systematically.[Results]Twm treatment could effectively alleviate the effects of meteorological conditions on soil temperature and water content.The decomposition rate of straw treated with Twm was 4.7%higher than that of Tm treatment,3.8%higher than that of Tw treatment,10.5%higher than that of Tm treatment,and the decomposition rate of straw showed a trend of"first fast,then slow and then fast".The release of nitrogen from straw was basically similar to that of straw decay,and the release of potassium and phosphorus increased at first and then remained basically unchanged.The release rate of potassium was the highest,followed by phosphorus and nitrogen.The content of soil organic matter in Twm treatment increased by 11.67%annually,an annual average of 0.998 g/kg.The soil bulk density of Twm treatment decreased by 0.058 g/cm^(3) annually,an annual average of 4.29%.The fundamental reason is that Twm treatment provides conditions(temperature,water content,nutrition)for microbial growth,reproduction,enzyme production and biochemical reaction,and increases the exchange capacity of soil and external water,heat,gas and fertilizer.[Conclusions]It is expected is to help people change their understanding of returning straw to field from"quick harvest"to"fertilizer transformation".展开更多
[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wh...[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wheat stem rot and yield were studied by observation and experiments.[Results]The incidence rate and disease index of stem rot and white head rate of wheat were significantly reduced and the yield was significantly increased by adopting the method of straw returning to the field with the separation of"returning and seeding".The incidence rate and disease index of stem rot and white head rate of wheat were higher than those of the CK and the yield was significantly reduced when adopting the straw returning method of direct sowing.Treatment T_(1)(after maize was harvested,fertilizers,a nutrient-loaded microbial agent and a soil conditioner were evenly spread on the surface of straw,which was then returned to the field using a straw returning machine twice,and then ploughing,soil preparation and wheat sowing were carried out)showed an incidence rate of wheat crown rot 54.8%lower than that of the CK and a white head rate 87.5%lower than that of the CK,and the yield was 2305 kg/hm^(2) higher than that of the CK.[Conclusions]Straw returning can increase soil organic matter content,reduce soil bulk density,enhance soil respiration,and improve wheat disease resistance and yield.展开更多
Tillage practices and organic amendment are strategies used worldwide to preserve the properties and fertility of soils.This study aimed to elucidate effects of 3-year field treatments of tillage practice and straw ma...Tillage practices and organic amendment are strategies used worldwide to preserve the properties and fertility of soils.This study aimed to elucidate effects of 3-year field treatments of tillage practice and straw management on physical properties of Mollisols,root architecture and maize yield in northeast China.The experiment was conducted from 2015 to 2018 following a splitplot design of a randomized complete block with tillage practices[rotary tillage(R)and deep tillage(D)]as main plots and straw managements[straw returning(S),straw returning and organic fertilizer(M),straw removal(T)]as subplots.Soil samples at 0-15,15-30,30-50 cm depths and root samples at the seedling stage were collected.The results showed that DM treatment significantly improved soil moisture content at 10-50 cm soil depth and decreased soil compaction(P<0.05),which led to a better root architecture.Rotary tillage had a slower thermal conductivity but better thermal insulation performance,while deep tillage showed a higher daily temperature difference.Bulk density of topsoil was significantly lower in DS(1.16 g·cm^(-3))than in other treatments,but the soil permeability in DS(1.40 mm·min^(-1)in 0-15 soil depth and 1.45 mm·min-1in 15-30 cm soil depth)was the highest.At the maize seedling stage,DM had the highest root dry weight,root-shoot ratio and root length,while RM had the highest root volume,root furcation number and root tip number.The maize yield of three years in DM was 6.19%,5.21%and 15.72%higher than that in DS,DT and RM(P<0.01),respectively.Relative to RT and DT,a slight decrease(2.72%and 0.93%,respectively)in maize yield under RS and DS was observed,which could be alleviated by the addition of organic fertilizer.The correlation matrix indicated that kernel per ear number and 100-kernel weight were the dominant factors that affected maize yield.Redundancy analysis suggested that straw managements and tillage practices were significantly positively correlated with root-shoot ratio,root dry weight,maximum root length,the total root length and maize yield,but significantly negatively correlated with soil compaction,bulk density,soil moisture content and soil temperature.Among all the treatments,deep tillage with straw returning and the addition of organic fertilizer was recommended as a promising strategy in restoring soil productivity,promoting maize growth and increasing maize yield in Mollisols of northeast China and similar regions around the world.展开更多
Long-term straw return is an important carbon source for improving soil organic carbon(SOC) stocks in croplands, and straw removal through burning is also a common practice in open fields in South China. However, the ...Long-term straw return is an important carbon source for improving soil organic carbon(SOC) stocks in croplands, and straw removal through burning is also a common practice in open fields in South China. However, the specific effects of long-term rice straw management on SOC fractions, the related enzyme activities and their relationships, and whether these effects differ between crop growing seasons remain unknown. Three treatments with equal nitrogen, phosphorus, and potassium nutrient inputs, including straw/ash and chemical nutrients, were established to compare the effects of straw removal(CK), straw return(SR), and straw burned return(SBR). Compared to CK, long-term SR tended to improve the yield of early season rice(P=0.057), and significantly increased total organic carbon(TOC) and microbial biomass carbon(MBC) in double-cropped rice paddies. While SBR had no effect on TOC, it decreased light fraction organic carbon(LFOC) in early rice and easily oxidizable organic carbon(EOC) in late rice, significantly increased dissolved organic carbon(DOC), and significantly decreased soil p H. These results showed that MBC was the most sensitive indicator for assessing changes of SOC in the double-cropped rice system due to long-term straw return. In addition, the different effects on SOC fraction sizes between SR and SBR were attributed to the divergent trends in most of the soil enzyme activities in the early and late rice that mainly altered DOC, while DOC was positively affected by β-xylosidase in both early and late rice. We concluded that straw return was superior to straw burned return for improving SOC fractions, but the negative effects on soil enzyme activities in late rice require further research.展开更多
To assess the effects of straw return coupled with deep nitrogen(N)fertilization on grain yield and N use efficiency(NUE)in mechanical pot-seedling transplanting(MPST)rice,the seedlings of two rice cultivars,i.e.,Yuxi...To assess the effects of straw return coupled with deep nitrogen(N)fertilization on grain yield and N use efficiency(NUE)in mechanical pot-seedling transplanting(MPST)rice,the seedlings of two rice cultivars,i.e.,Yuxiangyouzhan and Wufengyou 615 transplanted by MPST were applied with N fertilizer at 150 kg/hm2 and straw return at 6 t/hm2 in early seasons of 2019 and 2020.The experiment comprised of following treatments:CK(no fertilizer and no straw return),MDS(deep N fertilization and straw return),MBS(broadcasting fertilizer and straw return),MD(deep N fertilization without straw return),MB(broadcasting fertilizer without straw return).Results depicted that the MDS treatment significantly increased the rice yield by 41.69%-72.22%due to total above-ground biomass,leaf area index and photosynthesis increased by 54.70%-55.80%,38.52%-52.17%and 17.89%-28.40%,respectively,compared to the MB treatment.In addition,the MDS treatment enhanced the total N accumulation by 37.74%-43.69%,N recovery efficiency by 141.45%-164.65%,N agronomic efficiency by 121.76%-134.19%,nitrate reductase by 46.46%-60.86%and glutamine synthetase by 23.56%-31.02%,compared to the MB treatment.The average grain yield and NUE in both years for Yuxiangyouzhan were higher in the MDS treatment than in the MD treatment.Hence,deep N fertilization combined with straw return can be an innovative technique with improved grain yield and NUE in MPST in South China.展开更多
Straw return is an effective way to improve crop grain yield and potassium(K)use efficiency by increasing soil K content.However,the effects of straw return on soil K supplying capacity,replacement of K fertilizer,and...Straw return is an effective way to improve crop grain yield and potassium(K)use efficiency by increasing soil K content.However,the effects of straw return on soil K supplying capacity,replacement of K fertilizer,and K-use efficiency under maize(Zea mays L.)–rice(Oryza sativa L.)cropping systems are little studied.A two-year field experiment was conducted to determine the physiological determinants of K-use efficiency under straw return with four K fertilization rates.Sr33(straw returned plus 33%of K fertilizer applied)and Sr67(straw returned plus 67%of K fertilizer applied)increased annual crop yields by 1.5%and 3.2%and increased agronomic K-use efficiency by respectively 2.9 and 1.3-fold on average in the two years,compared with the conventional practice S0K100(no straw returned plus normal amounts of K fertilizer applied).The Sr33 and Sr67 treatments resulted in significantly greater equilibrium K concentration ratios(CR0 K)and specifically exchangeable K(KX)values according to quantity/intensity(Q/I)relationship analyses,indicating improvement of the potential soil K supply capacity.However,the Sr67 better maintained the soil exchangeable K level and K balance.The results suggested that K released from maize and rice straw can replace about half of chemical K fertilizer,depending on the available K content in maize–rice cropping system production.展开更多
Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA...Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA).Moreover,the labile SOC fractions play an important role in OC turnover and sequestration.The aims of this study were to determine how different corn straw returning modes affect the contents of labile SOC fractions and OC associated with WSA.Corn straw was returned in the following depths:(1)on undisturbed soil surface(NTS),(2)in the 0–10 cm soil depth(MTS),(3)in the 0–20 cm soil depth(CTS),and(4)no corn straw applied(CK).After five years(2014–2018),soil was sampled in the 0–20 and 20–40 cm depths to measure the water-extractable organic C(WEOC),permanganate oxidizable C(KMnO4-C),light fraction organic C(LFOC),and WSA fractions.The results showed that compared with CK,corn straw amended soils(NTS,MTS and CTS)increased SOC content by 11.55%–16.58%,WEOC by 41.38%–51.42%,KMnO4-C and LFOC by 29.84%–34.09%and 56.68%–65.36%in the 0–40 cm soil depth.The LFOC and KMnO4-C were proved to be the most sensitive fractions to different corn straw returning modes.Compared with CK,soils amended with corn straw increased mean weight diameter by 24.24%–40.48%in the 0–20 cm soil depth.The NTS and MTS preserved more than 60.00%of OC in macro-aggregates compared with CK.No significant difference was found in corn yield across all corn straw returning modes throughout the study period,indicating that adoption of NTS and MTS would increase SOC content and improve soil structure,and would not decline crop production.展开更多
Straw incorporation is a widespread practice to promote agricultural sustainability.However,the potential effects of straw incorporation with the prolonged time on nitrogen(N)runoff loss from paddy fields are not well...Straw incorporation is a widespread practice to promote agricultural sustainability.However,the potential effects of straw incorporation with the prolonged time on nitrogen(N)runoff loss from paddy fields are not well studied.The current study addresses the knowledge gap by assessing the effects of straw incorporation on the processes influencing N runoff patterns and its impacts on crop yield,N uptake,total N(TN),and soil organic matter(SOM).We conducted field experiments with rice(Oryza sativa L.)–wheat(Triticum aestivum L.)rotation,rice–tobacco(Nicotiana tabacum L.)rotation,and double-rice cropping in subtropical China from 2008 to 2012.Each rotation had three N treatments:zero N fertilization(CK),chemical N fertilization(CF),and chemical N fertilization combined with straw incorporation(CFS).The treatment effects were assessed on TN runoff loss,crop yield,N uptake,soil TN stock,and SOM.Results showed that TN runoff was reduced by substituting part of the chemical N fertilizer with straw N in the double rice rotation,while crop N uptake was significantly(P<0.05)decreased due to the lower bioavailability of straw N.In contrast,in both rice–wheat and rice–tobacco rotations,TN runoff in CFS was increased by 0.9–20.2%in the short term when straw N was applied in addition to chemical N,compared to CF.However,TN runoff was reduced by 2.3–19.3%after three years of straw incorporation,suggesting the long-term benefits of straw incorporation on TN loss reduction.Meanwhile,crop N uptake was increased by 0.8–37.3%in the CFS of both rotations.This study demonstrates the challenges in reducing N runoff loss while improving soil fertility by straw incorporation over the short term but highlights the potential of long-term straw incorporation to reduce N loss and improve soil productivity.展开更多
To understand the long-term effects of combined organic and chemical nitrogen fertilization on soil organic C(SOC) and total N(TN), we conducted a 30-year field experiment with a wheat–maize rotation system on the Hu...To understand the long-term effects of combined organic and chemical nitrogen fertilization on soil organic C(SOC) and total N(TN), we conducted a 30-year field experiment with a wheat–maize rotation system on the Huang-HuaiHai Plain during 1990–2019. The experimental treatments consisted of five fertilizer regimes: no fertilizer(control), chemical fertilizer only(NPK), chemical fertilizer with straw(NPKS), chemical fertilizer with manure(NPKM), and 1.5 times the rate of NPKM(1.5NPKM). The NPK, NPKS, and NPKM treatments had equal N inputs. The crop yields were measured over the whole experimental duration. Soil samples were collected from the topsoil(0–10 and 10–20 cm) and subsoil(20–40 cm) layers for assessing soil aggregates and taking SOC and TN measurements. Compared with the NPK treatment, the SOC and TN contents increased significantly in both the topsoil(24.1–44.4% for SOC and 22.8–47.7% for TN) and subsoil layers(22.0–47.9% for SOC and 19.8–41.8% for TN) for the organically amended treatments(NPKS, NPKM and 1.5NPKM) after 30 years, while no significant differences were found for the average annual crop yields over the 30 years of the experiment. The 0–10 cm layer of the NPKS treatment and the 20–40 cm layer of the NPKM treatment had significantly higher macroaggregate fraction mass proportions(19.8 and 27.0%) than the NPK treatment. However, the 0–10 and 20–40 cm layers of the 1.5NPKM treatment had significantly lower macroaggregate fraction mass proportions(–19.2 and –29.1%) than the control. The analysis showed that the higher SOC and TN in the soil of organically amended treatments compared to the NPK treatment were related to the increases in SOC and TN protected in the stable fractions(i.e., free microaggregates and microaggregates within macroaggregates), in which the contributions of the stable fractions were 81.1–91.7% of the increase in SOC and 83.3–94.0% of the increase in TN, respectively. The relationships between average C inputs and both stable SOC and TN stocks were significantly positive with R2 values of 0.74 and 0.72(P<0.01) for the whole 40 cm soil profile, which indicates the importance of N for soil C storage. The results of our study provide key evidence that long-term combined organic and chemical nitrogen fertilization, while maintaining reasonable total N inputs, benefited soil C and N storage in both the topsoil and subsoil layers.展开更多
Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current dev...Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current developments in biochar industry and the production practices prevalent among enterprises in China are critiques.This review analyzes current knowledge gaps,challenges,and opportunities in the industrial application of straw biochar returning.Biochar standards,the quantitative and qualitative analysis methods for biochar,and high-value-added products that are based on biochar are critically examined with goal of providing recommendations for future studies.We propose production and modification of biochar that is application oriented to enhance its fitness for purpose as well as long-term and large-space-scale field study to better understand its impact on soil properties and ecotoxicology.Finally,we make prospects for the future development of SBR,including constructing a standard system about straw biochar returning and promoting self-discipline of biochar industry and the establishment of a biochar-based agricultural production model.展开更多
Greenhouse vegetable cultivation(GVC)is an example of intensive agriculture aiming to increase crop yields by extending cultivation seasons and intensifying agricultural input.Compared with cropland,studies on the eff...Greenhouse vegetable cultivation(GVC)is an example of intensive agriculture aiming to increase crop yields by extending cultivation seasons and intensifying agricultural input.Compared with cropland,studies on the effects of farming management regimes on soil microorganisms of the GVC system are rare,and our knowledge is limited.In the present study,we assessed the impacts of different long-term fertilization regimes on soil fungal community structure changes in a greenhouse that has been applied in tomato(Solanum lycopersicum L.)cultivation for 11 consecutive years.Results showed that,when taking the non-fertilizer treatment of CK as a benchmark,both treatments of Conventional chemical N(CN)and Organic amendment only(MNS)significantly decreased the fungal richness by 16%–17%,while the Conventional chemical N and straw management(CNS)restored soil biodiversity at the same level.Saprotroph and pathotroph were the major trophic modes,and the abundance of the pathotroph fungi in treatment of CNS was significantly lower than those in CK and CN soils.The CNS treatment has significantly altered the fungal composition of the consecutive cropping soils by reducing the pathogens,e.g.,Trichothecium and Lecanicillium,and enriching the plant-beneficial,e.g.,Schizothecium.The CNS treatment is of crucial importance for sustainable development of the GVC system.展开更多
As a common practice in agricultural system,straw return has been reported to release a large number of trace gases and attractedmuch attention.However,the role of straw return in toluene emission remains poorly under...As a common practice in agricultural system,straw return has been reported to release a large number of trace gases and attractedmuch attention.However,the role of straw return in toluene emission remains poorly understood.In this study we measured the emissions of toluene as well as other 50 volatile organic compounds(VOCs)from wheat straw return for 66 days under flooded and non-flooded conditions,respectively.The results showed that substantial toluene was released from the returned wheat straw particularly under flooded condition,and primarily derived from the secondary product.Toluene emissions from the returned wheat straw were 36.8 and 8.45 mg C/kg,sharing 28.0%and 8.6%of total VOCs released,and over 90% of toluene emissions occurred between days 24-56 and 0-17 under flooded and non-flooded conditions,respectively.The emission rates of toluene were relatively high but decreased sharply at the beginning 2 days,and then was steady until 24 days under the two moisture conditions.After the initial decrease these rose again to form one“peak emission window”between days 24-56 under flooded condition,while these were still very low and steady until the end under non-flooded condition.The toluene emission rates significantly positively correlated with microbial biomass C under flooded condition,but negatively associated with bacteria and fungus number,microbial biomass C,and CO_(2) flux under non-flooded condition,suggesting that microorganism might play an important role in toluene emissions from wheat straw return.A rough estimate indicated that straw return might be important for biogenic toluene.展开更多
Recently,returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution.Meanwhile,the slow decomposition of straw may harm the growth of the next...Recently,returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution.Meanwhile,the slow decomposition of straw may harm the growth of the next crop.This study aimed to determine the effects of rumen microorganisms(RMs)on straw decomposition,bacterial microbial community structure,soil properties,and soil enzyme activity.The results showed that RMs significantly enhanced the degradation rate of straw in the soil,reaching 39.52%,which was 41.37%higher than that of the control on the 30th day after straw return.After 30 d,straw degradation showed a significant slower trend in both the control and the experimental groups.According to the soil physicochemical parameters,the application of rumen fluid expedited soil matter transformation and nutrient buildup,and increased the urease,sucrase,and cellulase activity by 10%‒20%.The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid.The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability,which was the main reason for the accelerated straw decomposition.Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw,proposing a viable solution to the problem of sluggish straw decomposition.展开更多
Returning rice straw and leguminous green manure alone or in combination to soil is effective in improving soil fertility in South China.Despite the popularity of this practice,our understanding o f the underlying pro...Returning rice straw and leguminous green manure alone or in combination to soil is effective in improving soil fertility in South China.Despite the popularity of this practice,our understanding o f the underlying processes for straw and manure combined application is relatively poor.In this study,rice straw(carbon(C)/nitrogen(N)ratio of 63),green manure(hairy vetch,C/N ratio of 14),and their mixtures(C/N ratio of 25 and 35)were added into a paddy soil,and their effects on soil N availability and C or N loss under waterlogged conditions were evaluated in a 100-d incubation experiment.All plant residue treatments significantly enhanced C〇2 and CH4 emissions,but decreased N2O emission.Dissolved organic C(DOC)and N(DON)and microbial biomass C in soil and water-soluble organic C and N and mineral N in the upper aqueous layer above soil were also enhanced by all the plant residue treatments except the rice straw treatment,and soil microbial biomass N and mineral N were lower in the rice straw treatment than in the other treatments.Changes in plant residue C/N ratio,DOC/DON ratio,and cellulose content significantly affected greenhouse gas emissions and active C and N concentrations in soil.Additionally,the treatment with green manure alone yielded the largest C and N losses,and incorporation of the plant residue mixture with a C/N ratio of 35 caused the largest net global warming potential(nGWP)among the amended treatments.In conclusion,the co-incorporation of rice straw and green manure can alleviate the limitation resulting from only applying rice straw(N immobilization)or the sole application of leguminous green manure(high C and N losses),and the residue mixture with a C/N ratio of 25 is a better option because of lower nGWP.展开更多
Crop straw is an important natural resource in China because it is rich in nutrients.When returned to fields after harvests,the straw can improve soil quality and the next crop’s yield.Evaluating the economic values ...Crop straw is an important natural resource in China because it is rich in nutrients.When returned to fields after harvests,the straw can improve soil quality and the next crop’s yield.Evaluating the economic values of the main ecological services of a farmland ecosystem while implementing the straw return technique can be a more systematic and comprehensive approach to better understand the contribution of straw return to the development of ecological agriculture.Based on the data of a field experiment established in 2010 with varying numbers of years of straw return,four ecological services,i.e.,agricultural product and industrial raw materials,atmospheric regulation and purification,soil nutrient accumulation,and water conservation,were selected to estimate a net ecosystem service value(ESV)of a wheat field’s ecosystem services.Agro-ecosystem service appraisal theories were applied to estimate the economic value of each service.Results showed that straw returning improved the total ESV in the wheat system.Compared to the no straw return treatment,1 year,3 years,5 years or 7 years of straw returning altered the economic value of the agricultural product and industrial raw materials(EVAIM)by-5.93%to 7.84%and improved atmospheric regulation(EVAR)by 13.66%-30.80%,soil nutrient accumulation(EVSNA)by 59.87%-233.31%and water conservation(EVWC)by 2.60%-13.26%.The total ESV of wheat plots with 1-7 years of straw returning was 3.67%-27.41%higher than that with no straw return,and the total ESV increased with the increase in years of straw return.The proportion of EVAIM out of the total ESV in this wheat field system was highest(accounted for 47.09%-55.64%),followed by EVAR and EVWC.The value of EVSNA was the lowest.However,the proportion of EVSNA was higher than that of water conservation after the fifth year of straw return.In general,the adoption of continuous straw returning in a wheat field ecosystem is ecologically valuable.The results can inform the development and implementation of ecological compensation policies involving straw return.展开更多
Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon(Si)pool in paddy,which is crucial for the healthy growth of rice.However,owing to little knowledge about soil mi...Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon(Si)pool in paddy,which is crucial for the healthy growth of rice.However,owing to little knowledge about soil microbial communities responsible for straw degradation,how straw return affects Si bioavailability,its uptake,and rice yield remains elusive.Herein,we investigate the change of soil Si fractions and microbial community in a 39-year-old paddy field amended by a long-term straw return.Results show that rice straw return significantly increased soil bioavailable Si and rice yield from 29.9%to 61.6%and from 14.5%to 23.6%,respectively,when compared to NPK fertilization alone.Straw return significantly altered soil microbial community abundance.Acidobacteria was positively and significantly related to amorphous Si,while Rokubacteria at phylum level,Deltaproteobacteria,and Holophagae at class level was negatively and significantly related to organic matter adsorbed and Fe/Mn-oxide-combined Si in soils.Redundancy analysis of their correlations further demonstrated that Si status significantly explained 12%of soil bacterial community variation.These findings suggest that soil bacteria community and diversity interact with Si mobility by altering its transformation,thus resulting in the balance of various nutrient sources to drive biological Si cycle in agroecosystem.展开更多
基金Supported by the Special Fund for Agro-scientific Research in Public Interest in China(201503119-06-01)。
文摘To explore the effects of farming methods,straw returning and their interaction on corn yield and nitrogen utilization,the experiment was conducted for two consecutive years from 2016 to 2017 at the Xiangyang Experimental Base of Northeast Agricultural University in Heilongjiang Province of China.The method of combining farming with straw returning was used and six treatments as rotary tillage(R)+no straw returning(K),rotary tillage(R)+straw returning(S),tillage(T)+no straw returning(K),tillage(T)+straw returning(S),tillage(T)+subsoiling(D)+no straw returning(K)and tillage(T)+subsoiling(D)+straw returning(S)were set to study the effects of different tillage methods and straw returning on corn yield and nitrogen accumulation and utilization.The corn yield,nitrogen accumulation,nitrogen transport,grain weight and dry matter accumulation of tillage(T)+subsoiling(D)and tillage(T)were significantly higher than those of rotary tillage(R)treatment.Meanwhile,the corn yield,nitrogen accumulation and dry matter accumulation of TD treatment were significantly higher than those of T treatment;the corn yield,dry matter accumulation,kernel weight,nitrogen dry matter production efficiency and nitrogen grain production efficiency of S treatment were significantly higher than those of K treatment.Among the treatments,the yield,nitrogen accumulation and utilization efficiency of TDS,TS and TDK were the highest.The yield,nitrogen accumulation and nitrogen transport of TDS were significantly higher than those of TS.In 2016,TDS production increased by 7.30%and 8.20%compared with TS;and TDS nitrogen accumulation increased by 6.78%and 9.50%compared with TS,while the yield and nitrogen grain production efficiency were significantly higher than those of TDK.Therefore,under the conditions of this experiment,on the basis of straw returning,tillage+subsoiling was the suitable farming method.
基金Supported by the National Key Research and Development Plan Project(2016YFD0300909-04)。
文摘The effects of different amounts of carbon and nitrogen sources on the soil microbial biomass carbon,dissolved organic carbon and related enzyme activities were studied by the simulation experiment of rice straw returning to the field,and the mechanism of the decomposition of rice straw returning to the field was discussed.Completely randomized experiment of the two factors of the three levels was designed,and a total of nine treatments of indoor soil incubation tests were conducted.Full amount of rice straw was applied to the soil in this simulation experiment and different amounts of brown sugar and urea were added in the three levels of 0(no carbon source and nitrogen source),1(low levels of carbon and nitrogen sources)and 2(high levels of carbon and nitrogen sources),respectively.The results showed that the addition of different amounts of carbon and nitrogen sources to the rice straw could increase the soil carbon content.Compared with T0N0,the microbial biomass carbon of T2N2 was increased significantly by 170.48%;the dissolved organic carbon content of T1N2 was significantly increased by 58.14%and the free humic acid carbon contents of T0N2,T1N1 and T2N0 were significantly increased by 56.16%and 45.55%and 47.80%,respectively;however,there were no significant differences among those of treatments at later incubation periods.The addition of different carbon and nitrogen sources could promote the soil enzyme activities.During the incubation period,all of the soil enzyme activities of adding sugar and urea were higher than those of T0N0 treatment.Therefore,the addition of different amounts of carbon and nitrogen sources to rice straw returning could improve soil microbial biomass carbon content,dissolved organic carbon and soil enzyme activities.
基金supported by the National Natural Science Foundation of China(32071968)the Jiangsu Agricultural Science and Technology Innovation Fund,China(CX(22)2015))the Jiangsu Collaborative Innovation Center for Modern Crop Production,China。
文摘Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cotton(Gossypium hirsutum L.)cropping system remains uncertain.The objective of this study was to quantify the long-term(10 years)impact of carbon(C)input on SOC sequestration,soil aggregation and crop yields in a wheat-cotton cropping system in the Yangtze River Valley,China.Five treatments were arranged with a single-factor randomized design as follows:no straw return(Control),return of wheat straw only(Wt),return of cotton straw only(Ct),return of 50%wheat and 50%cotton straw(Wh-Ch)and return of 100%wheat and 100%cotton straw(Wt-Ct).In comparison to the Control,the SOC content increased by 8.4 to 20.2%under straw return.A significant linear positive correlation between SOC sequestration and C input(1.42-7.19 Mg ha^(−1)yr^(−1))(P<0.05)was detected.The percentages of aggregates of sizes>2 and 1-2 mm at the 0-20 cm soil depth were also significantly elevated under straw return,with the greatest increase of the aggregate stability in the Wt-Ct treatment(28.1%).The average wheat yields increased by 12.4-36.0%and cotton yields increased by 29.4-73.7%,and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.The average sustainable yield index(SYI)reached a maximum value of 0.69 when the C input was 7.08 Mg ha^(−1)yr^(−1),which was close to the maximum value(SYI of 0.69,C input of 7.19 Mg ha^(−1)yr^(-1))in the Wt-Ct treatment.Overall,the return of both wheat and cotton straw was the best strategy for improving SOC sequestration,soil aggregation,yields and their sustainability in the wheat-cotton rotation system.
基金The authors acknowledge that this work was supported by the Special Fund for Agro-scientific Research in the Public Interest(No.201503136)the National Key Technology R&D Program(No.2017YFD0301300).
文摘Straw returning into field is a direct and effective measure to reduce the straw burning and improve the soil organic matter content.Straw returning directly to field needs higher performance machines,especially under the condition of large amount of straw in the field is more difficult.Therefore,the model of conservation tillage by combination of subsoiling and straw returning was studied.Experiments on combined tillage machine for effect of subsoiling on working quality and total power consumption for high stubble straw returning were carried out.The high stubble rape field was used as the test field;forward speed and PTO speed of tractor were taken as the test factors.Straw coverage rate and straw proportion of the lower half burying layer were taken as the test indexes of the working quality.Subsoiling and rotary burying(SRB)returning operation was used as experimental group and direct rotary burying(DRB)returning operation was the control group.The results showed that under different working conditions,the mean value of straw coverage rate of SRB was 93.0%,straw proportion of the lower half burying layer was 52.8%,these values were better than DRB.The straw proportion of the lower half burying layer of SRB compared with DRB increased by 10.5%.Two factors all had a significant effect on it under the SRB and DRB conditions.Subsoiling could significantly reduce the PTO torque.Under low speed,the total power consumption of SRB was slightly smaller,while under high speed,the total power consumption of DRB was slightly smaller.Under the SRB and DRB conditions,two factors both had a significant effect on total power consumption.The optimal working combination(working quality as the primary index)was 1.5 km/h of forward speed and 720 r/min of PTO speed.Under this condition,the straw coverage rate was 94.1%,the straw proportion of the lower half burying layer was 59.0%,and the total power consumption was 35.62 kW.The research confirmed that subsoiling is beneficial to the working quality and total power consumption of high stubble straw returning machine.It could meet the working requirements,and provide a reference for optimizing straw returning machine and improving working quality.
基金Shaanxi Provincial Innovation Capability Support Program(2019XY-03)Key R&D Program of Shaanxi Province(2019ZDLN01-05-02)+2 种基金Guangxi Key R&D Program(GuiKe AB19259016)Project of Shaanxi Academy of Forestry Sciences(SXLK2020-0218)Xi'an Science and Technology Plan Project(20193051YF039NS039,20NYYF0026).
文摘[Objectives]To alleviate the influence of meteorological conditions on soil environment(temperature and water content)and maintain high and stable grain yield.[Methods]Taking Sunzhen Experimental Station of Weinan Academy of Agricultural Sciences as the experimental base,the effects of returning double-crop wheat and corn straw to field(Twm),returning single-crop corn straw to field(Tm),returning single-crop wheat straw to field(Tw)on soil temperature,water content,straw decomposition rate and nutrient release,soil organic matter and bulk density were studied systematically.[Results]Twm treatment could effectively alleviate the effects of meteorological conditions on soil temperature and water content.The decomposition rate of straw treated with Twm was 4.7%higher than that of Tm treatment,3.8%higher than that of Tw treatment,10.5%higher than that of Tm treatment,and the decomposition rate of straw showed a trend of"first fast,then slow and then fast".The release of nitrogen from straw was basically similar to that of straw decay,and the release of potassium and phosphorus increased at first and then remained basically unchanged.The release rate of potassium was the highest,followed by phosphorus and nitrogen.The content of soil organic matter in Twm treatment increased by 11.67%annually,an annual average of 0.998 g/kg.The soil bulk density of Twm treatment decreased by 0.058 g/cm^(3) annually,an annual average of 4.29%.The fundamental reason is that Twm treatment provides conditions(temperature,water content,nutrition)for microbial growth,reproduction,enzyme production and biochemical reaction,and increases the exchange capacity of soil and external water,heat,gas and fertilizer.[Conclusions]It is expected is to help people change their understanding of returning straw to field from"quick harvest"to"fertilizer transformation".
基金Supported by Shaanxi Provincial Innovation Capability Support Program(2019XY-03)Shaanxi Provincial Key R&D Program(2019ZDLNY01-05-02)+3 种基金Key R&D Project of Guangxi Zhuang Autonomous Region(GK AB19259016)Scientific and Technological Innovation Program of Shaanxi Academy of Forestry(SXLK2020-0218)Xi’an Science and Technology Program(20193051YF039N039)Xianyang Key R&D Program(2021DYF-GY-0008)。
文摘[Objectives]This study was conducted to improve the quality of straw returning to the field,enhance wheat disease resistance and ensure high and stable yield of wheat.[Methods]The effects of four returning modes on wheat stem rot and yield were studied by observation and experiments.[Results]The incidence rate and disease index of stem rot and white head rate of wheat were significantly reduced and the yield was significantly increased by adopting the method of straw returning to the field with the separation of"returning and seeding".The incidence rate and disease index of stem rot and white head rate of wheat were higher than those of the CK and the yield was significantly reduced when adopting the straw returning method of direct sowing.Treatment T_(1)(after maize was harvested,fertilizers,a nutrient-loaded microbial agent and a soil conditioner were evenly spread on the surface of straw,which was then returned to the field using a straw returning machine twice,and then ploughing,soil preparation and wheat sowing were carried out)showed an incidence rate of wheat crown rot 54.8%lower than that of the CK and a white head rate 87.5%lower than that of the CK,and the yield was 2305 kg/hm^(2) higher than that of the CK.[Conclusions]Straw returning can increase soil organic matter content,reduce soil bulk density,enhance soil respiration,and improve wheat disease resistance and yield.
基金the National Key Research and Developmental Program of China(2017YFD0300502-2)。
文摘Tillage practices and organic amendment are strategies used worldwide to preserve the properties and fertility of soils.This study aimed to elucidate effects of 3-year field treatments of tillage practice and straw management on physical properties of Mollisols,root architecture and maize yield in northeast China.The experiment was conducted from 2015 to 2018 following a splitplot design of a randomized complete block with tillage practices[rotary tillage(R)and deep tillage(D)]as main plots and straw managements[straw returning(S),straw returning and organic fertilizer(M),straw removal(T)]as subplots.Soil samples at 0-15,15-30,30-50 cm depths and root samples at the seedling stage were collected.The results showed that DM treatment significantly improved soil moisture content at 10-50 cm soil depth and decreased soil compaction(P<0.05),which led to a better root architecture.Rotary tillage had a slower thermal conductivity but better thermal insulation performance,while deep tillage showed a higher daily temperature difference.Bulk density of topsoil was significantly lower in DS(1.16 g·cm^(-3))than in other treatments,but the soil permeability in DS(1.40 mm·min^(-1)in 0-15 soil depth and 1.45 mm·min-1in 15-30 cm soil depth)was the highest.At the maize seedling stage,DM had the highest root dry weight,root-shoot ratio and root length,while RM had the highest root volume,root furcation number and root tip number.The maize yield of three years in DM was 6.19%,5.21%and 15.72%higher than that in DS,DT and RM(P<0.01),respectively.Relative to RT and DT,a slight decrease(2.72%and 0.93%,respectively)in maize yield under RS and DS was observed,which could be alleviated by the addition of organic fertilizer.The correlation matrix indicated that kernel per ear number and 100-kernel weight were the dominant factors that affected maize yield.Redundancy analysis suggested that straw managements and tillage practices were significantly positively correlated with root-shoot ratio,root dry weight,maximum root length,the total root length and maize yield,but significantly negatively correlated with soil compaction,bulk density,soil moisture content and soil temperature.Among all the treatments,deep tillage with straw returning and the addition of organic fertilizer was recommended as a promising strategy in restoring soil productivity,promoting maize growth and increasing maize yield in Mollisols of northeast China and similar regions around the world.
基金supported by the National Key Research and Development Program of China (2017YFD0301601)the China Postdoctoral Science Foundation (2016M600512)+1 种基金the Open Project Program of State Key Laboratory of Rice Biology, Ministry of Science and Technology, China (20190401)the Jiangxi Province Postdoctoral Research Project Preferential Grant, China (2017KY16)。
文摘Long-term straw return is an important carbon source for improving soil organic carbon(SOC) stocks in croplands, and straw removal through burning is also a common practice in open fields in South China. However, the specific effects of long-term rice straw management on SOC fractions, the related enzyme activities and their relationships, and whether these effects differ between crop growing seasons remain unknown. Three treatments with equal nitrogen, phosphorus, and potassium nutrient inputs, including straw/ash and chemical nutrients, were established to compare the effects of straw removal(CK), straw return(SR), and straw burned return(SBR). Compared to CK, long-term SR tended to improve the yield of early season rice(P=0.057), and significantly increased total organic carbon(TOC) and microbial biomass carbon(MBC) in double-cropped rice paddies. While SBR had no effect on TOC, it decreased light fraction organic carbon(LFOC) in early rice and easily oxidizable organic carbon(EOC) in late rice, significantly increased dissolved organic carbon(DOC), and significantly decreased soil p H. These results showed that MBC was the most sensitive indicator for assessing changes of SOC in the double-cropped rice system due to long-term straw return. In addition, the different effects on SOC fraction sizes between SR and SBR were attributed to the divergent trends in most of the soil enzyme activities in the early and late rice that mainly altered DOC, while DOC was positively affected by β-xylosidase in both early and late rice. We concluded that straw return was superior to straw burned return for improving SOC fractions, but the negative effects on soil enzyme activities in late rice require further research.
基金supported by the Guangdong Basic and Applied Basic Research Foundation,China(Grant No.2021A1515011255)Key-Area Research and Development Program of Guangdong Province,China(Grant No.2019B020221003)National Natural Science Foundation of China(Grant No.31471442)。
文摘To assess the effects of straw return coupled with deep nitrogen(N)fertilization on grain yield and N use efficiency(NUE)in mechanical pot-seedling transplanting(MPST)rice,the seedlings of two rice cultivars,i.e.,Yuxiangyouzhan and Wufengyou 615 transplanted by MPST were applied with N fertilizer at 150 kg/hm2 and straw return at 6 t/hm2 in early seasons of 2019 and 2020.The experiment comprised of following treatments:CK(no fertilizer and no straw return),MDS(deep N fertilization and straw return),MBS(broadcasting fertilizer and straw return),MD(deep N fertilization without straw return),MB(broadcasting fertilizer without straw return).Results depicted that the MDS treatment significantly increased the rice yield by 41.69%-72.22%due to total above-ground biomass,leaf area index and photosynthesis increased by 54.70%-55.80%,38.52%-52.17%and 17.89%-28.40%,respectively,compared to the MB treatment.In addition,the MDS treatment enhanced the total N accumulation by 37.74%-43.69%,N recovery efficiency by 141.45%-164.65%,N agronomic efficiency by 121.76%-134.19%,nitrate reductase by 46.46%-60.86%and glutamine synthetase by 23.56%-31.02%,compared to the MB treatment.The average grain yield and NUE in both years for Yuxiangyouzhan were higher in the MDS treatment than in the MD treatment.Hence,deep N fertilization combined with straw return can be an innovative technique with improved grain yield and NUE in MPST in South China.
基金supported by the Special Fund for Agroscientific Research in the Public Interest of China(201503122)the National Natural Science Foundation of China(31571622)。
文摘Straw return is an effective way to improve crop grain yield and potassium(K)use efficiency by increasing soil K content.However,the effects of straw return on soil K supplying capacity,replacement of K fertilizer,and K-use efficiency under maize(Zea mays L.)–rice(Oryza sativa L.)cropping systems are little studied.A two-year field experiment was conducted to determine the physiological determinants of K-use efficiency under straw return with four K fertilization rates.Sr33(straw returned plus 33%of K fertilizer applied)and Sr67(straw returned plus 67%of K fertilizer applied)increased annual crop yields by 1.5%and 3.2%and increased agronomic K-use efficiency by respectively 2.9 and 1.3-fold on average in the two years,compared with the conventional practice S0K100(no straw returned plus normal amounts of K fertilizer applied).The Sr33 and Sr67 treatments resulted in significantly greater equilibrium K concentration ratios(CR0 K)and specifically exchangeable K(KX)values according to quantity/intensity(Q/I)relationship analyses,indicating improvement of the potential soil K supply capacity.However,the Sr67 better maintained the soil exchangeable K level and K balance.The results suggested that K released from maize and rice straw can replace about half of chemical K fertilizer,depending on the available K content in maize–rice cropping system production.
基金the National Natural Science Foundation of China(42077022)Key Research and Development Program of Jilin Province(20200402098NC).
文摘Corn straw return to the field is a vital agronomic practice for increasing soil organic carbon(SOC)and its labile fractions,as well as soil aggregates and organic carbon(OC)associated with water-stable aggregates(WSA).Moreover,the labile SOC fractions play an important role in OC turnover and sequestration.The aims of this study were to determine how different corn straw returning modes affect the contents of labile SOC fractions and OC associated with WSA.Corn straw was returned in the following depths:(1)on undisturbed soil surface(NTS),(2)in the 0–10 cm soil depth(MTS),(3)in the 0–20 cm soil depth(CTS),and(4)no corn straw applied(CK).After five years(2014–2018),soil was sampled in the 0–20 and 20–40 cm depths to measure the water-extractable organic C(WEOC),permanganate oxidizable C(KMnO4-C),light fraction organic C(LFOC),and WSA fractions.The results showed that compared with CK,corn straw amended soils(NTS,MTS and CTS)increased SOC content by 11.55%–16.58%,WEOC by 41.38%–51.42%,KMnO4-C and LFOC by 29.84%–34.09%and 56.68%–65.36%in the 0–40 cm soil depth.The LFOC and KMnO4-C were proved to be the most sensitive fractions to different corn straw returning modes.Compared with CK,soils amended with corn straw increased mean weight diameter by 24.24%–40.48%in the 0–20 cm soil depth.The NTS and MTS preserved more than 60.00%of OC in macro-aggregates compared with CK.No significant difference was found in corn yield across all corn straw returning modes throughout the study period,indicating that adoption of NTS and MTS would increase SOC content and improve soil structure,and would not decline crop production.
基金financially supported by the National Key Research and Development Program of China(2021YFD1700901)the National Natural Science Foundation of China(31972519)+1 种基金the earmarked fund for China Agriculture Research System(CARS-01-33)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(2060302-05-956-1)。
文摘Straw incorporation is a widespread practice to promote agricultural sustainability.However,the potential effects of straw incorporation with the prolonged time on nitrogen(N)runoff loss from paddy fields are not well studied.The current study addresses the knowledge gap by assessing the effects of straw incorporation on the processes influencing N runoff patterns and its impacts on crop yield,N uptake,total N(TN),and soil organic matter(SOM).We conducted field experiments with rice(Oryza sativa L.)–wheat(Triticum aestivum L.)rotation,rice–tobacco(Nicotiana tabacum L.)rotation,and double-rice cropping in subtropical China from 2008 to 2012.Each rotation had three N treatments:zero N fertilization(CK),chemical N fertilization(CF),and chemical N fertilization combined with straw incorporation(CFS).The treatment effects were assessed on TN runoff loss,crop yield,N uptake,soil TN stock,and SOM.Results showed that TN runoff was reduced by substituting part of the chemical N fertilizer with straw N in the double rice rotation,while crop N uptake was significantly(P<0.05)decreased due to the lower bioavailability of straw N.In contrast,in both rice–wheat and rice–tobacco rotations,TN runoff in CFS was increased by 0.9–20.2%in the short term when straw N was applied in addition to chemical N,compared to CF.However,TN runoff was reduced by 2.3–19.3%after three years of straw incorporation,suggesting the long-term benefits of straw incorporation on TN loss reduction.Meanwhile,crop N uptake was increased by 0.8–37.3%in the CFS of both rotations.This study demonstrates the challenges in reducing N runoff loss while improving soil fertility by straw incorporation over the short term but highlights the potential of long-term straw incorporation to reduce N loss and improve soil productivity.
基金supported by the Agricultural Science and Technology Innovation Program (ASTIP) of Chinese Academy of Agricultural Sciences (CAAS-CSAL-202302 and GY2023-12-7)the Fundamental Research Funds for Central Non-Profit Scientific Institutions, China (1610132019014)the National Key Research and Development Program of China (2016YFD0200101 and 2018YFD0200804)。
文摘To understand the long-term effects of combined organic and chemical nitrogen fertilization on soil organic C(SOC) and total N(TN), we conducted a 30-year field experiment with a wheat–maize rotation system on the Huang-HuaiHai Plain during 1990–2019. The experimental treatments consisted of five fertilizer regimes: no fertilizer(control), chemical fertilizer only(NPK), chemical fertilizer with straw(NPKS), chemical fertilizer with manure(NPKM), and 1.5 times the rate of NPKM(1.5NPKM). The NPK, NPKS, and NPKM treatments had equal N inputs. The crop yields were measured over the whole experimental duration. Soil samples were collected from the topsoil(0–10 and 10–20 cm) and subsoil(20–40 cm) layers for assessing soil aggregates and taking SOC and TN measurements. Compared with the NPK treatment, the SOC and TN contents increased significantly in both the topsoil(24.1–44.4% for SOC and 22.8–47.7% for TN) and subsoil layers(22.0–47.9% for SOC and 19.8–41.8% for TN) for the organically amended treatments(NPKS, NPKM and 1.5NPKM) after 30 years, while no significant differences were found for the average annual crop yields over the 30 years of the experiment. The 0–10 cm layer of the NPKS treatment and the 20–40 cm layer of the NPKM treatment had significantly higher macroaggregate fraction mass proportions(19.8 and 27.0%) than the NPK treatment. However, the 0–10 and 20–40 cm layers of the 1.5NPKM treatment had significantly lower macroaggregate fraction mass proportions(–19.2 and –29.1%) than the control. The analysis showed that the higher SOC and TN in the soil of organically amended treatments compared to the NPK treatment were related to the increases in SOC and TN protected in the stable fractions(i.e., free microaggregates and microaggregates within macroaggregates), in which the contributions of the stable fractions were 81.1–91.7% of the increase in SOC and 83.3–94.0% of the increase in TN, respectively. The relationships between average C inputs and both stable SOC and TN stocks were significantly positive with R2 values of 0.74 and 0.72(P<0.01) for the whole 40 cm soil profile, which indicates the importance of N for soil C storage. The results of our study provide key evidence that long-term combined organic and chemical nitrogen fertilization, while maintaining reasonable total N inputs, benefited soil C and N storage in both the topsoil and subsoil layers.
基金We gratefully acknowledge the support provided by the:Earmarked Fund for“Modern Agro-industry Technology Research System”(CARS-01-46)National Key R&D Program“Research and Development of Biochar-Based Fertilizer and Microbial Fertilizer”(2017YFD0200800)+2 种基金Innovative Talents Promotion Plan of Ministry of Science and Technology(2017RA2211)Liaoning Revitalization Talents Program(No.XLYC1802094)Shenyang Support Plan for Young&Middle-aged Scientific and Technological Innovation Talents(RC180204).
文摘Biochar produced from straw has been shown to improve soil physicochemical properties.This review introduces the fundamental concepts,the broad applications,and underlying theory of straw biochar returning.Current developments in biochar industry and the production practices prevalent among enterprises in China are critiques.This review analyzes current knowledge gaps,challenges,and opportunities in the industrial application of straw biochar returning.Biochar standards,the quantitative and qualitative analysis methods for biochar,and high-value-added products that are based on biochar are critically examined with goal of providing recommendations for future studies.We propose production and modification of biochar that is application oriented to enhance its fitness for purpose as well as long-term and large-space-scale field study to better understand its impact on soil properties and ecotoxicology.Finally,we make prospects for the future development of SBR,including constructing a standard system about straw biochar returning and promoting self-discipline of biochar industry and the establishment of a biochar-based agricultural production model.
基金supported by the Major Science and Technological Innovation Project of Shandong Province(2019JZZY0110721)the National Natural Science Foundation of China(No.31600084)the National Key Research and Development Program of China(No.2017YFD0800403).
文摘Greenhouse vegetable cultivation(GVC)is an example of intensive agriculture aiming to increase crop yields by extending cultivation seasons and intensifying agricultural input.Compared with cropland,studies on the effects of farming management regimes on soil microorganisms of the GVC system are rare,and our knowledge is limited.In the present study,we assessed the impacts of different long-term fertilization regimes on soil fungal community structure changes in a greenhouse that has been applied in tomato(Solanum lycopersicum L.)cultivation for 11 consecutive years.Results showed that,when taking the non-fertilizer treatment of CK as a benchmark,both treatments of Conventional chemical N(CN)and Organic amendment only(MNS)significantly decreased the fungal richness by 16%–17%,while the Conventional chemical N and straw management(CNS)restored soil biodiversity at the same level.Saprotroph and pathotroph were the major trophic modes,and the abundance of the pathotroph fungi in treatment of CNS was significantly lower than those in CK and CN soils.The CNS treatment has significantly altered the fungal composition of the consecutive cropping soils by reducing the pathogens,e.g.,Trichothecium and Lecanicillium,and enriching the plant-beneficial,e.g.,Schizothecium.The CNS treatment is of crucial importance for sustainable development of the GVC system.
基金Financial supports from Natural Science Foundation of China(Nos. 41273095 and 40203011)Natural Science Foundation of Anhui Province(No. 2008085MD111)the University Synergy Innovation Program of Anhui Province(No. GXXT-2020075)
文摘As a common practice in agricultural system,straw return has been reported to release a large number of trace gases and attractedmuch attention.However,the role of straw return in toluene emission remains poorly understood.In this study we measured the emissions of toluene as well as other 50 volatile organic compounds(VOCs)from wheat straw return for 66 days under flooded and non-flooded conditions,respectively.The results showed that substantial toluene was released from the returned wheat straw particularly under flooded condition,and primarily derived from the secondary product.Toluene emissions from the returned wheat straw were 36.8 and 8.45 mg C/kg,sharing 28.0%and 8.6%of total VOCs released,and over 90% of toluene emissions occurred between days 24-56 and 0-17 under flooded and non-flooded conditions,respectively.The emission rates of toluene were relatively high but decreased sharply at the beginning 2 days,and then was steady until 24 days under the two moisture conditions.After the initial decrease these rose again to form one“peak emission window”between days 24-56 under flooded condition,while these were still very low and steady until the end under non-flooded condition.The toluene emission rates significantly positively correlated with microbial biomass C under flooded condition,but negatively associated with bacteria and fungus number,microbial biomass C,and CO_(2) flux under non-flooded condition,suggesting that microorganism might play an important role in toluene emissions from wheat straw return.A rough estimate indicated that straw return might be important for biogenic toluene.
基金National Natural Science Foundation of China(Nos.52160002,21707057,and 31860595)Natural Science Foundation of Jiangxi Province(No.20192BAB213018).
文摘Recently,returning straw to the fields has been proved as a direct and effective method to tackle soil nutrient loss and agricultural pollution.Meanwhile,the slow decomposition of straw may harm the growth of the next crop.This study aimed to determine the effects of rumen microorganisms(RMs)on straw decomposition,bacterial microbial community structure,soil properties,and soil enzyme activity.The results showed that RMs significantly enhanced the degradation rate of straw in the soil,reaching 39.52%,which was 41.37%higher than that of the control on the 30th day after straw return.After 30 d,straw degradation showed a significant slower trend in both the control and the experimental groups.According to the soil physicochemical parameters,the application of rumen fluid expedited soil matter transformation and nutrient buildup,and increased the urease,sucrase,and cellulase activity by 10%‒20%.The qualitative analysis of straw showed that the hydroxyl functional group structure of cellulose in straw was greatly damaged after the application of rumen fluid.The analysis of soil microbial community structure revealed that the addition of rumen fluid led to the proliferation of Actinobacteria with strong cellulose degradation ability,which was the main reason for the accelerated straw decomposition.Our study highlights that returning rice straw to the fields with rumen fluid inoculation can be used as an effective measure to enhance the biological value of recycled rice straw,proposing a viable solution to the problem of sluggish straw decomposition.
基金This work was supported by the China Agriculture Research System-Green Manure,the Virtual Joint Nitrogen Centre(N-Circle)(No.B B/N 013484/1)the Science and Technology Innovation Project of Chinese Academy of Agricultural Sciences(2013-2017)the Chinese Outstanding Talents Program in Agricultural Science.
文摘Returning rice straw and leguminous green manure alone or in combination to soil is effective in improving soil fertility in South China.Despite the popularity of this practice,our understanding o f the underlying processes for straw and manure combined application is relatively poor.In this study,rice straw(carbon(C)/nitrogen(N)ratio of 63),green manure(hairy vetch,C/N ratio of 14),and their mixtures(C/N ratio of 25 and 35)were added into a paddy soil,and their effects on soil N availability and C or N loss under waterlogged conditions were evaluated in a 100-d incubation experiment.All plant residue treatments significantly enhanced C〇2 and CH4 emissions,but decreased N2O emission.Dissolved organic C(DOC)and N(DON)and microbial biomass C in soil and water-soluble organic C and N and mineral N in the upper aqueous layer above soil were also enhanced by all the plant residue treatments except the rice straw treatment,and soil microbial biomass N and mineral N were lower in the rice straw treatment than in the other treatments.Changes in plant residue C/N ratio,DOC/DON ratio,and cellulose content significantly affected greenhouse gas emissions and active C and N concentrations in soil.Additionally,the treatment with green manure alone yielded the largest C and N losses,and incorporation of the plant residue mixture with a C/N ratio of 35 caused the largest net global warming potential(nGWP)among the amended treatments.In conclusion,the co-incorporation of rice straw and green manure can alleviate the limitation resulting from only applying rice straw(N immobilization)or the sole application of leguminous green manure(high C and N losses),and the residue mixture with a C/N ratio of 25 is a better option because of lower nGWP.
基金This work was partially supported by A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),the National Key R&D Program of China(Grant No.2018YFD0200500)the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences(Agricultural Academy Office(2014)No.216)+1 种基金and the Fundamental Research Funds for the Central Public Research Institutes(Grant No.S202010-02)The authors acknowledge the anonymous reviewers for their insightful comments on the manuscript.
文摘Crop straw is an important natural resource in China because it is rich in nutrients.When returned to fields after harvests,the straw can improve soil quality and the next crop’s yield.Evaluating the economic values of the main ecological services of a farmland ecosystem while implementing the straw return technique can be a more systematic and comprehensive approach to better understand the contribution of straw return to the development of ecological agriculture.Based on the data of a field experiment established in 2010 with varying numbers of years of straw return,four ecological services,i.e.,agricultural product and industrial raw materials,atmospheric regulation and purification,soil nutrient accumulation,and water conservation,were selected to estimate a net ecosystem service value(ESV)of a wheat field’s ecosystem services.Agro-ecosystem service appraisal theories were applied to estimate the economic value of each service.Results showed that straw returning improved the total ESV in the wheat system.Compared to the no straw return treatment,1 year,3 years,5 years or 7 years of straw returning altered the economic value of the agricultural product and industrial raw materials(EVAIM)by-5.93%to 7.84%and improved atmospheric regulation(EVAR)by 13.66%-30.80%,soil nutrient accumulation(EVSNA)by 59.87%-233.31%and water conservation(EVWC)by 2.60%-13.26%.The total ESV of wheat plots with 1-7 years of straw returning was 3.67%-27.41%higher than that with no straw return,and the total ESV increased with the increase in years of straw return.The proportion of EVAIM out of the total ESV in this wheat field system was highest(accounted for 47.09%-55.64%),followed by EVAR and EVWC.The value of EVSNA was the lowest.However,the proportion of EVSNA was higher than that of water conservation after the fifth year of straw return.In general,the adoption of continuous straw returning in a wheat field ecosystem is ecologically valuable.The results can inform the development and implementation of ecological compensation policies involving straw return.
基金Fundamental Research Funds for Central Non-profit Scientific Institution(Nos.1610132019011,1610132020012)the National Key Research and Development Program of China(Nos.2016YFD0800707,2016YFD0200109).
文摘Returning crop straw into the soil is an important practice to balance biogenic and bioavailable silicon(Si)pool in paddy,which is crucial for the healthy growth of rice.However,owing to little knowledge about soil microbial communities responsible for straw degradation,how straw return affects Si bioavailability,its uptake,and rice yield remains elusive.Herein,we investigate the change of soil Si fractions and microbial community in a 39-year-old paddy field amended by a long-term straw return.Results show that rice straw return significantly increased soil bioavailable Si and rice yield from 29.9%to 61.6%and from 14.5%to 23.6%,respectively,when compared to NPK fertilization alone.Straw return significantly altered soil microbial community abundance.Acidobacteria was positively and significantly related to amorphous Si,while Rokubacteria at phylum level,Deltaproteobacteria,and Holophagae at class level was negatively and significantly related to organic matter adsorbed and Fe/Mn-oxide-combined Si in soils.Redundancy analysis of their correlations further demonstrated that Si status significantly explained 12%of soil bacterial community variation.These findings suggest that soil bacteria community and diversity interact with Si mobility by altering its transformation,thus resulting in the balance of various nutrient sources to drive biological Si cycle in agroecosystem.
