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
The study was conducted to reveal P fractions and N forms changing characters during composting of pig manure with rice straw.During composting,the NH 4 +-N concentration decreased and reached at a relatively low va...The study was conducted to reveal P fractions and N forms changing characters during composting of pig manure with rice straw.During composting,the NH 4 +-N concentration decreased and reached at a relatively low value(〈400 mg kg-1) in the final compost,while the NO 3--N concentration increased.Total N losses mainly occurred during thermophilic phase due to the high temperature,the high NH 4 +-N concentration and the increase of pH value.Labile inorganic P was dominated in the pig manure and initial compost mixture.During composting,the proportion of labile inorganic P of total extracted P decreased,while the proportion of Fe+Al-bound P,Ca+Mg-bound P and residual P increased.The evolutions of the proportion of labile inorganic P,Fe+Al-bound P and Ca+Mg-bound P were well correlated with the changes of pH value,organic matter and C/N ratio.Therefore,composting could increase the concentration of N and P and decrease the presence of NH 4 +-N and labile P fractions which might cause environmental issues following land application.展开更多
Organic amendment is considered as an effective way to increase soil organic carbon (SOC) stock in croplands. To better understand its potential for SOC sequestration, whether SOC saturation could be observed in an ...Organic amendment is considered as an effective way to increase soil organic carbon (SOC) stock in croplands. To better understand its potential for SOC sequestration, whether SOC saturation could be observed in an intensive agricultural ecosystem receiving long-term composted manure were examined. Different SOC pools were isolated by physical fractionation techniques ofa Cambisol soil under a long-term manure experiment with wheat-maize cropping in North China Plain. A field experiment was initiated in 1993, with 6 treatments including control (i.e., without fertilization), chemical fertilizer only, low rate of traditional composted manure (7.5 t ha-h), high rate of traditional composted manure (15 t ha-~), low rate ofbio-composted manure (7.5 t ha-h) and high rate of bio-composted manure (15 t ha-h). The results showed that consecutive (for up to 20 years) composted manure amendments significantly improved soil macro-aggregation, aggregate associated SOC concentration, and soil structure stability. In detail, SOC concentration in the sand-sized fraction (〉53 ~tm) continued to increase with manure application rate, while the silt (2-53 I.tm) and clay (〈2 ~tm) particles showed no further increase with greater C inputs, exhibiting the C saturation. Further physical separation of small macro-aggregates (250-2 000 tam) into subpools showed that the non-protected coarse particulate organic matter (cPOM, 〉250 pro) was the fraction in which SOC continued to increase with increasing manure application rate. In contrast, the chemical and physical protected C pools (i.e., micro-aggregates and silt-clay occluded in the small macro- aggregates) exhibited no additional C sequestration when the manure application rate was increased. It can be concluded that repeated manure amendments can increase soil macro-aggregation and lead to the increase in relatively stable C pools, showing hierarchical saturation behavior in the intensive cropping system of North China Plain.展开更多
[ Objective] The aim of this study was to develop a cheap and localized microbial agent so as to solve high cost of microbial agent for pig manure composting in Jiaxing City. [ Method] Pig manure in the experimental g...[ Objective] The aim of this study was to develop a cheap and localized microbial agent so as to solve high cost of microbial agent for pig manure composting in Jiaxing City. [ Method] Pig manure in the experimental group and control group was inoculated with the self-developed micro- bial agent and commercial microbial agent, respectively. The manure was decomposed for 38 d, during which the indicators of compost including physical properties, temperature, pH value, water content, organic matter, dissolved nitrogen, carbon nitrogen ratio and germination rate were studied. [ Result] The water content in the experimental group declined to 26.10% after 33 d of compost, meeting the standard upper limitation of 30% for maturity. By comparison, the water content in the control group was slightly higher than 30% even after 38 d. The germination rate of seeds fertilized with the experimental manure compost met the standard for maturity on Day 28, while that in the control group met the standard for maturity on Day 35. When the composting was finished, the ratio of total carbon to total nitrogen in the pig manure was 14.64 and 16.43 respective- ly in the experimental and control group, and the organic matter content was about 45% for both. All these indexes could meet the standards for or- ganic fertilizer products. [ Conclusion] The self-developed microbial agent can moot the requirements for pig manure composting, and it can shorten the composting time by 5 -8 d compared with the commercial agent. In addition, the fertilizer product composted by the self-developed microbial a qent has lower water content and thereby is much more beneficial for preservation.展开更多
The addition of biochar could mitigate the bioavailability of heavy metals during livestock manure composting.However,the main action mechanism of biochar,such as how it worked,was ambiguous.Therefore,in this study,ma...The addition of biochar could mitigate the bioavailability of heavy metals during livestock manure composting.However,the main action mechanism of biochar,such as how it worked,was ambiguous.Therefore,in this study,materials(biochar,alkali modified biochar,pretreated cotton ball)were added by embedding with nylon mesh bags to explore the adsorption performance of added materials and its influence on the composting process.The results showed that embedded materials promoted the formation of humic acid and reduced the distribution proportion of bioavailable fraction of heavy metals during composting(Cu:at least 15.72%;Zn:at least 33.44%).The surface of biochar extracted from composting contained attachments,however,the attachment of heavy metal was not detected and functional groups on the materials did no change significantly.This indicated that the addition of biochar did not directly adsorb heavy metals.Most notably,the microbial network changed after embedding materials,and the succession of microbial community promoted the formation of humic acid.Ultimately,structural equation models verified that embedded materials promoted the formation of humic acid through stable microbial groups,thereby accelerating the passivation of heavy metals during composting.This study provides theoretical and technical supports for mitigating the biotoxicity of heavy metals by biochar during composting.展开更多
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 Major Science and Technology Program for Water Pollution Control and Treatment (2012ZX07201004)Jilin Provincial Research Foundation for Basic Research, China (201105033)
文摘The study was conducted to reveal P fractions and N forms changing characters during composting of pig manure with rice straw.During composting,the NH 4 +-N concentration decreased and reached at a relatively low value(〈400 mg kg-1) in the final compost,while the NO 3--N concentration increased.Total N losses mainly occurred during thermophilic phase due to the high temperature,the high NH 4 +-N concentration and the increase of pH value.Labile inorganic P was dominated in the pig manure and initial compost mixture.During composting,the proportion of labile inorganic P of total extracted P decreased,while the proportion of Fe+Al-bound P,Ca+Mg-bound P and residual P increased.The evolutions of the proportion of labile inorganic P,Fe+Al-bound P and Ca+Mg-bound P were well correlated with the changes of pH value,organic matter and C/N ratio.Therefore,composting could increase the concentration of N and P and decrease the presence of NH 4 +-N and labile P fractions which might cause environmental issues following land application.
基金funded by the National Natural Science Foundation of China(31261140367,31170489 and 30870414)the China Postdoctoral Science Foundation(201104164 and 20100470408)the S&T Innovation Program of Chinese Academy of Agricultural Sciences
文摘Organic amendment is considered as an effective way to increase soil organic carbon (SOC) stock in croplands. To better understand its potential for SOC sequestration, whether SOC saturation could be observed in an intensive agricultural ecosystem receiving long-term composted manure were examined. Different SOC pools were isolated by physical fractionation techniques ofa Cambisol soil under a long-term manure experiment with wheat-maize cropping in North China Plain. A field experiment was initiated in 1993, with 6 treatments including control (i.e., without fertilization), chemical fertilizer only, low rate of traditional composted manure (7.5 t ha-h), high rate of traditional composted manure (15 t ha-~), low rate ofbio-composted manure (7.5 t ha-h) and high rate of bio-composted manure (15 t ha-h). The results showed that consecutive (for up to 20 years) composted manure amendments significantly improved soil macro-aggregation, aggregate associated SOC concentration, and soil structure stability. In detail, SOC concentration in the sand-sized fraction (〉53 ~tm) continued to increase with manure application rate, while the silt (2-53 I.tm) and clay (〈2 ~tm) particles showed no further increase with greater C inputs, exhibiting the C saturation. Further physical separation of small macro-aggregates (250-2 000 tam) into subpools showed that the non-protected coarse particulate organic matter (cPOM, 〉250 pro) was the fraction in which SOC continued to increase with increasing manure application rate. In contrast, the chemical and physical protected C pools (i.e., micro-aggregates and silt-clay occluded in the small macro- aggregates) exhibited no additional C sequestration when the manure application rate was increased. It can be concluded that repeated manure amendments can increase soil macro-aggregation and lead to the increase in relatively stable C pools, showing hierarchical saturation behavior in the intensive cropping system of North China Plain.
基金funded by the Science and Technology Project of Nanhu District,Jiaxing City,Zhejiang Province
文摘[ Objective] The aim of this study was to develop a cheap and localized microbial agent so as to solve high cost of microbial agent for pig manure composting in Jiaxing City. [ Method] Pig manure in the experimental group and control group was inoculated with the self-developed micro- bial agent and commercial microbial agent, respectively. The manure was decomposed for 38 d, during which the indicators of compost including physical properties, temperature, pH value, water content, organic matter, dissolved nitrogen, carbon nitrogen ratio and germination rate were studied. [ Result] The water content in the experimental group declined to 26.10% after 33 d of compost, meeting the standard upper limitation of 30% for maturity. By comparison, the water content in the control group was slightly higher than 30% even after 38 d. The germination rate of seeds fertilized with the experimental manure compost met the standard for maturity on Day 28, while that in the control group met the standard for maturity on Day 35. When the composting was finished, the ratio of total carbon to total nitrogen in the pig manure was 14.64 and 16.43 respective- ly in the experimental and control group, and the organic matter content was about 45% for both. All these indexes could meet the standards for or- ganic fertilizer products. [ Conclusion] The self-developed microbial agent can moot the requirements for pig manure composting, and it can shorten the composting time by 5 -8 d compared with the commercial agent. In addition, the fertilizer product composted by the self-developed microbial a qent has lower water content and thereby is much more beneficial for preservation.
基金the National Natural Science Foundation of China[Grant Numbers:51878132 and 51978131]National Key Research and Development Project[Grant Number:2019YFC1906403].
文摘The addition of biochar could mitigate the bioavailability of heavy metals during livestock manure composting.However,the main action mechanism of biochar,such as how it worked,was ambiguous.Therefore,in this study,materials(biochar,alkali modified biochar,pretreated cotton ball)were added by embedding with nylon mesh bags to explore the adsorption performance of added materials and its influence on the composting process.The results showed that embedded materials promoted the formation of humic acid and reduced the distribution proportion of bioavailable fraction of heavy metals during composting(Cu:at least 15.72%;Zn:at least 33.44%).The surface of biochar extracted from composting contained attachments,however,the attachment of heavy metal was not detected and functional groups on the materials did no change significantly.This indicated that the addition of biochar did not directly adsorb heavy metals.Most notably,the microbial network changed after embedding materials,and the succession of microbial community promoted the formation of humic acid.Ultimately,structural equation models verified that embedded materials promoted the formation of humic acid through stable microbial groups,thereby accelerating the passivation of heavy metals during composting.This study provides theoretical and technical supports for mitigating the biotoxicity of heavy metals by biochar during composting.