Annual forage legumes are important components of livestock production systems in East Texas and the southeastern US. Forage legumes contribute nitrogen (N) to cropping systems through biological N fixation, and their...Annual forage legumes are important components of livestock production systems in East Texas and the southeastern US. Forage legumes contribute nitrogen (N) to cropping systems through biological N fixation, and their seasonal biomass production can be managed to complement forage grasses. Our research objectives were to evaluate both warm- and cool-season annual forage legumes as green manure for biomass, N content, ability to enhance soil organic carbon (SOC) and soil N, and impact on post season forage grass crops. Nine warm-season forage legumes (WSL) were spring planted and incorporated as green manure in the fall. Forage rye (Secale cereale L.) was planted following the incorporation of WSL treatments. Eight cool-season forage legumes (CSL) were fall planted in previously fallow plots and incorporated as green manure in late spring. Sorghum-sudangrass (Sorghum bicolor x Sorghum bicolor var. sudanense) was planted over all treatments in early summer after forage rye harvest and incorporation of CSL treatments. Sorghum-sudangrass was harvested in June, August and September, and treatments were evaluated for dry matter and N concentration. Soil cores were taken from each plot, split into depths of 0 to 15, 15 to 30 and 30 to 60 cm, and soil C and N were measured using combustion analysis. Nylon mesh bags containing plant samples were buried at 15 cm and used to evaluate decomposition rate of above ground legume biomass, including change in C and N concentrations. Mungbean (Vigna radiata L. [Wilczek]) had the highest shoot biomass yield (6.24 t DM ha<sup>-1</sup>) and contributed the most total N (167 kg∙ha<sup>-1</sup>) and total C (3043 kg∙ha<sup>-1</sup>) of the WSL tested. Decomposition rate of WSL biomass was rapid in the first 10 weeks and very slow afterward. Winter pea (Pisum sativum L. spp. sativum), arrow leaf clover (Trifolium vesiculosum Savi.), and crimson clover (Trifolium incarnatum L.) were the most productive CSL in this trial. Austrian winter pea produced 8.41 t DM ha<sup>-1</sup> with a total N yield of 319 kg N ha<sup>-1</sup> and total C production of 3835 kg C ha<sup>-1</sup>. The WSL treatments had only small effects on rye forage yield and N concentration, possibly due to mineralization of N from a large SOC pool already in place. The CSL treatments also had only minimal effects on sorghum-sudangrass forage production. Winter pea, arrow leaf and crimson clover were productive cool season legumes and could be useful as green manure crops. Mungbean and cowpea (Vigna unguiculata [L.] Walp.) were highly productive warm season legumes but may include more production risk in green manure systems due to soil moisture competition.展开更多
Green manure(GM)has been used to support rice production in southern China for thousands of years.However,the effects of GM on soil carbon sequestration(CS)and the carbon footprint(CF)at a regional scale remain unclea...Green manure(GM)has been used to support rice production in southern China for thousands of years.However,the effects of GM on soil carbon sequestration(CS)and the carbon footprint(CF)at a regional scale remain unclear.Therefore,we combined the datasets from long-term multisite experiments with a meta-analysis approach to quantify the potential of GM to increase the CS and reduce the CF of paddy soils in southern China.Compared with the fallow-rice practice,the GM-rice practice increased the soil C stock at a rate of 1.62 Mg CO_(2)-eq ha^(-1) yr^(-1) and reduced chemical N application by 40%with no loss in the rice yield.The total CF varied from 7.51 to 13.66 Mg CO_(2)-eq ha^(-1) yr^(-1) and was dominated by CH_(4) emissions(60.7-81.3%).GM decreased the indirect CF by 31.4%but increased the direct CH_(4) emissions by 19.6%.In the low and high CH_(4) emission scenarios,the CH_(4) emission factors of GM(EF_(gc))were 5.58 and 21.31%,respectively.The greater soil CS offset the increase in GM-derived CF in the low CH_(4) scenario,but it could not offset the CF increase in the high CH_(4) scenario.A trade-off analysis also showed that GM can simultaneously increase the CS and reduce the total CF of the rice production system when the EF_(gc) was less than 9.20%.The variation in EF_(gc) was mainly regulated by the GM application rates and water management patterns.Determining the appropriate GM application rate and drainage pattern warrant further investigation to optimize the potential of the GM-rice system to increase the CS and reduce the total CF in China.展开更多
To ascertain the possibility of cultivating maize using biological nitrogen fixation(BNF)by leguminous green manure crops in maize/leguminous green manure intercropping systems,BNF and nitrogen(N)transfer were studied...To ascertain the possibility of cultivating maize using biological nitrogen fixation(BNF)by leguminous green manure crops in maize/leguminous green manure intercropping systems,BNF and nitrogen(N)transfer were studied in Xining and Wuwei,two typical northwestern Chinese cities.The experimental treatments included monocultured maize,monocultured green manures(hairy vetch and common vetch),and their intercropping systems.The proportions of N derived from the atmosphere(%N_(dfa))in intercropping systems were not significantly different from that in monocultured green manure systems at either experimental site,except for that in hairy vetch(HV)in Xining.The amount of N derived from the atmosphere(N_(dfa))of common vetch(CV)significantly decreased from 1.16 and 1.10 g/pot in monoculture to 0.77 and 0.55 g/pot when intercropped with maize,in Xining and Wuwei,respectively,and the N_(dfa) of HV when intercropped significantly decreased from 1.02 to 0.48 g/pot in Xining.In the intercropping systems in Xining and Wuwei,the amounts of N transferred(N_(transfer))from CV to maize were 21.54 and 26.81 mg/pot,accounting for 32.9 and 5.9%respectively of the N accumulation in maize,and the values of N_(transfer) from HV to maize were 39.61 and 46.22 mg/pot,accounting for 37.0 and 23.3%,respectively,of the N accumulation in maize.Path analysis showed that soil nutrient and green manure biomass were mainly related to N_(dfa),and thatδ^(15) N had a primary relationship with N_(transfer).We found that 5.9-37.0%of N accumulation in maize was transferred from green manures,and that the N transfer ability to maize of HV was higher than that of CV.In conclusion,intercropping with leguminous green manures provided a feasible way for maize to effectively utilize biologicallyfixed N.展开更多
Green manure cover crops(GMCCs)planting has a potential for mitigating greenhouse gas emissions(GHG)in agroecosystems and provides important ecosystem services,thereby achieving the Sustainable Development Goals(SDGs)...Green manure cover crops(GMCCs)planting has a potential for mitigating greenhouse gas emissions(GHG)in agroecosystems and provides important ecosystem services,thereby achieving the Sustainable Development Goals(SDGs)stipulated by the United Nations.However,the advantages of cultivating GMCCs on arable land are not widely recognized.For example,in the whole of China,the GMCCs planting area is less than 3.5%of total arable land.The aim of this study is to explore reasons for the low adoption rate of GMCCs planting.Using best–worst scaling(BWS)approach,farmers ranked their preferred conservation practices including three types of GMCC cropping systems.Taking Gansu Province in Northwest China as a case study,a survey with 276 farmers was conducted.The findings indicated that three factors are related to the low adoption rate of GMCCs:1)farmers preferred improving farmland irrigation facilities and substituting chemical fertilizers with organic rather than planting GMCCs;2)lack of awareness and understanding of government policy on GMCCs and limited access to training courses;3)financial support and subsidies from the government are insufficient.This study provides insights and strategic implications for policymakers on how to further promote GMCCs in the future.展开更多
This study evaluates the effects of green manure, inorganic fertilizers and their combinations on the growth and yield of soybeans in the Mount Cameroon Region. The experiment involved 10 treatments which include, 5 M...This study evaluates the effects of green manure, inorganic fertilizers and their combinations on the growth and yield of soybeans in the Mount Cameroon Region. The experiment involved 10 treatments which include, 5 Mg/ha green manure, 180 Kg P/ha triple superphosphate fertilizer (P), 180 Kg/ha NPK (20:10:10), 2 Mg/ha green manure + 90 kg P/ha, 3 Mg/ha green manure + 90 kg P/ha, 5 Mg/ha green manure + 90 Kg P, 2 Mg/ha green manure + 90 kg NPK/ha, 3 Mg/ha green manure + 90 kg NPK/ha, 5 Mg/ha green manure + 90 kg NPK and a control. Plant growth characters were assessed every 14 days for a period of 70 days for the late (August) and early (March) planting seasons. The results indicated that plants supplied with 5 Mg/ha green manure had the highest plant heights of 60.7 cm, and this was significantly different from the control which had the least height (52.76 cm). Stem collar diameter was significantly (p 0.001) increased with treatments in both seasons. Plants supplied with 5 Mg/ha green manure recorded the highest stover yield (10.59 Mg/ha), and this was significantly different from the control which had the least (6.64 Mg/ha). Plants supplied with 5 Mg/ha green manure had the highest days to flowering (38 days), while plants supplied with 5 Mg/ha green manure + 90 Kg NPK had the least (33 days) which was significantly different (p 0.01). The highest number of pods per plant was observed in plants supplied with 5 Mg/ha green manure (57 pods per plants), which was significantly different from the control (39 pods per plant). Plants supplied with 5 Mg/ha green manure + 90 Kg NPK recorded the highest grain yield (4.97 Mg ha<sup>-1</sup>), while the lowest grain yield was observed in the control (2.22 Mg ha<sup>-1</sup>). Results from this study can be used by soybeans farmers in the Mount Cameroon region to enhance productivity of this crop and thereby improving their living standards and food security in Cameroon.展开更多
A long-term field experiment on organic material application and crop rotation with green manure crops has been conducted since 1976 at Lopburi Agricultural Research and Development Center,Department of Agriculture,Lo...A long-term field experiment on organic material application and crop rotation with green manure crops has been conducted since 1976 at Lopburi Agricultural Research and Development Center,Department of Agriculture,Lop Buri Province,Thailand,to clarify the effect of organic materials and green manure crop on soil organic carbon changes.The stock change factors that stand for the relative change of soil organic carbon on the carbon stock in a reference condition(native vegetation that is not degraded or improved).Stock change factor for input of organic matter(F1),representing different levels of C input to soil such as organic material application,crop residue treatment and green manure crop cultivation,was computed with the present field experimental results.While the computed F1 of"High input with manure"was within the range of IPCC default F1 value,some of the computed F1 of"High input without manure"was much higher than the IPCC default though it was varied due to the biomass production and nutrient contents of the green manure crops planted as the second crops after corn.Therefore,the F1 computed by field experimental results can contribute to more accurate estimation of SOC changes in farm land especially in Southeast Asia because the default F1 mostly depends on the experimental data in temperate zones.Moreover,the field experiment has focused the effect of reduced tillage practices on SOC changes and corn yield since 2011.The results of the experiment will be used to compute Stock change factor for management regime(FMC)which represents the effects of tillage operations.展开更多
Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.However,the mechanism by which green manuring manipulates the crop-associated microbial community remains to be...Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.However,the mechanism by which green manuring manipulates the crop-associated microbial community remains to be elucidated.In this study,we explored the horizontal processes of bacterial communities in different compartments of the soil–root interface(bulk soil,rhizosphere soil,rhizoplane and endosphere)of tobacco by performing a field experiment including four rotation practices,namely,tobacco rotated with smooth vetch,ryegrass,radish,and winter fallow(without green manure).Results showed that the co-occurrence networks constructed by adjacent compartments of the soil–root interface with green manuring had more edges than without green manuring,indicating dramatic microbial interactions.Green manuring increased the dispersal-niche continuum index between bulk soil and other compartments,indicating that it facilitated the horizontal dispersal of microbes.For the different green manuring practices,the neutral community model explained 24.6–27.6%of detection frequency for bacteria,and at least one compartment under each practice had a normalized stochasticity ratio higher than the 50%boundary point,suggesting that the deterministic and stochastic processes jointly shaped the tobacco microbiome.In conclusion,green manuring generally facilitates bacterial community dispersal across different compartments and enhances potential interactions among adjacent compartments.This study provides empirical evidence for understanding the microbiome assembly under green manure–crop rotation.展开更多
Cotton (</span><i><span style="font-family:Verdana;">Gossypium hirsutum </span></i><span style="font-family:Verdana;">L.) production in Oklahoma has more than tr...Cotton (</span><i><span style="font-family:Verdana;">Gossypium hirsutum </span></i><span style="font-family:Verdana;">L.) production in Oklahoma has more than tripled in the last ten years. This increase in cotton acreage in Oklahoma, a region that traditionally produces winter wheat, has led to increased incidences of 2,4 D contamination in sprayers that are used to spray cotton crops. Cotton is extremely sensitive to 2,4 D, with losses of yield and ultimately profit to the cotton producer in cases of drift or tank carryover. In this study, six cotton cultivars (three 2,4 D susceptible and three 2,4 D tolerant) were grown in combination </span></span><span style="font-family:Verdana;">with</span><span style="font-family:Verdana;"> four N treatments to determine the benefits or drawbacks of using a green manure as N source. Seedcotton, seed, and lint yield were all negatively impacted by 2,4 D in the susceptible cultivars. Additionally, water use was increased in the susceptible cultivars compared to the tolerant cultivars. The negative effects of 2,4 D on cotton growth w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> partially mitigated by grasspea, though </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">supply of too much nitrogen increased the negative effects of 2,4 D. Applying nitrogen to a susceptible cultivar of cotton contaminated by 2,4 D is not recommended for short season environments like Oklahoma</span><span style="font-family:Verdana;">.展开更多
Legume green manure is extensively planted to improve soil fertility in crop field.However,the application of legume in Eucalyptus plantation is still limited and depends on site specific and species.Therefore,the obj...Legume green manure is extensively planted to improve soil fertility in crop field.However,the application of legume in Eucalyptus plantation is still limited and depends on site specific and species.Therefore,the objective of this study was to determine the effects of green manure interplantation on soil fertility and plant growth of Eucalyptus plantation in a short term.A field experiment of one year was established to investigate the green manure growth,forest soil nutrients and Eucalyptus plant growth inter-planted with two legume species(Tephrosia candida,TC and Sesbania cannabina,SC)at south subtropical China.Legumes were inter-planted in linear among the tree space of Eucalyptus stand.Result showed that the green manure inter-plantation increased soil organic matter by 9.66%of TC and 18.44%of SC.Soil available nitrogen,phosphorus and potassium were improved significantly by the legume treatments as well.The increment of height and diameter at breast height of Eucalyptus during the experiment was significant in legume treatments.Thus,the timber volume increment was improved significantly by 46.81%of TC and 35.47%of SC compared with the control treatment.Therefore,the inter-plantation of legume green manure under the Eucalyptus plantation is effective to improve soil fertility and tree growth.Such a measure is potential and referenced for the sustainable forest management.展开更多
The aim of this study was to evaluate the physiological quality and seed production of Fabaceae and corn in monoculture and intercropping in areas cropped under different management. The following treatments were eval...The aim of this study was to evaluate the physiological quality and seed production of Fabaceae and corn in monoculture and intercropping in areas cropped under different management. The following treatments were evaluated: corn + NPK + weed control;corn + weed control;corn + NPK;corn + crotalaria;corn + jack bean. Intercropping raised the average number of corn ears of corn and the seed IVG Weed control positively influenced the final stand and average number of ears. NPK fertilization on corn sowing positively influenced the seed electrical conductivity. The yield of corn plants intercropped with crotalaria and jack bean was statistically similar. However, their absolute values should be considered for economic purposes. Corn seeds derived from intercropping with crotalaria were more effective compared with intercropping with jack bean. Crotalaria and jack bean seeds when intercropped with corn have high production, germination and vigor (IVG and emergence).展开更多
Astragalus sinicus is a commonly used legume green manure that fixes atmospheric N2 and accumulates mineral nutrients and organic substances that are beneficial to soils and subsequent crops.However,little is known ab...Astragalus sinicus is a commonly used legume green manure that fixes atmospheric N2 and accumulates mineral nutrients and organic substances that are beneficial to soils and subsequent crops.However,little is known about genotypic variation in,and molecular mechanisms of,Pi(phosphate)uptake and storage in A.sinicus.We recorded the morphological responses of six A.sinicus cultivars from four regions of China to external Pi application and measured their Pi accumulation.We identified full-length transcripts of Pi-signaling and Pi-homeostasis regulators by sequencing and measured the expression level of these genes by qRT-PCR.The major components in Pi signaling and Pi homeostasis were largely conserved between A.sinicus and the model species rice and Arabidopsis.Different A.sinicus varieties responded differently to low-phosphorus(P)stress,and their Pi accumulation was positively correlated with the expression of vacuolar Pi influx gene(SYG1/PHO81/XPR1-MAJOR FACILITATOR SUPERFAMILY(SPX-MFS)-TYPE PROTEIN)AsSPXMFS2 and negatively correlated with the expression of the vacuolar Pi efflux gene(VACUOLAR Pi EFFLUX TRANSPORTER)AsVPE1.We identified key Pi-signaling and Pihomeostasis regulators in A.sinicus.The expression of vacuolar Pi transporter genes could be used as an index to select A.sinicus accessions with high Pi accumulation.展开更多
Propagation of native species in local nurseries is an important activity in reforestation and forest restoration programs. A requisite for successful plantation is that nursery produced plants are of a size and quali...Propagation of native species in local nurseries is an important activity in reforestation and forest restoration programs. A requisite for successful plantation is that nursery produced plants are of a size and quality that allows optimal establishment under field conditions. Manipulation of edaphic processes through the combined use of the earthworm Pontoscolex corethrurus, Mucuna pruriens and inorganic fertilizers may promote faster biomass gain. This study assessed the activity of P. corethrurus, its association with M. pruriens (green manure) and inorganic fertilizers, on the growth of Quercus insignis seedlings under greenhouse conditions. Measured variables were basal diameter, height, biomass and foliar nitrogen content. Growth rates of basal diameter (F = 5.33;P F = 2.84;P P. corethrurus-M. pruriens-inorganic fertilizer, relative to the control. Also, leaf biomass and total biomass of the seedlings were greater in the treatment of P. corethrurus-fertilizer (F = 2.32;P F = 3.71;P Foliar nitrogen content <span style="font-family:Verdana;展开更多
Soil soluble organic nitrogen(SON)is one of the most active components in soil nitrogen pools;however,limited information is available with regard to its driving factors,as well as their pathways and degrees of influe...Soil soluble organic nitrogen(SON)is one of the most active components in soil nitrogen pools;however,limited information is available with regard to its driving factors,as well as their pathways and degrees of influence.In this study,structural equation modeling was used to analyze the driving factors,their significance,and pathways that affected SON dynamics in a waterlogged experiment of two typical paddy soils incubated for 80 d after green manure application.Soil p H,Eh,microbial biomass,enzyme activity,and SON dynamics were used to construct the structural equation model.Results showed that soil microbial biomass carbon(MBC),protease,glutamine,and initial organic matter(OM)directly and significantly affected soil SON with path coefficients corresponding to 0.405,0.547,0.523,and-0.623(P<0.01),respectively.Soil microbial biomass carbon and initial OM affected the SON dynamics indirectly through protease and glutamine activity.In addition,pH indirectly affected SON dynamics by glutamine activity.It is implied that soil MBC,protease,glutamine,and initial OM are the key factors affecting SON dynamics in the waterlogged paddy soils after green manure application.Our research indicated that structural equation modeling could provide an effective method to clearly recognize the impact,significance,and pathways of multiple factors on SON dynamics in paddy soils.展开更多
The return of crop residue and green manure into agricultural soil is known to be important agricultural management strategies,yet how they affect the anammox process remains poorly characterized.A field experiment co...The return of crop residue and green manure into agricultural soil is known to be important agricultural management strategies,yet how they affect the anammox process remains poorly characterized.A field experiment containing four treatments:chemical fertilizer(F),F plus rice straw(FS),FS plus green manure(FSM),FSM with integrated management(FSMM),was performed to examine the effects of incorporation of rice straw and green manure residues on anammox.The results showed that the anammox activities in FS and FSM treatments(0.65 and 0.80 nmol N g^(–1)soil h^(–1),respectively)were significantly lower than those in F and FSMM treatments(1.60 and 1.28 nmol N g^(–1)soil h^(–1),respectively).Anammox contributed 4.07%-4.95%of total N loss in soil incorporated with residues,lower than soil treated with chemical fertilizer only(9.13%),the remaining being due to denitrification.However,the abundance of the hzsB gene(the hydrazine synthaseβ-subunit gene)in FS and FSM treatments(1.13106 and 1.18106 copies g^(–1)soil)were significantly higher than soil using chemical fertilizer only(7.49105 copies g^(–1)soil)while showed no significant difference with FSMM treatment(8.81105 copies g^(–1)soil).Illumina sequencing indicated that Brocadia was the dominant anammox genus,following by Scalindua and Kuenenia.Anammox bacterial diversity was altered after 4-year incorporation of rice straw and green manure,as shown byα-diversity indices.We concluded that rice straw and green manure incorporated with mineral fertilizer reduce N removal from paddy soil in terms of anammox in spite of stimulating anammox bacterial growth.展开更多
文摘Annual forage legumes are important components of livestock production systems in East Texas and the southeastern US. Forage legumes contribute nitrogen (N) to cropping systems through biological N fixation, and their seasonal biomass production can be managed to complement forage grasses. Our research objectives were to evaluate both warm- and cool-season annual forage legumes as green manure for biomass, N content, ability to enhance soil organic carbon (SOC) and soil N, and impact on post season forage grass crops. Nine warm-season forage legumes (WSL) were spring planted and incorporated as green manure in the fall. Forage rye (Secale cereale L.) was planted following the incorporation of WSL treatments. Eight cool-season forage legumes (CSL) were fall planted in previously fallow plots and incorporated as green manure in late spring. Sorghum-sudangrass (Sorghum bicolor x Sorghum bicolor var. sudanense) was planted over all treatments in early summer after forage rye harvest and incorporation of CSL treatments. Sorghum-sudangrass was harvested in June, August and September, and treatments were evaluated for dry matter and N concentration. Soil cores were taken from each plot, split into depths of 0 to 15, 15 to 30 and 30 to 60 cm, and soil C and N were measured using combustion analysis. Nylon mesh bags containing plant samples were buried at 15 cm and used to evaluate decomposition rate of above ground legume biomass, including change in C and N concentrations. Mungbean (Vigna radiata L. [Wilczek]) had the highest shoot biomass yield (6.24 t DM ha<sup>-1</sup>) and contributed the most total N (167 kg∙ha<sup>-1</sup>) and total C (3043 kg∙ha<sup>-1</sup>) of the WSL tested. Decomposition rate of WSL biomass was rapid in the first 10 weeks and very slow afterward. Winter pea (Pisum sativum L. spp. sativum), arrow leaf clover (Trifolium vesiculosum Savi.), and crimson clover (Trifolium incarnatum L.) were the most productive CSL in this trial. Austrian winter pea produced 8.41 t DM ha<sup>-1</sup> with a total N yield of 319 kg N ha<sup>-1</sup> and total C production of 3835 kg C ha<sup>-1</sup>. The WSL treatments had only small effects on rye forage yield and N concentration, possibly due to mineralization of N from a large SOC pool already in place. The CSL treatments also had only minimal effects on sorghum-sudangrass forage production. Winter pea, arrow leaf and crimson clover were productive cool season legumes and could be useful as green manure crops. Mungbean and cowpea (Vigna unguiculata [L.] Walp.) were highly productive warm season legumes but may include more production risk in green manure systems due to soil moisture competition.
基金supported by the National Key Research and Development Program of China(2021YFD1700200)the earmarked fund for China Agriculture Research System(CARS-22).
文摘Green manure(GM)has been used to support rice production in southern China for thousands of years.However,the effects of GM on soil carbon sequestration(CS)and the carbon footprint(CF)at a regional scale remain unclear.Therefore,we combined the datasets from long-term multisite experiments with a meta-analysis approach to quantify the potential of GM to increase the CS and reduce the CF of paddy soils in southern China.Compared with the fallow-rice practice,the GM-rice practice increased the soil C stock at a rate of 1.62 Mg CO_(2)-eq ha^(-1) yr^(-1) and reduced chemical N application by 40%with no loss in the rice yield.The total CF varied from 7.51 to 13.66 Mg CO_(2)-eq ha^(-1) yr^(-1) and was dominated by CH_(4) emissions(60.7-81.3%).GM decreased the indirect CF by 31.4%but increased the direct CH_(4) emissions by 19.6%.In the low and high CH_(4) emission scenarios,the CH_(4) emission factors of GM(EF_(gc))were 5.58 and 21.31%,respectively.The greater soil CS offset the increase in GM-derived CF in the low CH_(4) scenario,but it could not offset the CF increase in the high CH_(4) scenario.A trade-off analysis also showed that GM can simultaneously increase the CS and reduce the total CF of the rice production system when the EF_(gc) was less than 9.20%.The variation in EF_(gc) was mainly regulated by the GM application rates and water management patterns.Determining the appropriate GM application rate and drainage pattern warrant further investigation to optimize the potential of the GM-rice system to increase the CS and reduce the total CF in China.
基金financially supported by the China Agriculture Research System of MOF and MARA(CARS22)the National Natural Science Foundation of China(32072678)+3 种基金the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2020)the Chinese Outstanding Talents Program in Agricultural Sciencethe Protection and Utilization of Crop Germplasm Resources of China Green Manure(19200393)the Fund Project of Qinghai Academy of Agricultural Sciences(2019-NKY-06)。
文摘To ascertain the possibility of cultivating maize using biological nitrogen fixation(BNF)by leguminous green manure crops in maize/leguminous green manure intercropping systems,BNF and nitrogen(N)transfer were studied in Xining and Wuwei,two typical northwestern Chinese cities.The experimental treatments included monocultured maize,monocultured green manures(hairy vetch and common vetch),and their intercropping systems.The proportions of N derived from the atmosphere(%N_(dfa))in intercropping systems were not significantly different from that in monocultured green manure systems at either experimental site,except for that in hairy vetch(HV)in Xining.The amount of N derived from the atmosphere(N_(dfa))of common vetch(CV)significantly decreased from 1.16 and 1.10 g/pot in monoculture to 0.77 and 0.55 g/pot when intercropped with maize,in Xining and Wuwei,respectively,and the N_(dfa) of HV when intercropped significantly decreased from 1.02 to 0.48 g/pot in Xining.In the intercropping systems in Xining and Wuwei,the amounts of N transferred(N_(transfer))from CV to maize were 21.54 and 26.81 mg/pot,accounting for 32.9 and 5.9%respectively of the N accumulation in maize,and the values of N_(transfer) from HV to maize were 39.61 and 46.22 mg/pot,accounting for 37.0 and 23.3%,respectively,of the N accumulation in maize.Path analysis showed that soil nutrient and green manure biomass were mainly related to N_(dfa),and thatδ^(15) N had a primary relationship with N_(transfer).We found that 5.9-37.0%of N accumulation in maize was transferred from green manures,and that the N transfer ability to maize of HV was higher than that of CV.In conclusion,intercropping with leguminous green manures provided a feasible way for maize to effectively utilize biologicallyfixed N.
基金support from the National Social Science Fund of China(18ZDA048)。
文摘Green manure cover crops(GMCCs)planting has a potential for mitigating greenhouse gas emissions(GHG)in agroecosystems and provides important ecosystem services,thereby achieving the Sustainable Development Goals(SDGs)stipulated by the United Nations.However,the advantages of cultivating GMCCs on arable land are not widely recognized.For example,in the whole of China,the GMCCs planting area is less than 3.5%of total arable land.The aim of this study is to explore reasons for the low adoption rate of GMCCs planting.Using best–worst scaling(BWS)approach,farmers ranked their preferred conservation practices including three types of GMCC cropping systems.Taking Gansu Province in Northwest China as a case study,a survey with 276 farmers was conducted.The findings indicated that three factors are related to the low adoption rate of GMCCs:1)farmers preferred improving farmland irrigation facilities and substituting chemical fertilizers with organic rather than planting GMCCs;2)lack of awareness and understanding of government policy on GMCCs and limited access to training courses;3)financial support and subsidies from the government are insufficient.This study provides insights and strategic implications for policymakers on how to further promote GMCCs in the future.
文摘This study evaluates the effects of green manure, inorganic fertilizers and their combinations on the growth and yield of soybeans in the Mount Cameroon Region. The experiment involved 10 treatments which include, 5 Mg/ha green manure, 180 Kg P/ha triple superphosphate fertilizer (P), 180 Kg/ha NPK (20:10:10), 2 Mg/ha green manure + 90 kg P/ha, 3 Mg/ha green manure + 90 kg P/ha, 5 Mg/ha green manure + 90 Kg P, 2 Mg/ha green manure + 90 kg NPK/ha, 3 Mg/ha green manure + 90 kg NPK/ha, 5 Mg/ha green manure + 90 kg NPK and a control. Plant growth characters were assessed every 14 days for a period of 70 days for the late (August) and early (March) planting seasons. The results indicated that plants supplied with 5 Mg/ha green manure had the highest plant heights of 60.7 cm, and this was significantly different from the control which had the least height (52.76 cm). Stem collar diameter was significantly (p 0.001) increased with treatments in both seasons. Plants supplied with 5 Mg/ha green manure recorded the highest stover yield (10.59 Mg/ha), and this was significantly different from the control which had the least (6.64 Mg/ha). Plants supplied with 5 Mg/ha green manure had the highest days to flowering (38 days), while plants supplied with 5 Mg/ha green manure + 90 Kg NPK had the least (33 days) which was significantly different (p 0.01). The highest number of pods per plant was observed in plants supplied with 5 Mg/ha green manure (57 pods per plants), which was significantly different from the control (39 pods per plant). Plants supplied with 5 Mg/ha green manure + 90 Kg NPK recorded the highest grain yield (4.97 Mg ha<sup>-1</sup>), while the lowest grain yield was observed in the control (2.22 Mg ha<sup>-1</sup>). Results from this study can be used by soybeans farmers in the Mount Cameroon region to enhance productivity of this crop and thereby improving their living standards and food security in Cameroon.
文摘A long-term field experiment on organic material application and crop rotation with green manure crops has been conducted since 1976 at Lopburi Agricultural Research and Development Center,Department of Agriculture,Lop Buri Province,Thailand,to clarify the effect of organic materials and green manure crop on soil organic carbon changes.The stock change factors that stand for the relative change of soil organic carbon on the carbon stock in a reference condition(native vegetation that is not degraded or improved).Stock change factor for input of organic matter(F1),representing different levels of C input to soil such as organic material application,crop residue treatment and green manure crop cultivation,was computed with the present field experimental results.While the computed F1 of"High input with manure"was within the range of IPCC default F1 value,some of the computed F1 of"High input without manure"was much higher than the IPCC default though it was varied due to the biomass production and nutrient contents of the green manure crops planted as the second crops after corn.Therefore,the F1 computed by field experimental results can contribute to more accurate estimation of SOC changes in farm land especially in Southeast Asia because the default F1 mostly depends on the experimental data in temperate zones.Moreover,the field experiment has focused the effect of reduced tillage practices on SOC changes and corn yield since 2011.The results of the experiment will be used to compute Stock change factor for management regime(FMC)which represents the effects of tillage operations.
基金supported financially by the National Key Research and Development Program of China(2021YFD1700200)the China Agriculture Research System of MOF and MARA(CARS-22).
文摘Green manure–crop rotation is a sustainable approach to protect crops against diseases and improve yield.However,the mechanism by which green manuring manipulates the crop-associated microbial community remains to be elucidated.In this study,we explored the horizontal processes of bacterial communities in different compartments of the soil–root interface(bulk soil,rhizosphere soil,rhizoplane and endosphere)of tobacco by performing a field experiment including four rotation practices,namely,tobacco rotated with smooth vetch,ryegrass,radish,and winter fallow(without green manure).Results showed that the co-occurrence networks constructed by adjacent compartments of the soil–root interface with green manuring had more edges than without green manuring,indicating dramatic microbial interactions.Green manuring increased the dispersal-niche continuum index between bulk soil and other compartments,indicating that it facilitated the horizontal dispersal of microbes.For the different green manuring practices,the neutral community model explained 24.6–27.6%of detection frequency for bacteria,and at least one compartment under each practice had a normalized stochasticity ratio higher than the 50%boundary point,suggesting that the deterministic and stochastic processes jointly shaped the tobacco microbiome.In conclusion,green manuring generally facilitates bacterial community dispersal across different compartments and enhances potential interactions among adjacent compartments.This study provides empirical evidence for understanding the microbiome assembly under green manure–crop rotation.
文摘Cotton (</span><i><span style="font-family:Verdana;">Gossypium hirsutum </span></i><span style="font-family:Verdana;">L.) production in Oklahoma has more than tripled in the last ten years. This increase in cotton acreage in Oklahoma, a region that traditionally produces winter wheat, has led to increased incidences of 2,4 D contamination in sprayers that are used to spray cotton crops. Cotton is extremely sensitive to 2,4 D, with losses of yield and ultimately profit to the cotton producer in cases of drift or tank carryover. In this study, six cotton cultivars (three 2,4 D susceptible and three 2,4 D tolerant) were grown in combination </span></span><span style="font-family:Verdana;">with</span><span style="font-family:Verdana;"> four N treatments to determine the benefits or drawbacks of using a green manure as N source. Seedcotton, seed, and lint yield were all negatively impacted by 2,4 D in the susceptible cultivars. Additionally, water use was increased in the susceptible cultivars compared to the tolerant cultivars. The negative effects of 2,4 D on cotton growth w</span><span style="font-family:Verdana;">ere</span><span style="font-family:Verdana;"> partially mitigated by grasspea, though </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">supply of too much nitrogen increased the negative effects of 2,4 D. Applying nitrogen to a susceptible cultivar of cotton contaminated by 2,4 D is not recommended for short season environments like Oklahoma</span><span style="font-family:Verdana;">.
基金The authors are grateful forfinancial support from Guangxi Zhuang Autonomous Region(AA17204087-11)Aids in sampling from the members of National Dongmen Forest Farm of Guangxi Zhuang Autonomous Region are appreciated.
文摘Legume green manure is extensively planted to improve soil fertility in crop field.However,the application of legume in Eucalyptus plantation is still limited and depends on site specific and species.Therefore,the objective of this study was to determine the effects of green manure interplantation on soil fertility and plant growth of Eucalyptus plantation in a short term.A field experiment of one year was established to investigate the green manure growth,forest soil nutrients and Eucalyptus plant growth inter-planted with two legume species(Tephrosia candida,TC and Sesbania cannabina,SC)at south subtropical China.Legumes were inter-planted in linear among the tree space of Eucalyptus stand.Result showed that the green manure inter-plantation increased soil organic matter by 9.66%of TC and 18.44%of SC.Soil available nitrogen,phosphorus and potassium were improved significantly by the legume treatments as well.The increment of height and diameter at breast height of Eucalyptus during the experiment was significant in legume treatments.Thus,the timber volume increment was improved significantly by 46.81%of TC and 35.47%of SC compared with the control treatment.Therefore,the inter-plantation of legume green manure under the Eucalyptus plantation is effective to improve soil fertility and tree growth.Such a measure is potential and referenced for the sustainable forest management.
文摘The aim of this study was to evaluate the physiological quality and seed production of Fabaceae and corn in monoculture and intercropping in areas cropped under different management. The following treatments were evaluated: corn + NPK + weed control;corn + weed control;corn + NPK;corn + crotalaria;corn + jack bean. Intercropping raised the average number of corn ears of corn and the seed IVG Weed control positively influenced the final stand and average number of ears. NPK fertilization on corn sowing positively influenced the seed electrical conductivity. The yield of corn plants intercropped with crotalaria and jack bean was statistically similar. However, their absolute values should be considered for economic purposes. Corn seeds derived from intercropping with crotalaria were more effective compared with intercropping with jack bean. Crotalaria and jack bean seeds when intercropped with corn have high production, germination and vigor (IVG and emergence).
基金supported by the China Agriculture Research System-Green Manure(CARS-22)the Innovation Program of Chinese Academy of Agricultural Sciences。
文摘Astragalus sinicus is a commonly used legume green manure that fixes atmospheric N2 and accumulates mineral nutrients and organic substances that are beneficial to soils and subsequent crops.However,little is known about genotypic variation in,and molecular mechanisms of,Pi(phosphate)uptake and storage in A.sinicus.We recorded the morphological responses of six A.sinicus cultivars from four regions of China to external Pi application and measured their Pi accumulation.We identified full-length transcripts of Pi-signaling and Pi-homeostasis regulators by sequencing and measured the expression level of these genes by qRT-PCR.The major components in Pi signaling and Pi homeostasis were largely conserved between A.sinicus and the model species rice and Arabidopsis.Different A.sinicus varieties responded differently to low-phosphorus(P)stress,and their Pi accumulation was positively correlated with the expression of vacuolar Pi influx gene(SYG1/PHO81/XPR1-MAJOR FACILITATOR SUPERFAMILY(SPX-MFS)-TYPE PROTEIN)AsSPXMFS2 and negatively correlated with the expression of the vacuolar Pi efflux gene(VACUOLAR Pi EFFLUX TRANSPORTER)AsVPE1.We identified key Pi-signaling and Pihomeostasis regulators in A.sinicus.The expression of vacuolar Pi transporter genes could be used as an index to select A.sinicus accessions with high Pi accumulation.
基金the Con-sejo Nacional de Ciencia y Tecnología(CONACYT)for the scholarship granted for this research(Num.Reg.223896)funding received by the Sectorial Fund for Edu-cation Research SEP-CONACYT(project CB-2010-0-156053).
文摘Propagation of native species in local nurseries is an important activity in reforestation and forest restoration programs. A requisite for successful plantation is that nursery produced plants are of a size and quality that allows optimal establishment under field conditions. Manipulation of edaphic processes through the combined use of the earthworm Pontoscolex corethrurus, Mucuna pruriens and inorganic fertilizers may promote faster biomass gain. This study assessed the activity of P. corethrurus, its association with M. pruriens (green manure) and inorganic fertilizers, on the growth of Quercus insignis seedlings under greenhouse conditions. Measured variables were basal diameter, height, biomass and foliar nitrogen content. Growth rates of basal diameter (F = 5.33;P F = 2.84;P P. corethrurus-M. pruriens-inorganic fertilizer, relative to the control. Also, leaf biomass and total biomass of the seedlings were greater in the treatment of P. corethrurus-fertilizer (F = 2.32;P F = 3.71;P Foliar nitrogen content <span style="font-family:Verdana;
基金supported by the National Natural Science Foundation of China(No.41671490)the Science and Technology Innovation Fund Project of Fujian Agriculture and Forestry University,China(No.KF2105074)
文摘Soil soluble organic nitrogen(SON)is one of the most active components in soil nitrogen pools;however,limited information is available with regard to its driving factors,as well as their pathways and degrees of influence.In this study,structural equation modeling was used to analyze the driving factors,their significance,and pathways that affected SON dynamics in a waterlogged experiment of two typical paddy soils incubated for 80 d after green manure application.Soil p H,Eh,microbial biomass,enzyme activity,and SON dynamics were used to construct the structural equation model.Results showed that soil microbial biomass carbon(MBC),protease,glutamine,and initial organic matter(OM)directly and significantly affected soil SON with path coefficients corresponding to 0.405,0.547,0.523,and-0.623(P<0.01),respectively.Soil microbial biomass carbon and initial OM affected the SON dynamics indirectly through protease and glutamine activity.In addition,pH indirectly affected SON dynamics by glutamine activity.It is implied that soil MBC,protease,glutamine,and initial OM are the key factors affecting SON dynamics in the waterlogged paddy soils after green manure application.Our research indicated that structural equation modeling could provide an effective method to clearly recognize the impact,significance,and pathways of multiple factors on SON dynamics in paddy soils.
基金Joint Regional Innovation and Development Fund(UI9A2048)the National Key Research and Development Program of China(2016YFD0300901,2016YFD0300906)+1 种基金the Natural Science Foundation of Hunan Province(2019JJ50338)the National Natural Science Foundation of China(4170010194)。
文摘The return of crop residue and green manure into agricultural soil is known to be important agricultural management strategies,yet how they affect the anammox process remains poorly characterized.A field experiment containing four treatments:chemical fertilizer(F),F plus rice straw(FS),FS plus green manure(FSM),FSM with integrated management(FSMM),was performed to examine the effects of incorporation of rice straw and green manure residues on anammox.The results showed that the anammox activities in FS and FSM treatments(0.65 and 0.80 nmol N g^(–1)soil h^(–1),respectively)were significantly lower than those in F and FSMM treatments(1.60 and 1.28 nmol N g^(–1)soil h^(–1),respectively).Anammox contributed 4.07%-4.95%of total N loss in soil incorporated with residues,lower than soil treated with chemical fertilizer only(9.13%),the remaining being due to denitrification.However,the abundance of the hzsB gene(the hydrazine synthaseβ-subunit gene)in FS and FSM treatments(1.13106 and 1.18106 copies g^(–1)soil)were significantly higher than soil using chemical fertilizer only(7.49105 copies g^(–1)soil)while showed no significant difference with FSMM treatment(8.81105 copies g^(–1)soil).Illumina sequencing indicated that Brocadia was the dominant anammox genus,following by Scalindua and Kuenenia.Anammox bacterial diversity was altered after 4-year incorporation of rice straw and green manure,as shown byα-diversity indices.We concluded that rice straw and green manure incorporated with mineral fertilizer reduce N removal from paddy soil in terms of anammox in spite of stimulating anammox bacterial growth.
