Synthetic nitrogen(N)fertilizer has made a great contribution to the improvement of soil fertility and productivity,but excessive application of synthetic N fertilizer may cause agroecosystem risks,such as soil acidif...Synthetic nitrogen(N)fertilizer has made a great contribution to the improvement of soil fertility and productivity,but excessive application of synthetic N fertilizer may cause agroecosystem risks,such as soil acidification,groundwater contamination and biodiversity reduction.Meanwhile,organic substitution has received increasing attention for its ecologically and environmentally friendly and productivity benefits.However,the linkages between manure substitution,crop yield and the underlying microbial mechanisms remain uncertain.To bridge this gap,a three-year field experiment was conducted with five fertilization regimes:i)Control,non-fertilization;CF,conventional synthetic fertilizer application;CF_(1/2)M_(1/2),1/2 N input via synthetic fertilizer and 1/2 N input via manure;CF_(1/4)M_(3/4),1/4 N input synthetic fertilizer and 3/4 N input via manure;M,manure application.All fertilization treatments were designed to have equal N input.Our results showed that all manure substituted treatments achieved high soil fertility indexes(SFI)and productivities by increasing the soil organic carbon(SOC),total N(TN)and available phosphorus(AP)concentrations,and by altering the bacterial community diversity and composition compared with CF.SOC,AP,and the soil C:N ratio were mainly responsible for microbial community variations.The co-occurrence network revealed that SOC and AP had strong positive associations with Rhodospirillales and Burkholderiales,while TN and C:N ratio had positive and negative associations with Micromonosporaceae,respectively.These specific taxa are implicated in soil macroelement turnover.Random Forest analysis predicted that both biotic(bacterial composition and Micromonosporaceae)and abiotic(AP,SOC,SFI,and TN)factors had significant effects on crop yield.The present work strengthens our understanding of the effects of manure substitution on crop yield and provides theoretical support for optimizing fertilization strategies.展开更多
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
Manure management is an essential component of dairy production. Nutrient-laden, field-applied dairy manure often serves as a fertilizer source, but can also pose environmental threats if not properly managed. The Haa...Manure management is an essential component of dairy production. Nutrient-laden, field-applied dairy manure often serves as a fertilizer source, but can also pose environmental threats if not properly managed. The Haak dairy farm, located in Decatur, Arkansas, was granted a permit by the Arkansas Department of Environmental Quality (ADEQ) to employ a unique method in treating and storing cattle manure generated during the milking process. This method includes minimizing water use in wash water, dry scraping solids to combine with sawdust for composting and pumping effluent underground into a sloped concrete basin that serves as secondary solid separator before transporting the manure effluent into an interception trench and an adjacent grassed field to facilitate manure nutrient uptake and retention. The Arkansas Discovery Farm program (ADF) is conducting research to evaluate the environmental performance of the dairy’s milk center wash water treatment system (MCWW) by statistical analysis, characterization of phosphorus (P) migration in soil downslope from the inception trench, temperature measurements, and nutrient analysis of a stored dry stack manure/sawdust mixture. Goals included determining possible composting effectiveness along with comparisons to untreated dairy manure and quantifying the use of on-farm water. Results from this research demonstrated that: 1) The MCWW was effective at retaining manure-derived nutrients and reducing field nutrient migration as the MCWW interception trench had significantly higher total nitrogen (TN) (804.2 to 4.1), total phosphorus (TP) (135.6 to 1.5), and water extractable phosphorus (WEP) (55.0 to 1.0) concentrations in milligrams per liter (mg⋅L<sup>-1</sup>) than the downhill freshwater pond respectively;2) temperature readings of the manure dry stack indicated heightened levels of microbial and thermal activity, but did not reach a standard composting temperature of 54°C;3) manure dry stack nutrient content was typically higher than untreated dairy manure when measured on a “dry basis” in ppm, but was lower on an “as is basis” in ppm and kg/metric ton;and 4) water meter readings showed that the greatest use of on-farm water was for farm-wide cattle drinking (18.77), followed by water used in the milking center (3.45) and then followed by human usage (0.02) measured in cubic meters per day (m<sup>3</sup>⋅d<sup>-1</sup>). These results demonstrate that practical innovations in agricultural engineering and environmental science, such as the Haak dairy’s manure treatment system, can effectively reduce environmental hazards that accompany the management of manure at this dairy operation.展开更多
Combined application of chemical fertilizers with organic amendments was recommended as a strategy for improving yield,soil carbon storage,and nutrient use efficiency.However,how the long-term substitution of chemical...Combined application of chemical fertilizers with organic amendments was recommended as a strategy for improving yield,soil carbon storage,and nutrient use efficiency.However,how the long-term substitution of chemical fertilizer with organic manure affects rice yield,carbon sequestration rate(CSR),and nitrogen use efficiency(NUE)while ensuring environmental safety remains unclear.This study assessed the long-term effect of substituting chemical fertilizer with organic manure on rice yield,CSR,and NUE.It also determined the optimum substitution ratio in the acidic soil of southern China.The treatments were:(i)NPK0,unfertilized control;(ii)NPK1,100%chemical nitrogen,phosphorus,and potassium fertilizer;(iii)NPKM1,70%chemical NPK fertilizer and 30%organic manure;(iv)NPKM2,50%chemical NPK fertilizer and 50%organic manure;and(v)NPKM3,30%chemical NPK fertilizer and 70%organic manure.Milk vetch and pig manure were sources of manure for early and late rice seasons,respectively.The result showed that SOC content was higher in NPKM1,NPKM2,and NPKM3 treatments than in NPK0 and NPK1 treatments.The carbon sequestration rate increased by 140,160,and 280%under NPKM1,NPKM2,and NPKM3 treatments,respectively,compared to NPK1 treatment.Grain yield was 86.1,93.1,93.6,and 96.5%higher under NPK1,NPKM1,NPKM2,and NPKM3 treatments,respectively,compared to NPK0 treatment.The NUE in NPKM1,NPKM2,and NPKM3 treatments was higher as compared to NPK1 treatment for both rice seasons.Redundancy analysis revealed close positive relationships of CSR with C input,total N,soil C:N ratio,catalase,and humic acids,whereas NUE was closely related to grain yield,grain N content,and phenol oxidase.Furthermore,CSR and NUE negatively correlated with humin acid and soil C:P and N:P ratios.The technique for order of preference by similarity to ideal solution(TOPSIS)showed that NPKM3 treatment was the optimum strategy for improving CSR and NUE.Therefore,substituting 70%of chemical fertilizer with organic manure could be the best management option for increasing CSR and NUE in the paddy fields of southern China.展开更多
The effects of substrate mingling ratio(SMR)(1:1,1:2,1:3,3:1,and 2:1)and organic loading rate(OLR)(50-90 g total solids per liter per day)on anaerobic co-digestion performance and microbial characteristics were invest...The effects of substrate mingling ratio(SMR)(1:1,1:2,1:3,3:1,and 2:1)and organic loading rate(OLR)(50-90 g total solids per liter per day)on anaerobic co-digestion performance and microbial characteristics were investigated for pig manure(PM)and pretreated/untreated corn stover in batch and semicontinuous anaerobic digestion(AD)system.The results showed that SMR and pretreatment affected co-digestion performance.The maximum cumulative methane yield of 428.5 ml·g^(-1)(based on volatile solids(VS))was obtained for PCP13,which was 35.7%and 40.0%higher than that of CSU and PM.In the first 5 days,the maximum methane yield improvement rate was 378.1%for PCP13.The daily methane yield per gram VS of PCP13 was 11.4%-18.5%higher than that of PC_(U)13.Clostridium_sensu_stricto_1,DMER64,and Bacteroides and Methanosaeta,Methanobacterium,and Methanospirillum had higher relative abundance at the genus level.Therefore,SMR and OLR are important factor affecting the AD process,and OLR can affect methane production through volatile fatty acids.展开更多
Phosphorus(P)is an essential nutrient for maize production,but in temperate areas the P uptake during early growing stages can be limited due to low soil temperature,even though the soil was tested high in P.The objec...Phosphorus(P)is an essential nutrient for maize production,but in temperate areas the P uptake during early growing stages can be limited due to low soil temperature,even though the soil was tested high in P.The objective of this study was to assess the effects of nitrogen and phosphorous(NP)starter fertilisation during early growth stages and its carryover until maize harvest,in mineral-fertilised or manured systems.A field experiment was carried out in north-west Italy during the 2019 and 2020 growing seasons.The trial compared sub-surface placement of NP(diammonium phosphate)or N alone(ammonium nitrate)in bands close to the maize seed furrows,in differing long-term(LT)fertilisation managements:two doses of urea(Min-L and Min-H),two doses of bovine slurry(Slu-L and Slu-H)or two doses of farmyard manure(Fym-L and Fym-H).The two rates,low(L)and high(H),corresponded to 170 and250 kg N ha^(-1)year^(-1) respectively.Compared to N fertilisation,NP starter fertilisation improved early maize growth assessed by leaf area index(LAI)and shoot dry weight(SDW)in all systems.The effects differed between the two years(2019:LAI+63%,SDW+67%;2020:LAI+36%,SDW+38%),as 2019was cool during the first growth.Higher LAI and SDW values were confirmed at crop flowering in the mineral-fertilised systems only.As shoot growth was enhanced by NP starter fertilisation,anthesis occurred 1 day earlier in all systems.However,a response to NP starter fertilisation at harvest was recorded in mineral-fertilised systems only(+1.3 and+3.2 t ha^(-1) in Min-L and Min-H,respectively).The uptake of P,used as a true indicator of soil nutrient availability,increased with increasing soil Olsen P until 39 mg kg^(-1).These results suggest that soil test thresholds should be revised for points above which P fertilisation should be suspended.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
The olive mill waste waters (OMWW) generated from olive oil extraction is a major environmental concern since they are characterized by their role as a pollutant (high organic and mineral matters) and their pH acid. T...The olive mill waste waters (OMWW) generated from olive oil extraction is a major environmental concern since they are characterized by their role as a pollutant (high organic and mineral matters) and their pH acid. The aim of this study was to valorize (OMWW) by anaerobic fermentation in the presence of cow manure in order to produce biogas and reduce their toxic load. Many tests were carried out by fermenting (OMWW) with polyphenols in the presence of cow manure in thermophile temperatures. The performance of this treatment was valuated through measurements of biogas production and by the determination of different parameters of fermented media (pH, volume of the biogas and polyphenols).展开更多
The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural productio...The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural production systems as alternative to synthetic elemental fertilizers has potential application to improve crop yield and fruit quality. A randomized complete block design (RCBD) was established to investigate the impact of nine soil treatments on yield and quality of bell pepper, Capsicum annuum and eggplant, Solanum melongena. The nine soil treatments included: chitin CH, biochar Bio, sewage sludge SS, chicken manure CM, SS mixed with biochar (SSBio), SS mixed with CH (SSCH), CM mixed with biochar (CMBio), CM mixed with CH (CMCH), and unamended (UN) native soil used as control treatment. At maturity, fruits from each treatment, were counted, weighed, and classified according to the USDA grades to U.S. Fancy, U.S. No.1, U.S. No.2, and culls. Overall number and weight of green pepper fruits collected from plants grown in SSCH were significantly greater (26.2 and 3.14 kg 5 plants<sup>-1</sup>) compared to fruits of plants grown in unamended control treatment (17.1 and 1.98 kg 5 Plants<sup>-1</sup>, respectively). Whereas CH alone was superior in increasing the number and weight of eggplant fruits compared to the control treatment. Average weight and number of eggplant fruits of plants grown in soil amended with chitin (4.46 kg and 11.5, respectively) were significantly (P ≤ 0.05) greater than weight and number of fruits obtained from plants grown in other soil treatments. Results also revealed a positive correlation coefficient (r) and high probability of significance (P) between number of fruits and weight of fruits among the nine soil treatments. Utilization of animal manures in agricultural systems is an inexpensive means for limited-resource farmers looking for improvements in crop yield and quality at affordable costs.展开更多
Pressure on land tenure is having a negative impact on the coconut sector, reducing farmers’ incomes. Intercropping cultivars plantain under coconut based has been considered as a solution to this problem. The aim of...Pressure on land tenure is having a negative impact on the coconut sector, reducing farmers’ incomes. Intercropping cultivars plantain under coconut based has been considered as a solution to this problem. The aim of this work is to diversify the sources of income for coconut growers. The plantain variety PITA 3, popularised by the CNRA, was grown in coconut inter-rows (PB113<sup>+</sup>), with two types of manure (chemical, organic). Six (06) treatments D1, D2, D3, D4, D5 and D6 were studied. In the tenth month after planting, treatment D3, which included banana plants fertilised with 9 kg of manure/plant, got the best agromorphological performance: height (264.08 cm), neck circumference (57.68 cm) and 12 leaves. In terms of production parameters, D3 banana plants had a shorter production cycle (347 days) and the highest diet mass (9.3 kg). However, the plants that received no fertiliser (D6) showed stunted growth and were unable to produce brunch. The fertilization of plantain with 10 t/ha of laying hen droppings permitted good development and production of plantains on tertiary sands.展开更多
To ensure food security, continuous intensive farming systems with limited fallowing periods and other farming systems like crop rotation have led to poor soil health with extremely low organic matter, especially in t...To ensure food security, continuous intensive farming systems with limited fallowing periods and other farming systems like crop rotation have led to poor soil health with extremely low organic matter, especially in tropical regions with high organic matter mineralization. Small-scale farmers in developing countries cannot afford intensive agricultural systems with heavy chemical inputs, which have not improved soil health. Inorganic fertilizers are harmful to the environment, so farmers should use cheap, locally available organic fertilizers like animal manure, which supports organic agricultural systems and soil health. Animal manure is used as a soil amendment to improve soil health, fertility, and crop yields, but data on how different manures affect specific crops is scarce. Poultry, cattle, and goat manure were compared to no fertilizer and mineral fertilizer on garden egg phenology, vegetative growth, and yield. Poultry manure improved garden egg vegetative growth, phenology, yield, and yield components compared to the negative control and the other treatments. Poultry manure yielded the most fruit at 0.921 kg∙ha<sup>-1</sup>, followed by cattle and goat manure at 0.709 kg∙ha<sup>-1</sup> and 0.698 kg∙ha<sup>-1</sup>. In conclusion, poultry manure may be a better alternative to synthetic NPK with yield performance similar to garden eggs and long-term soil health benefits similar to other manure sources.展开更多
Dissolved organic matter(DOM) plays important roles in soil biogeochemistry activity and nutrients transportation in soils, but studies regarding the long-term effects of green manures on the content and structure of ...Dissolved organic matter(DOM) plays important roles in soil biogeochemistry activity and nutrients transportation in soils, but studies regarding the long-term effects of green manures on the content and structure of DOM in red paddy soil have not been reported yet. A long-term green manure experiment established in 1982 was utilized to test the DOM contents in different treatments, and the spectral characteristics of DOM were investigated by using ultraviolet-visible(UV-Vis) spectrometry and Fourier transform infrared(FTIR) spectrometry. The experiment included four cropping systems: ricerice-milk vetch(RRV), rice-rice-rape(RRP), rice-rice-ryegrass(RRG) and rice-rice-winter fallow(RRF), among them, milk vetch, rape, and ryegrass are popular winter green manure species in southern China. The results showed that the content of dissolved organic carbon(DOC), which is widely used to estimate the concentration of DOM, was significantly promoted after the incorporation of green manures compared with the other sampling stages. The contents of aromatic groups and the degree of humification of DOM increased in RRV and RRP, suggesting more complex compositions of the soil DOM after long-term application of milk vetch and rape. The contents of phenol, alcohol and carboxylic acid group at the mature stage of early rice were significantly higher than those at the stage of after green manures turned over, especially for the RRV treatment. The absorption ratio of FTIR indicated that winter plantation of rape increased the aromatic-C/aliphatic-C ratio, and ryegrass increased the aromatic-C/carboxyl-C ratio. In conclusion, long-term planting of milk vetch and rape as green manures increased the degree of aromaticity, humification and average molecular weight of DOM, and made the DOM more stable in red paddy soil.展开更多
An enclosed chamber technique was used to measure N 2O emissions from intensively agricultural soils of the North China Plain during the periods of 1995—1996 and 1997—1998, to reflect distinct components of winter w...An enclosed chamber technique was used to measure N 2O emissions from intensively agricultural soils of the North China Plain during the periods of 1995—1996 and 1997—1998, to reflect distinct components of winter wheat and summer maize growing seasons. The results showed that the continuous application of fertilizer in agricultural soils increased N\-2O emissions by a factor of 24.1—28.1, the calculated annual chemical N fertilizer\|transformed N\-2O\|N emissions was 0.67%. Our results indicated that the application of organic manure also had a significant influence on soil N 2O emissions, which combined with the use of chemical N increased about 20% in a year. It was calculated that there were about 0.11% N of organic manure transformed as N 2O N. Annual mean N 2O emission from our study area of fertilized soils was estimated to be 57.1 μgN 2O/(m 2·h). A weak correlation was also found between N 2O emissions and soil available nitrogen content NH + 4.展开更多
This study investigated the carbon(C) and nitrogen(N) gas emissions(N_2O,NH_3,CO_2 and CH_4) from solid pig manure management in China.Gas emissions were quantified from static piles over 60 days during summer in Chin...This study investigated the carbon(C) and nitrogen(N) gas emissions(N_2O,NH_3,CO_2 and CH_4) from solid pig manure management in China.Gas emissions were quantified from static piles over 60 days during summer in China's Yangtze River Basin,using Drager-Tube and static chamber-gas chromatography techniques.High emissions of NH_3 and N_2 O were observed at the early stage of storage,but high emission of CH_4 occured later during storage.Overall,62% of the total C in the original pile was lost; CO_2 and CH_4 emissions accounted for 57 and 0.2% of C lost respectively.Over the same time,41% of the total N in the original pile was lost; NH_3 and N_2 O emissions accounted for 15 and 0.3% of N lost respectively.The volatilization of NH_3 during storage in summer was 4.56 g NH_3 per kg dry weight.The total greenhouse gas(GHG) emissions during storage accounted for 67.93 g CO_2 equivalent per kg dry weight; N_2 O and CH_4 contributed to 46 and 55% of total GHG emissions respectively.Given China's major role in pig production,further attention should given to pig manure management to mitigate its contribution to atmospheric pollution.展开更多
Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China.Safe disposal of the contained toxic pollution with animal manure by co-composti...Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China.Safe disposal of the contained toxic pollution with animal manure by co-composting with biochar is one of the alternative methods.Biochars from different sources(wheat straw,peanut shells and rice husks)amended with different loading rates were investigated for passivations of copper and zinc(Cu and Zn)in swine manure composting.Results showed that the passivation effects of the three types of biochar on Cu and Zn were enhanced with increasing biochar dose.Contents of Cu and Zn measured by diethylenetriaminepentaacetic acid(DTPA)and Community Bureau of Reference(CBR)showed that wheat straw biochar with the loading rates of 10%–13%(w/w)was superior to the other two types of biochar in this study.Compared with the control,sample from wheat straw biochar was more favorable for the bacterial growth of Proteobacteria,Firmicutes and Actinobacteria.In addition,pot experiment showed that organic fertilizer amended with wheat straw biochar could significantly improve the growth of Chinese pakchoi and enzyme activities(superoxide dismutase,peroxidase,polyphenol oxidase and catalase)as compared with the control.Cu and Zn contents of Chinese pakchoi in the organic fertilizer group containing wheat straw biochar reduced by 73.2%and 45.2%,65.8%and 33.6%,respectively,compared with the group without loading biochar.There was no significant difference in the contents of vitamin C and reducing sugar between the groups of organic fertilizer amended with/without wheat straw biochar,however,there was significant difference compared with the heavy metal addition group.The application of organic fertilizer formed by adding biochar can effectively reduce the adverse effects of heavy metals on crops.展开更多
Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformat...Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total N, soluble NH 4 N, soluble NO 3 N and soluble organic N. The total N increased after 63 days of composting, as well as the soluble NO 3 N and soluble organic N. Soluble NH 4 N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co composting of pig manure with sawdust reached maturity after 49 days of composting, while co composting of pig manure with sawdust and leaves required shorter time for 35 days. Soluble NH 4 N was significantly negatively ( P <0.05), while soluble NO 3 N and soluble organic N were significantly positively ( P <0.05), correlated with seed germination index (GI). Addition of leaves in co composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost.展开更多
The black soldier fly larvae(BSFL)(Hermetia illucens)are a good candidate for poultry and livestock manure treatment.The harvested insect bodies and feces can be used as animal feed and organic fertilizer.However,heav...The black soldier fly larvae(BSFL)(Hermetia illucens)are a good candidate for poultry and livestock manure treatment.The harvested insect bodies and feces can be used as animal feed and organic fertilizer.However,heavy metals have a negative impact on the transformation process of the manure by BSFL.Here we evaluated the effects of Cd,Cr and As in pig manure on the growth of BSFL,as well as the mobility and changes in speciation of the metals during the transformation process.The results showed that As significantly reduced the weight of BSFL,but Cr and Cd had no significant effects on BSFL growth.The bioaccumulation factors(BAFs)at various concentrations of Cd(2.8–3.7)were significantly higher than those of Cr(0.44–0.62)and As(0.43–0.45).The heavy metals in pig manure were mainly transferred to BSFL feces,and the distribution percentages of Cd,Cr and As in the BSFL feces were 52.6–62.0%,90.3–94.2%and 93.0–93.3%,respectively.Cd concentrations in BSFL feces were significantly lower than those in the pig manure,while there were no significant differences in the concentrations of Cr and As between BSFL feces and pig manure(except for the treatment with the addition of 150 mg Cr kg^(–1)).The metal speciation(weak acid soluble,reducible,oxidizable and residual fractions)in BSFL feces obviously changed when compared with pig manure.In BSFL feces,the reducible proportion of Cr decreased while the oxidizable proportion increased.Cd mainly existed in the weak acid soluble and reducible states in pig manure and BSFL feces.For As,the proportions of weak acid soluble and reducible states decreased in BSFL feces.After the BSFL transformation process,the bioavailable fraction of Cr decreased by 17.3–23.1%,but those of Cd and As did not change significantly,except for As in the CK group.These findings contribute to our understanding of the roles of BSFL during the biotransformation process of livestock manure as well as the safe utilization of transformed products.展开更多
Amaranthus cruentus is one of the sixty Amaranthus species of world. It is widely grown as a green leafy vegetable and for its grain in many tropical countries of Africa, Central and South American, Canada, Mexico and...Amaranthus cruentus is one of the sixty Amaranthus species of world. It is widely grown as a green leafy vegetable and for its grain in many tropical countries of Africa, Central and South American, Canada, Mexico and parts of Asia. Depleted soil fertility under intensive cultivation is a major limitation to production of the vegetable. The study investigated the effects of two types of poultry manure on biomass yield and nutrient uptake of Amaranth cruentus in a greenhouse at the University of Manitoba, Winnipeg, Manitoba, Canada in 2011. The experiment was a 2 × 3 × 3 factorial arranged into a Randomized Completely Block Design and replicated three times. The factors were two soil types, two sources of poultry manure and urea, and N rates at 0, 60 and 120 kg⋅N⋅ha−1. Nitrogen uptake by the plants that treated with poultry manure from Canada (PMC) and Urea was 172.5 vs. 171.4 mg⋅pot−1 and 169.5 vs. 163.7 mg⋅pot−1 respectively which were significantly greater than the poultry manure from Nigeria (PMN), 100.6 mg⋅pot−1 and 110.0 mg⋅pot−1 for Red River and Glenhope soil series, respectively. Nitrogen uptake was similar at the N rates of 60 and 120 kg⋅N⋅ha−1 (140.7 vs. 155.6 mg⋅pot−1) in the Red River soil, while N uptake at 120 kg⋅N⋅ha−1 was greater than at 60 kg⋅N⋅ha−1 in Glenhope soil. Shoot dry matter of the vegetable grown in soils treated with PMC and urea was significantly greater than from PMN in Red River soil (10.1, 9.6 and 6.7 g⋅pot−1) and in Glenhope soil (8.8, 8.1 and 6.4 g⋅pot−1). Phosphorus, K, Ca and Mg uptake at 60 and 120 kg⋅</展开更多
基金supported by the National Key Research and Development Program of China(2022YFD2301403-2)the Major Special Project of Anhui Province,China(2021d06050003)+2 种基金the Postdoctoral Foundation of Anhui Province,China(2022B638)the Special Project of Zhongke Bengbu Technology Transfer Center,China(ZKBB202103)the Grant of the President Foundation of Hefei Institutes of Physical Science of Chinese Academy of Sciences(YZJJ2023QN37)。
文摘Synthetic nitrogen(N)fertilizer has made a great contribution to the improvement of soil fertility and productivity,but excessive application of synthetic N fertilizer may cause agroecosystem risks,such as soil acidification,groundwater contamination and biodiversity reduction.Meanwhile,organic substitution has received increasing attention for its ecologically and environmentally friendly and productivity benefits.However,the linkages between manure substitution,crop yield and the underlying microbial mechanisms remain uncertain.To bridge this gap,a three-year field experiment was conducted with five fertilization regimes:i)Control,non-fertilization;CF,conventional synthetic fertilizer application;CF_(1/2)M_(1/2),1/2 N input via synthetic fertilizer and 1/2 N input via manure;CF_(1/4)M_(3/4),1/4 N input synthetic fertilizer and 3/4 N input via manure;M,manure application.All fertilization treatments were designed to have equal N input.Our results showed that all manure substituted treatments achieved high soil fertility indexes(SFI)and productivities by increasing the soil organic carbon(SOC),total N(TN)and available phosphorus(AP)concentrations,and by altering the bacterial community diversity and composition compared with CF.SOC,AP,and the soil C:N ratio were mainly responsible for microbial community variations.The co-occurrence network revealed that SOC and AP had strong positive associations with Rhodospirillales and Burkholderiales,while TN and C:N ratio had positive and negative associations with Micromonosporaceae,respectively.These specific taxa are implicated in soil macroelement turnover.Random Forest analysis predicted that both biotic(bacterial composition and Micromonosporaceae)and abiotic(AP,SOC,SFI,and TN)factors had significant effects on crop yield.The present work strengthens our understanding of the effects of manure substitution on crop yield and provides theoretical support for optimizing fertilization strategies.
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.
文摘Manure management is an essential component of dairy production. Nutrient-laden, field-applied dairy manure often serves as a fertilizer source, but can also pose environmental threats if not properly managed. The Haak dairy farm, located in Decatur, Arkansas, was granted a permit by the Arkansas Department of Environmental Quality (ADEQ) to employ a unique method in treating and storing cattle manure generated during the milking process. This method includes minimizing water use in wash water, dry scraping solids to combine with sawdust for composting and pumping effluent underground into a sloped concrete basin that serves as secondary solid separator before transporting the manure effluent into an interception trench and an adjacent grassed field to facilitate manure nutrient uptake and retention. The Arkansas Discovery Farm program (ADF) is conducting research to evaluate the environmental performance of the dairy’s milk center wash water treatment system (MCWW) by statistical analysis, characterization of phosphorus (P) migration in soil downslope from the inception trench, temperature measurements, and nutrient analysis of a stored dry stack manure/sawdust mixture. Goals included determining possible composting effectiveness along with comparisons to untreated dairy manure and quantifying the use of on-farm water. Results from this research demonstrated that: 1) The MCWW was effective at retaining manure-derived nutrients and reducing field nutrient migration as the MCWW interception trench had significantly higher total nitrogen (TN) (804.2 to 4.1), total phosphorus (TP) (135.6 to 1.5), and water extractable phosphorus (WEP) (55.0 to 1.0) concentrations in milligrams per liter (mg⋅L<sup>-1</sup>) than the downhill freshwater pond respectively;2) temperature readings of the manure dry stack indicated heightened levels of microbial and thermal activity, but did not reach a standard composting temperature of 54°C;3) manure dry stack nutrient content was typically higher than untreated dairy manure when measured on a “dry basis” in ppm, but was lower on an “as is basis” in ppm and kg/metric ton;and 4) water meter readings showed that the greatest use of on-farm water was for farm-wide cattle drinking (18.77), followed by water used in the milking center (3.45) and then followed by human usage (0.02) measured in cubic meters per day (m<sup>3</sup>⋅d<sup>-1</sup>). These results demonstrate that practical innovations in agricultural engineering and environmental science, such as the Haak dairy’s manure treatment system, can effectively reduce environmental hazards that accompany the management of manure at this dairy operation.
基金supported by the National Natural Science Foundation of China (41671301)the National Key Research and Development Program of China (2016YFD0300901)the Central Public-interest Scientific Institution Basal Research Fund, China (GY2022-13-5, G2022-02-2, G2022-02-3 and G2022-02-10)
文摘Combined application of chemical fertilizers with organic amendments was recommended as a strategy for improving yield,soil carbon storage,and nutrient use efficiency.However,how the long-term substitution of chemical fertilizer with organic manure affects rice yield,carbon sequestration rate(CSR),and nitrogen use efficiency(NUE)while ensuring environmental safety remains unclear.This study assessed the long-term effect of substituting chemical fertilizer with organic manure on rice yield,CSR,and NUE.It also determined the optimum substitution ratio in the acidic soil of southern China.The treatments were:(i)NPK0,unfertilized control;(ii)NPK1,100%chemical nitrogen,phosphorus,and potassium fertilizer;(iii)NPKM1,70%chemical NPK fertilizer and 30%organic manure;(iv)NPKM2,50%chemical NPK fertilizer and 50%organic manure;and(v)NPKM3,30%chemical NPK fertilizer and 70%organic manure.Milk vetch and pig manure were sources of manure for early and late rice seasons,respectively.The result showed that SOC content was higher in NPKM1,NPKM2,and NPKM3 treatments than in NPK0 and NPK1 treatments.The carbon sequestration rate increased by 140,160,and 280%under NPKM1,NPKM2,and NPKM3 treatments,respectively,compared to NPK1 treatment.Grain yield was 86.1,93.1,93.6,and 96.5%higher under NPK1,NPKM1,NPKM2,and NPKM3 treatments,respectively,compared to NPK0 treatment.The NUE in NPKM1,NPKM2,and NPKM3 treatments was higher as compared to NPK1 treatment for both rice seasons.Redundancy analysis revealed close positive relationships of CSR with C input,total N,soil C:N ratio,catalase,and humic acids,whereas NUE was closely related to grain yield,grain N content,and phenol oxidase.Furthermore,CSR and NUE negatively correlated with humin acid and soil C:P and N:P ratios.The technique for order of preference by similarity to ideal solution(TOPSIS)showed that NPKM3 treatment was the optimum strategy for improving CSR and NUE.Therefore,substituting 70%of chemical fertilizer with organic manure could be the best management option for increasing CSR and NUE in the paddy fields of southern China.
基金the fund supports from the Fundamental Research Funds for the Central Universities(JD2326).
文摘The effects of substrate mingling ratio(SMR)(1:1,1:2,1:3,3:1,and 2:1)and organic loading rate(OLR)(50-90 g total solids per liter per day)on anaerobic co-digestion performance and microbial characteristics were investigated for pig manure(PM)and pretreated/untreated corn stover in batch and semicontinuous anaerobic digestion(AD)system.The results showed that SMR and pretreatment affected co-digestion performance.The maximum cumulative methane yield of 428.5 ml·g^(-1)(based on volatile solids(VS))was obtained for PCP13,which was 35.7%and 40.0%higher than that of CSU and PM.In the first 5 days,the maximum methane yield improvement rate was 378.1%for PCP13.The daily methane yield per gram VS of PCP13 was 11.4%-18.5%higher than that of PC_(U)13.Clostridium_sensu_stricto_1,DMER64,and Bacteroides and Methanosaeta,Methanobacterium,and Methanospirillum had higher relative abundance at the genus level.Therefore,SMR and OLR are important factor affecting the AD process,and OLR can affect methane production through volatile fatty acids.
基金the financial support of the Regione Piemonte(Italy)。
文摘Phosphorus(P)is an essential nutrient for maize production,but in temperate areas the P uptake during early growing stages can be limited due to low soil temperature,even though the soil was tested high in P.The objective of this study was to assess the effects of nitrogen and phosphorous(NP)starter fertilisation during early growth stages and its carryover until maize harvest,in mineral-fertilised or manured systems.A field experiment was carried out in north-west Italy during the 2019 and 2020 growing seasons.The trial compared sub-surface placement of NP(diammonium phosphate)or N alone(ammonium nitrate)in bands close to the maize seed furrows,in differing long-term(LT)fertilisation managements:two doses of urea(Min-L and Min-H),two doses of bovine slurry(Slu-L and Slu-H)or two doses of farmyard manure(Fym-L and Fym-H).The two rates,low(L)and high(H),corresponded to 170 and250 kg N ha^(-1)year^(-1) respectively.Compared to N fertilisation,NP starter fertilisation improved early maize growth assessed by leaf area index(LAI)and shoot dry weight(SDW)in all systems.The effects differed between the two years(2019:LAI+63%,SDW+67%;2020:LAI+36%,SDW+38%),as 2019was cool during the first growth.Higher LAI and SDW values were confirmed at crop flowering in the mineral-fertilised systems only.As shoot growth was enhanced by NP starter fertilisation,anthesis occurred 1 day earlier in all systems.However,a response to NP starter fertilisation at harvest was recorded in mineral-fertilised systems only(+1.3 and+3.2 t ha^(-1) in Min-L and Min-H,respectively).The uptake of P,used as a true indicator of soil nutrient availability,increased with increasing soil Olsen P until 39 mg kg^(-1).These results suggest that soil test thresholds should be revised for points above which P fertilisation should be suspended.
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.
文摘The olive mill waste waters (OMWW) generated from olive oil extraction is a major environmental concern since they are characterized by their role as a pollutant (high organic and mineral matters) and their pH acid. The aim of this study was to valorize (OMWW) by anaerobic fermentation in the presence of cow manure in order to produce biogas and reduce their toxic load. Many tests were carried out by fermenting (OMWW) with polyphenols in the presence of cow manure in thermophile temperatures. The performance of this treatment was valuated through measurements of biogas production and by the determination of different parameters of fermented media (pH, volume of the biogas and polyphenols).
文摘The global obligation for food requires soil and plant management practices that provide valuable effects on the physical, chemical, and organic properties of soils. The use of animal manure, in agricultural production systems as alternative to synthetic elemental fertilizers has potential application to improve crop yield and fruit quality. A randomized complete block design (RCBD) was established to investigate the impact of nine soil treatments on yield and quality of bell pepper, Capsicum annuum and eggplant, Solanum melongena. The nine soil treatments included: chitin CH, biochar Bio, sewage sludge SS, chicken manure CM, SS mixed with biochar (SSBio), SS mixed with CH (SSCH), CM mixed with biochar (CMBio), CM mixed with CH (CMCH), and unamended (UN) native soil used as control treatment. At maturity, fruits from each treatment, were counted, weighed, and classified according to the USDA grades to U.S. Fancy, U.S. No.1, U.S. No.2, and culls. Overall number and weight of green pepper fruits collected from plants grown in SSCH were significantly greater (26.2 and 3.14 kg 5 plants<sup>-1</sup>) compared to fruits of plants grown in unamended control treatment (17.1 and 1.98 kg 5 Plants<sup>-1</sup>, respectively). Whereas CH alone was superior in increasing the number and weight of eggplant fruits compared to the control treatment. Average weight and number of eggplant fruits of plants grown in soil amended with chitin (4.46 kg and 11.5, respectively) were significantly (P ≤ 0.05) greater than weight and number of fruits obtained from plants grown in other soil treatments. Results also revealed a positive correlation coefficient (r) and high probability of significance (P) between number of fruits and weight of fruits among the nine soil treatments. Utilization of animal manures in agricultural systems is an inexpensive means for limited-resource farmers looking for improvements in crop yield and quality at affordable costs.
文摘Pressure on land tenure is having a negative impact on the coconut sector, reducing farmers’ incomes. Intercropping cultivars plantain under coconut based has been considered as a solution to this problem. The aim of this work is to diversify the sources of income for coconut growers. The plantain variety PITA 3, popularised by the CNRA, was grown in coconut inter-rows (PB113<sup>+</sup>), with two types of manure (chemical, organic). Six (06) treatments D1, D2, D3, D4, D5 and D6 were studied. In the tenth month after planting, treatment D3, which included banana plants fertilised with 9 kg of manure/plant, got the best agromorphological performance: height (264.08 cm), neck circumference (57.68 cm) and 12 leaves. In terms of production parameters, D3 banana plants had a shorter production cycle (347 days) and the highest diet mass (9.3 kg). However, the plants that received no fertiliser (D6) showed stunted growth and were unable to produce brunch. The fertilization of plantain with 10 t/ha of laying hen droppings permitted good development and production of plantains on tertiary sands.
文摘To ensure food security, continuous intensive farming systems with limited fallowing periods and other farming systems like crop rotation have led to poor soil health with extremely low organic matter, especially in tropical regions with high organic matter mineralization. Small-scale farmers in developing countries cannot afford intensive agricultural systems with heavy chemical inputs, which have not improved soil health. Inorganic fertilizers are harmful to the environment, so farmers should use cheap, locally available organic fertilizers like animal manure, which supports organic agricultural systems and soil health. Animal manure is used as a soil amendment to improve soil health, fertility, and crop yields, but data on how different manures affect specific crops is scarce. Poultry, cattle, and goat manure were compared to no fertilizer and mineral fertilizer on garden egg phenology, vegetative growth, and yield. Poultry manure improved garden egg vegetative growth, phenology, yield, and yield components compared to the negative control and the other treatments. Poultry manure yielded the most fruit at 0.921 kg∙ha<sup>-1</sup>, followed by cattle and goat manure at 0.709 kg∙ha<sup>-1</sup> and 0.698 kg∙ha<sup>-1</sup>. In conclusion, poultry manure may be a better alternative to synthetic NPK with yield performance similar to garden eggs and long-term soil health benefits similar to other manure sources.
基金supported by the earmarked fund for China Agriculture Research System (2013–2017)the Chinese Outstanding Talents Program in Agricultural Sciences
文摘Dissolved organic matter(DOM) plays important roles in soil biogeochemistry activity and nutrients transportation in soils, but studies regarding the long-term effects of green manures on the content and structure of DOM in red paddy soil have not been reported yet. A long-term green manure experiment established in 1982 was utilized to test the DOM contents in different treatments, and the spectral characteristics of DOM were investigated by using ultraviolet-visible(UV-Vis) spectrometry and Fourier transform infrared(FTIR) spectrometry. The experiment included four cropping systems: ricerice-milk vetch(RRV), rice-rice-rape(RRP), rice-rice-ryegrass(RRG) and rice-rice-winter fallow(RRF), among them, milk vetch, rape, and ryegrass are popular winter green manure species in southern China. The results showed that the content of dissolved organic carbon(DOC), which is widely used to estimate the concentration of DOM, was significantly promoted after the incorporation of green manures compared with the other sampling stages. The contents of aromatic groups and the degree of humification of DOM increased in RRV and RRP, suggesting more complex compositions of the soil DOM after long-term application of milk vetch and rape. The contents of phenol, alcohol and carboxylic acid group at the mature stage of early rice were significantly higher than those at the stage of after green manures turned over, especially for the RRV treatment. The absorption ratio of FTIR indicated that winter plantation of rape increased the aromatic-C/aliphatic-C ratio, and ryegrass increased the aromatic-C/carboxyl-C ratio. In conclusion, long-term planting of milk vetch and rape as green manures increased the degree of aromaticity, humification and average molecular weight of DOM, and made the DOM more stable in red paddy soil.
基金TheNationalNaturalScienceFoundationofChina (No .496 710 0 4) TheDirectorFoundationofInstituteofGeographicSciencesandNaturalRe
文摘An enclosed chamber technique was used to measure N 2O emissions from intensively agricultural soils of the North China Plain during the periods of 1995—1996 and 1997—1998, to reflect distinct components of winter wheat and summer maize growing seasons. The results showed that the continuous application of fertilizer in agricultural soils increased N\-2O emissions by a factor of 24.1—28.1, the calculated annual chemical N fertilizer\|transformed N\-2O\|N emissions was 0.67%. Our results indicated that the application of organic manure also had a significant influence on soil N 2O emissions, which combined with the use of chemical N increased about 20% in a year. It was calculated that there were about 0.11% N of organic manure transformed as N 2O N. Annual mean N 2O emission from our study area of fertilized soils was estimated to be 57.1 μgN 2O/(m 2·h). A weak correlation was also found between N 2O emissions and soil available nitrogen content NH + 4.
基金supported by the National Key Research and Development Program of China (2016YFE0101100,2016YFD0201204,2017YFD0201801)the National Natural Science Foundation of China (41671303)+3 种基金the Fund amental Research Funds for Central Non-profit Scientific Institution of China (1610132016042)the Agro-scientific Research in the Public Interest of China (201303103)the National Basic Research Program of China (973 Program,2012CB417100)the Australia-China Joint Research Centre-Healthy Soils for Sustainable Food Production and Environmental Quality jointly funded by the Australian Department of Industry,Innovation and Science (ACSRF48165)
文摘This study investigated the carbon(C) and nitrogen(N) gas emissions(N_2O,NH_3,CO_2 and CH_4) from solid pig manure management in China.Gas emissions were quantified from static piles over 60 days during summer in China's Yangtze River Basin,using Drager-Tube and static chamber-gas chromatography techniques.High emissions of NH_3 and N_2 O were observed at the early stage of storage,but high emission of CH_4 occured later during storage.Overall,62% of the total C in the original pile was lost; CO_2 and CH_4 emissions accounted for 57 and 0.2% of C lost respectively.Over the same time,41% of the total N in the original pile was lost; NH_3 and N_2 O emissions accounted for 15 and 0.3% of N lost respectively.The volatilization of NH_3 during storage in summer was 4.56 g NH_3 per kg dry weight.The total greenhouse gas(GHG) emissions during storage accounted for 67.93 g CO_2 equivalent per kg dry weight; N_2 O and CH_4 contributed to 46 and 55% of total GHG emissions respectively.Given China's major role in pig production,further attention should given to pig manure management to mitigate its contribution to atmospheric pollution.
基金the National Natural Science Foundation of China(41861124004)the China Postdoctoral Science Foundation(2017M613260)the National Key Research and Development Program of China(2016YFD0501406).
文摘Pollution of arable land caused by heavy metals in livestock and poultry manure has become a potential threaten to human health in China.Safe disposal of the contained toxic pollution with animal manure by co-composting with biochar is one of the alternative methods.Biochars from different sources(wheat straw,peanut shells and rice husks)amended with different loading rates were investigated for passivations of copper and zinc(Cu and Zn)in swine manure composting.Results showed that the passivation effects of the three types of biochar on Cu and Zn were enhanced with increasing biochar dose.Contents of Cu and Zn measured by diethylenetriaminepentaacetic acid(DTPA)and Community Bureau of Reference(CBR)showed that wheat straw biochar with the loading rates of 10%–13%(w/w)was superior to the other two types of biochar in this study.Compared with the control,sample from wheat straw biochar was more favorable for the bacterial growth of Proteobacteria,Firmicutes and Actinobacteria.In addition,pot experiment showed that organic fertilizer amended with wheat straw biochar could significantly improve the growth of Chinese pakchoi and enzyme activities(superoxide dismutase,peroxidase,polyphenol oxidase and catalase)as compared with the control.Cu and Zn contents of Chinese pakchoi in the organic fertilizer group containing wheat straw biochar reduced by 73.2%and 45.2%,65.8%and 33.6%,respectively,compared with the group without loading biochar.There was no significant difference in the contents of vitamin C and reducing sugar between the groups of organic fertilizer amended with/without wheat straw biochar,however,there was significant difference compared with the heavy metal addition group.The application of organic fertilizer formed by adding biochar can effectively reduce the adverse effects of heavy metals on crops.
文摘Composting is now suggested as one of the environmentally and friendly alternative method for disposal of solid organic wastes, as it leads to minimization, stabilization, and utilization of organic waste. Transformations of nitrogen were investigated in co composting of pig manure with different amendments, such as sawdust and leaves. Samples were analyzed for pH, total N, soluble NH 4 N, soluble NO 3 N and soluble organic N. The total N increased after 63 days of composting, as well as the soluble NO 3 N and soluble organic N. Soluble NH 4 N increased significantly and showed peak values at day 7, thereafter decreased sharply and gradually to lower levels. Seed germination index (GI) showed that co composting of pig manure with sawdust reached maturity after 49 days of composting, while co composting of pig manure with sawdust and leaves required shorter time for 35 days. Soluble NH 4 N was significantly negatively ( P <0.05), while soluble NO 3 N and soluble organic N were significantly positively ( P <0.05), correlated with seed germination index (GI). Addition of leaves in co composting of pig manure with sawdust had no significant impacts on nitrogen transformations, but it was beneficial for maturity of pig manure compost.
基金the National Key Research and Development Program of China(2018YFD0500205)the Tianjin Science and Technology Plan Project,China(19ZYYFSN00010 and 18ZXYENC00130)the National Natural Science Foundation of China(21607114)。
文摘The black soldier fly larvae(BSFL)(Hermetia illucens)are a good candidate for poultry and livestock manure treatment.The harvested insect bodies and feces can be used as animal feed and organic fertilizer.However,heavy metals have a negative impact on the transformation process of the manure by BSFL.Here we evaluated the effects of Cd,Cr and As in pig manure on the growth of BSFL,as well as the mobility and changes in speciation of the metals during the transformation process.The results showed that As significantly reduced the weight of BSFL,but Cr and Cd had no significant effects on BSFL growth.The bioaccumulation factors(BAFs)at various concentrations of Cd(2.8–3.7)were significantly higher than those of Cr(0.44–0.62)and As(0.43–0.45).The heavy metals in pig manure were mainly transferred to BSFL feces,and the distribution percentages of Cd,Cr and As in the BSFL feces were 52.6–62.0%,90.3–94.2%and 93.0–93.3%,respectively.Cd concentrations in BSFL feces were significantly lower than those in the pig manure,while there were no significant differences in the concentrations of Cr and As between BSFL feces and pig manure(except for the treatment with the addition of 150 mg Cr kg^(–1)).The metal speciation(weak acid soluble,reducible,oxidizable and residual fractions)in BSFL feces obviously changed when compared with pig manure.In BSFL feces,the reducible proportion of Cr decreased while the oxidizable proportion increased.Cd mainly existed in the weak acid soluble and reducible states in pig manure and BSFL feces.For As,the proportions of weak acid soluble and reducible states decreased in BSFL feces.After the BSFL transformation process,the bioavailable fraction of Cr decreased by 17.3–23.1%,but those of Cd and As did not change significantly,except for As in the CK group.These findings contribute to our understanding of the roles of BSFL during the biotransformation process of livestock manure as well as the safe utilization of transformed products.
文摘Amaranthus cruentus is one of the sixty Amaranthus species of world. It is widely grown as a green leafy vegetable and for its grain in many tropical countries of Africa, Central and South American, Canada, Mexico and parts of Asia. Depleted soil fertility under intensive cultivation is a major limitation to production of the vegetable. The study investigated the effects of two types of poultry manure on biomass yield and nutrient uptake of Amaranth cruentus in a greenhouse at the University of Manitoba, Winnipeg, Manitoba, Canada in 2011. The experiment was a 2 × 3 × 3 factorial arranged into a Randomized Completely Block Design and replicated three times. The factors were two soil types, two sources of poultry manure and urea, and N rates at 0, 60 and 120 kg⋅N⋅ha−1. Nitrogen uptake by the plants that treated with poultry manure from Canada (PMC) and Urea was 172.5 vs. 171.4 mg⋅pot−1 and 169.5 vs. 163.7 mg⋅pot−1 respectively which were significantly greater than the poultry manure from Nigeria (PMN), 100.6 mg⋅pot−1 and 110.0 mg⋅pot−1 for Red River and Glenhope soil series, respectively. Nitrogen uptake was similar at the N rates of 60 and 120 kg⋅N⋅ha−1 (140.7 vs. 155.6 mg⋅pot−1) in the Red River soil, while N uptake at 120 kg⋅N⋅ha−1 was greater than at 60 kg⋅N⋅ha−1 in Glenhope soil. Shoot dry matter of the vegetable grown in soils treated with PMC and urea was significantly greater than from PMN in Red River soil (10.1, 9.6 and 6.7 g⋅pot−1) and in Glenhope soil (8.8, 8.1 and 6.4 g⋅pot−1). Phosphorus, K, Ca and Mg uptake at 60 and 120 kg⋅</
