Effect of four crop straws on transformation of organic matter during sewage sludge composting

A 45-d laboratory experiment was conducted to compare the effect of four crop straws on the transformations of organic matter （OM） during composting of sewage sludge. The four crop straws included rape straw, wheat straw, maize straw and rice straw. The following parameters such as temperature, OM, humic-like substances （HS）, fulvic-like acids （FA） and humic-like acids （HA） were determined. The degradation of OM and the formation of HS and HA could be described well by the first-order kinetic model, while the FA content fluctuated during composting. The maximal degradation rates of OM in the compost piles added with rape straw, wheat straw, maize straw and rice straw were 34.7, 46.9, 54.7 and 52.8%, respectively, and the final contents of HS were 118, 128, 141 and 134 g kg-1, respectively, while the humification indices were higher in the compost piles added with maize straw and wheat straw than in those with rice straw and rape straw. The results indicate that a higher hemicellulose content and a lower C/N ratio in crop straw can result in a higher rate of OM degradation and higher contents of HS, while a higher content of lignin can lead to a higher polymerization degree of humic substances in compost piles. The final compost piles added with maize straw has the highest contents of OM, total nitrogen and humus substance as well as the highest values of polymerization degree, while compost piles with rape straw have the highest potassium content and those with rice straw have the highest pH values.

Changes in Phosphorus Fractions and Nitrogen Forms During Composting of Pig Manure with Rice Straw

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.

Screening of Fermentation Starters for Organic Fertilizer Composted from Chicken Manure

In order to find fermentation starters that can promote rapid and effective composting of chicken manure,shorten the fermentation period,and improve the compost quality,fermentation starters with different microbial combination ratios(C1,C2,C3,C4 and C5) were designed and fermentation experiment was carried out on these five fermentation starters,commercially available organic fertilizer starter(SS),and chicken manure without inoculating fermentation starter. In the process of the fermentation,the changes in the fermentation temperature,water content and pH value were monitored; the effects of organic manure on the germination rate and growth of rapeseed seeds were measured;viable count,water content,and pH value of prepared fermentation starters were measured; main indicators( organic matter,nitrogen,phosphorus,and potassium) of organic fertilizer generated from fermentation were measured. From the indicators,the formula C3 and C4 were better,in the beginning of fermentation,the temperature rose rapidly,and it reached 40 ℃ in the second day; the water content dropped to below 35% in the 18 th day; the pH value underwent the process of declining-rising-stable,and the overall value showed slight rise,but the change was not great( 0-0. 5). C3 and C4 fermentation products had better effects on the germination and growth of rapeseeds. The germination rate of the rapeseed seeds was 100% and 97. 5% and the bud length was 15. 94 mm and 14. 57 mm,respectively,and the root length was45. 97 mm and 39. 44 mm,respectively. The content of organic matter in fermented organic manure was 86. 62% and 85. 17% respectively,and the total content of nitrogen,phosphorus and potassium was 8. 85% and 8. 22% respectively,and the pH was 7. 5 and 8. 0 respectively.All of these complied with the industry standard NY525-2012( organic matter ≥ 45%,and nitrogen,phosphorus,and potassium ≥ 5%,pH 5. 5-8. 5). The fermentation of fresh chicken manure was completed within 20 days,conforming to the requirements of large-scale organic fertilizer production factory for composting chicken manure into organic fertilizer.

Production of Phosphate-Rich Biofertiliser Using Vermicompost and Anaerobic Digestor Sludge—A Case Study

This paper presents the technology and cost effectiveness of production of phosphate rich biofertiliser (called PROM) by bioconversion of phosphate rock ore into soluble phosphates (that are directly assimilable by plants) in presence of an organic manure such as Vermicompost or anaerobic digestor sludge (discharged from biogas manufacturing units) and using a microbial culture of Bacillus megatherium var phosphaticum. PROM has been found to be an excellent, less expensive, substitute to synthetic phosphatic fertilisers such as SSP, MAP and DAP. This is based on real—life field trials. It is also possible to integrate the production of PROM, with biogas generation and the layout of such a more profitable, integrated scheme is also presented in this paper.

Effect of Chicken Manure, Compost and Cow Dung on the Growth and Yield of Sweet Potato [Ipomoea batatas (L.) Lam.] under Guinea Savannah Agroecological Zone of Ghana

Twelve percent (12%) of Ghanaians are food insecure, and climate-smart crops like sweet potatoes are required to help end poverty. Small-scale farmers in Ghana who produce low-technology, subsistence crops, such as sweet potatoes, are more food secure than those who do not. This study was initiated to investigate the effect of chicken manure, compost, and cow dung on the growth and yield of “apomuden”, “SARI-Nyoriberigu”, “SARI-Nan” and “kufour” sweet potato under the Guinea Savannah agroecological zone of Ghana. Organic fertilizer increased leaf chlorophyll content and leaf area index. The application of cow dung, chicken manure and compost in 2015 significantly increased total storage root yield by 38%, 55% and 98%, 62%, 45% and 37%, 52%, 61% and 44%, and 33%, 36% and 28% for SARI-Nyoriberigu, Kufour, SARI-Nan and Apomuden, respectively, when compared to the untreated check. In 2016, and in comparison with the untreated check, the application of cow dung, chicken manure and compost increased total storage root yield by 42%, 61% and 93%, 69%, 49% and 41%, 57%, 67% and 48%, and 36%, 39% and 30% for SARI-Nyoriberigu, Kufour, SARI-Nan and Apomuden, respectively. Hence, the application of organic fertilizers will increase sweet potato yield, give higher returns to resource-poor smallholder farmers and contribute to enhancing food and nutrition security.

Long-Term Manure Amendments Enhance Soil Aggregation and Carbon Saturation of Stable Pools in North China Plain

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.

Application of Highly Efficient Microbial Agent in Pig Manure Compost

[ 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.

Chitin, Biochar, and Animal Manures Impact on Eggplant and Green Pepper Yield and Quality

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-1) compared to fruits of plants grown in unamended control treatment (17.1 and 1.98 kg 5 Plants-1, 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.

Impact of Organic Soil Amendments on the Physical Characteristics and Yield Components of Potato （Solanum tuberosurn L.） in the Highlands of Cameroon

A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical characteristics, yield components and late blight disease severity of potato （Solanum tuberosum）. A two factorial treatment combination made up of fertilization schemes and sanitary measures were laid out in a randomized complete block design （RCBD） with four replicates and 10 treatments. Data collected were subjected to a multivariate ANOVA and means separated with the Dunnett t-test with Calliandra calothyrsus considered as the main treatment. Mineral fertilizers and Calliandra calothyrsus significantly augmented stem diameter, plant height and plant vigor, total and marketable yields, despite the fact that late blight severity was high in the two treatments. The correlation matrix showed that total yield had significant and positive correlation with stem diameter （r = 0.74）, plant height （r = 0.61）, plant vigor （r = 0.61） and marketable yield （r = 0.99） and negative correlation （r = -37） with late blight severity. The increase observed is attributed to the nutrient contents of the treatments applied. Leafy prunings of C. calothyrsus increase soil organic matter which probably improves moisture retention and biological activity. The highest late blight severity recorded between the 45 and 60 coincides with active development of plant canopy which influences disease severity and create a canopy microclimate conducive to disease development. This study suggests that Calliandra calothyrsus has the potential of improving potato production provided appropriate fungicide is used.

Change of Phosphate Fraction during Composting of Fresh Waste Leaves of Tobacco

Environmental issue has concerned the public with the build-up of soil phosphorus(P) following application of organic manure.This demands a fully understanding of the change of phosphorus during composting of fresh waste leaves of tobacco and finding out the status of P fertilizer in leaf-made manure.This study had shown that water-soluble and HCl-soluble phosphon were the dominant fractions of P in the compost of fresh waste leaves,in the ranges of 19%-41% and 17%-43%,respectively.However,the former declined progressively upon composting time,but the latter increased,indicating transformation of the more vulnerable water soluble P to the more recalcitrant HCl-extractable P.

Soil Amendments Enhanced Summer Squash Yield, Fruit Composition, Quality, and Soil Enzymes Activity

Summer squash, Cucurbita pepo was field grown under fourteen soil treatments: sewage sludge (SS);horse manure (HM);chicken manure (CM);vermicompost;inorganic fertilizer (Inorg);commercial organic fertilizer (Org);and no-mulch (NM) control treatment. Soil treatments were also mixed with biochar to make a total of 14 treatments to assess the impact on 1) squash fruit yield and quality, 2) fruit vitamin C, total phenols, and soluble sugars content, and 3) soil microbial activity expressed as urease and invertase secretions. Results revealed that SS treatments increased squash yield and fruit number by 114% and 116%, respectively compared to NM control treatment. Fruits of plants grown in Inorg mixed with biochar (InorgBio) increased fruits’ vitamin C, total phenols, and soluble sugars by 73%, 52%, and 7%, respectively compared to Inorg with no-biochar treatment. However, biochar was not consistent in increasing soil urease and invertase activities. The use of animal manure is an affordable way to reduce dependence on mineral fertilizers. Results revealed that the addition of biochar to Org fertilizer increased squash fruit weight and numbers of fruits compared to Org not treated with biochar. No single amendment increased all fruit composition and soil urease and invertase activities.

混合堆肥过程中自由空域(FAS)的层次效应及动态变化

城市污泥、猪粪混合堆肥试验表明 :升温期和高温期FAS分别为 4 2 3%、2 6 2 % ,在这 2个堆肥期内堆体上部的FAS明显高于下部 ,堆体内的空气能满足微生物的需求 ;降温期FAS为 5 2 4 % ,堆体上部的FAS高于中部 ,中部高于下部 ,FAS呈明显的层次效应 ;腐熟期FAS为 5 4 7% ,FAS的层次效应减弱 ,堆体上部和中部的通气性明显好于下部 .不同堆肥期剖面上下部FAS的差异由大到小分别为 :降温期 >高温期 >后熟期 >升温期 ;堆体内FAS由高到低为 :上部 >中部 >下部 .

添加PAAS对于污泥/猪粪混合堆肥的影响

以高吸水性树脂聚丙烯酸钠(PAAS)作为堆肥调理剂,利用自制的好氧堆肥反应器,研究PAAS对于污泥/猪粪混合堆肥的影响。实验结果表明:PAAS可以降低堆体的间隙水,提高堆体的空隙率及蓬松性,从而改善污泥/猪粪混合堆体的供氧条件,加快堆肥的进程;添加PAAS后,污泥/猪粪混合堆肥过程中的温度、含水率、pH、电导率、种子发芽指数、可挥发性固体含量等指标均发生较明显规律性变化,各指标的变化显示了PAAS对污泥/猪粪混合堆肥过程具有一定的促进作用。

Influence of bulking agents on CH_4,N_2O,and NH_3 emissions during rapid composting of pig manure from the Chinese Ganqinfen system

Mismanagement of the composting process can result in emissions of CH4,N2O,and NH3,which have caused severe environmental problems.This study was aimed at determining whether CH4,N2O,and NH3 emissions from composting are affected by bulking agents during rapid composting of pig manure from the Chinese Ganqinfen system.Three bulking agents,corn stalks,spent mushroom compost,and sawdust,were used in composting with pig manure in 60 L reactors with forced aeration for more than a month.Gas emissions were measured continuously,and detailed gas emission patterns were obtained.Concentrations of NH3 and N2O from the composting pig manure mixed with corn stalks or sawdust were higher than those from the spent mushroom compost treatment,especially the sawdust treatment,which had the highest total nitrogen loss among the three runs.Most of the nitrogen was lost in the form of NH3,which accounts for 11.16% to 35.69% of the initial nitrogen.One-way analysis of variance for NH3emission showed no significant differences between the corn stalk and sawdust treatments,but a significant difference was noted between the spent mushroom compost and sawdust treatments.The introduction of sawdust reduced CH4emission more than the corn stalks and spent mushroom compost.However,there were no significant differences among the three runs for total carbon loss.All treatments were matured after 30 d.

Investigation and analysis of the linkage mechanism and whole process cost of livestock manure organic fertilizer

In recent years,the utilization of manure resources for livestock and poultry farming has attracted a widespread attention,and manure resources utilization models suitable for different regional characteristics have formed gradually.Among them,the production of organic fertilizer from animal manure is a vital utilization method.However,there are still some problems such as high production costs,difficult sales,and the unwillingness of farmers to use organic fertilizers which have affected the breeding cycle and the sustainability of manure treatment in livestock and poultry breeding.This article selected 371 organic fertilizer plants,related farms and farmers in China,focusing on the main links of the entire process of livestock manure-organic fertilizer-farm application,and studied the mode of animal manure collection by organic fertilizer plants.The costs of organic fertilizer production and farmland application were discussed.Moreover,suggestions were made for the promotion and implementation of large-scale organic fertilizers to make good utilization of manure resources in livestock and poultry farming.

Environmental effects and risk control of antibiotic resistance genes in the organic solid waste aerobic composting system: A review

Antibiotic resistance genes(ARGs)have been diffusely detected in several kinds of organic solid waste,such as livestock manure,sludge,antibiotic fermentation residues,and food waste,thus attracting great attention.Aerobic composting,which is an effective,harmless treatment method for organic solid waste to promote recycling,has been identified to also aid in ARG reduction.However,the effect of composting in removing ARGs from organic solid waste has recently become controversial.Thus,this article summarizes and reviews the research on ARGs in relation to composting in the past 5 years.ARGs in organic solid waste could spread in different environmental media,including soil and the atmosphere,which could widen environmental risks.However,the conventional composting technology had limited effect on ARGs removal from organic solid waste.Improved composting processes,such as hyperthermophilic temperature composting,could effectively remove ARGs,and the HGT of ARGs and the microbial communities are identified as vital influencing factors.Currently,during the composting process,ARGs were mainly affected by three response pathways,(Ⅰ)“Microenvironment-ARGs”;(Ⅱ)“Microenvironment-microorganisms-ARGs”;(Ⅲ)“Microorganisms-horizontal gene transfer-ARGs”,respectively.Response pathway Ⅱ had been studied the most which was believed that microbial community was an important factor affecting ARGs.In response pathway Ⅲ,mainly believed that MGEs played an important role and paid less attention to eARGs.Further research on the role and impact of eARGs in ARGs may be considered in the future.It aims to provide support for further research on environmental risk control of ARGs in organic solid waste.

Influence of dissolved organic matter on methylmercury transformation during aerobic composting of municipal sewage sludge under different C/N ratios

Current knowledge about the transformation of total mercury and methylmercury(Me Hg) in aerobic composting process is limited. In this study, the composition and transformation of mercury and dissovled organic matter(DOM) in aerobic composting process of municipal sewage sludge were were comprehensively characterized, and the differences among the three C/N ratio(20, 26 and 30) were investigated. The main form of mercury in C/N 20 and 26 was organo-chelated Hg(F3, 46%-60%);while the main form of mercury in C/N 30 was mercuric sulfide(F5, 64%-70%). The main component of DOM in C/N 20 and 26 were tyrosine-like substance(C1, 53%-76%) while the main fractions in C/N 30 were tyrosine-like substance(C1, 28%-37%) and fulvic-like substance(C2, 17%-39%). The mercury and DOM varied significantly during the 9 days composting process. Compared to C/N 20 and 26, C/N 30 produced the less Me Hg after aerobic composting process, with values of 658%(C/N 20), 1400%(C/N 26) and 139%(C/N 30) of the initial, respectively. Meanwhile, C/N 30 produced the best compost showed greater degree of DOM molecular condensation and humification. Hg fraction had been altered by DOM, as indicated by a significant correlation between mercury species and DOM components. Notably, C/N 30 should be used as an appropriate C/N ratio to control the methylation processes of mercury and degration of DOM.

Phosphorus Recycling from Wastes

The plant phosphorus (P) uptake by Italian ryegrass using organic wastes such as sewage sludge, biochar, composted sewage sludge and spent wetland filters as fertilizer was investigated in pot experiments after manipulating the wastes pH by mixing with other wastes giving acidification by acetic acid and compost leachate, and liming by concrete waste and lime. Pots with no fertilizer and with mineral fertilizer served as control. Available P was measured both with passive diffuse gradient thin film (DGT) samplers and by P uptake in the grass. The pH in the treated waste was about 4 in the acid treatment, and more than 11 in the high pH treatment. The pH in the pot during the grass production was adjusted to normal levels. The P uptake increased up to 56% after pH treatment of the waste. The P uptake responded both to the high and low pH treatments, probably due to the prevalence of different P species. The more extreme pH treatments gave the highest uptake. The DGT uptake gave the same broad picture in the pots fertilized with biochar but not in pots with sludge, and, also, without the separation between high and low treatments. The passive samplers correlated relatively well with the measured grass uptake. A principal component (PCA) analysis showed that the P uptake as measured by the DGT correlated with P, potassium (K) and silicon (Si) concentrations, at to a lower degrade with iron (Fe) and lead (Pb), and was uncorrelated with nickel (Ni) and cupper (Cu). In summary we can say that the pH treatment of the different organic wastes increased the plant P availability. The smallest increase was in the wetland filter that also had the lowest P total uptake. Also the lupin treatment increased the plant P uptake.

规模化猪场粪污处理利用现状及案例分析

规模化猪场在养殖过程中会产生大量的粪污,如果不加以妥善处理与利用,将对环境和公共健康造成严重威胁。粪污处理与资源化利用成为实现养猪业可持续发展的关键环节。本文探讨了规模化猪场粪污的危害,介绍了规模化猪场粪污集中收集系统及目前规模化猪场在猪舍粪污处理中使用的尿泡粪和机械清粪2种清粪工艺,并详细讨论了生物发酵、厌氧消化、好氧处理等多种方法对固体粪污和液体污水的处理技术,以满足不同规模化养猪场的清粪需求。同时,探讨了规模化猪场种养结合生态循环利用和工业化深度处理2种主要的粪污处理利用模式。展望了未来科技创新对粪污处理与利用的推动作用,呼吁各方共同努力,以实现养猪企业的可持续发展、保障环境和人类健康的计划。本文为规模化养猪场选择粪污处理技术和利用模式提供了有益的参考,有助于环境保护和养猪业可持续发展。

畜禽粪便超高温堆肥技术研究进展

本研究旨在深入探究超高温堆肥技术在畜禽粪便处理领域的研究现状与应用潜力。通过分析超高温堆肥中试研究、超高温堆肥工程案例和超高温堆肥产物的质量及其应用效果,结果显示,外源供热和超嗜热菌剂添加是实现超高温堆肥的关键因素,其中超嗜热菌剂的添加尤为关键。研究表明,超高温堆肥适用于不同规模和不同种类的畜禽粪便处理,具有经济可行性。同时,超高温堆肥的产物符合中国有机肥料标准,并在种植中显示出良好的效果,具有广阔的推广应用前景。然而,超高温堆肥的微生物菌株资源挖掘利用和超高温堆肥产物的大田应用示范等工作仍有待开展。