Cattle Manure Treatment Research Articles

Vermifiltration as a green solution to promote digestate reuse in agriculture in small-scale farms

Digestates from low-tech digesters need to be post-treated to ensure their safe agricultural reuse. This study evaluated, for the first time, vermifiltration as a post-treatment for the digestate from a low-tech digester implemented in a small-scale farm, treating cattle manure and cheese whey under psychrophilic conditions. Vermifiltration performance was monitored in terms of solids, organic matter, nutrients, and pathogens removal efficiency. In addition, the growth of earthworms (Eisenia foetida) and their role in the process was evaluated. Finally, the vermicompost and the effluent of the vermifilter were characterized in order to assess their potential reuse in agriculture.Vermifilters showed high removal efficiency of chemical oxygen demand (55–90%), total solids (60–80%), ammonium nitrogen (83–97%), and phosphate-P (28–49%). Earthworms effectively grew and reproduced on digestate (i.e. earthworms number increased by 183%), enhancing the vermifiltration performance, while reducing clogging and odour-related issues. Both the vermicompost and effluent produced complied with legislation limits established for soil improvers and wastewater for fertigation, respectively. Indeed, there was an absence of pathogens and non-detectable heavy metals concentrations. Vermifiltration may be thus considered a suitable post-treatment option for the digestate from low-tech digesters, allowing for its safe agricultural reuse and boosting the circular bioeconomy in small-scale farms.

Effect of soil nutrient management on soil weed seed bank dynamics across a soil fertility gradient in smallholder farms, Eastern Zimbabwe

Weed seed banks are latent biotic stress contributors to low crop production among smallholder farms. The objective of this study was to investigate effect of repeated soil nutrient amendments on weed seed bank dynamics in eastern Zimbabwe. Soil samples were taken from three farms with low, medium and high soil organic carbon (SOC) along the catena. Sampled treatments included varying combinations of compound D (7%N, 14%P, 7% K) fertiliser, cattle manure and lime. Weeds that emerged per plot were counted by species and data was tested for normality before running a linear mixed-effects model and Restricted Maximum Likelihood. Principal Component Analysis (PCA) was performed to establish the relationship between seasons, SOC, soil nutrient amendment, and emerged weeds. Significant (p < .05) species richness (Margalef index), and Shannon Weiner index were recorded in the medium (6.4g kg-1soil), high (8 g kg-1 soil) and low (< 3.9 g kg-1soil) SOC. Weed species emergence was significantly (p < .05) influenced by the level of SOC along the catena positions, representing results from the source. Emergency and abundance of weeds such as Richardia scabra, was associated with low SOC acidic sandy soils from the upper catena. However, application of nutrients (NPK+lime treatment) reduced weed species counts from 1.96±0.12 to 1.4±0.12. Cattle manure and NPK+CM treatments recorded significantly higher weed emergence, and weed biomass; compared to the control. Clearly, cattle manure treatments significantly increase the soil weed seed bank; thus, weeding intensity is likely to increase in cattle manure treated fields.

Effect of composting and storage on the microbiome and resistome of cattle manure from a commercial dairy farm in Poland.

Manure from food-producing animals, rich in antibiotic-resistant bacteria and antibiotic resistance genes (ARGs), poses significant environmental and healthcare risks. Despite global efforts, most manure is not adequately processed before use on fields, escalating the spread of antimicrobial resistance. This study examined how different cattle manure treatments, including composting and storage, affect its microbiome and resistome. The changes occurring in the microbiome and resistome of the treated manure samples were compared with those of raw samples by high-throughput qPCR for ARGs tracking and sequencing of the V3-V4 variable region of the 16S rRNA gene to indicate bacterial community composition. We identified 203 ARGs and mobile genetic elements (MGEs) in raw manure. Post-treatment reduced these to 76 in composted and 51 in stored samples. Notably, beta-lactam, cross-resistance to macrolides, lincosamides and streptogramin B (MLSB), and vancomycin resistance genes decreased, while genes linked to MGEs, integrons, and sulfonamide resistance increased after composting. Overall, total resistance gene abundance significantly dropped with both treatments. During composting, the relative abundance of genes was lower midway than at the end. Moreover, higher biodiversity was observed in samples after composting than storage. Our current research shows that both composting and storage effectively reduce ARGs in cattle manure. However, it is challenging to determine which method is superior, as different groups of resistance genes react differently to each treatment, even though a notable overall reduction in ARGs is observed.

Soil chemical properties 12 years after termination of cattle manure and swine effluent applications

AbstractFor how long the nutrient supply from long‐term application of manure and swine effluent will last to sustain crop production after applications had ceased is a research gap. We quantified the change in soil chemical properties 12 years after cattle manure and swine effluent applications had ceased. Data were collected in 2008 (termination of applications) and 2020 on a long‐term animal waste study at the Kansas State University, Southwest Research‐Extension Center near Tribune, KS. Treatments were three levels of cattle manure and swine effluent (phosphorus, P; nitrogen, N; and 2N) and an untreated control. Soil profile NO3‐N declined 78%–95%, 70%–82%, and 58% from the initial amount in 2008 compared to the amount remaining in 2020 in the swine effluent, cattle manure, and an untreated check, respectively. Profile NO3‐N levels were greatly elevated by the P‐based swine effluent treatment and the 2N rate of both cattle manure and swine effluent and remained high (>250 kg ha−1) after 12 years. Total nitrogen in the surface soil decreased by 11%–27% for cattle manure treatments with little change in the swine effluent and check treatments. Total carbon concentration in the surface soil decreased from 22% to 31% for cattle manure treatments and from 7% to 14% for swine effluent and check treatments. Mehlich‐3 P decreased significantly for the cattle manure treatments (41%–53%) but still remained very high (>100 mg kg−1). Soil test P levels in the swine treatments were similar to the check treatment. Application of cattle manure and swine effluent has lasting effects on many soil chemical properties long after ceasing applications.

Partial wet oxidation of dairy manure as a pretreatment process to produce acetic acid 'a Source Growth of Methanogens'.

Wet oxidation can be an effective process for the pretreatment of complex biomass such as lignocellulose. However, studies on the use of wet oxidation for treating solid waste such as dairy manure are limited. The use of partial wet oxidation to convert dairy manure into low molecular weight carboxylic acids as final products were investigated. This work focuses on the performance of the sub-critical wet oxidation treatment of dairy cattle manure as a conversion/pretreatment process to release matter from the lignocellulosic fraction rather than a destructive process. The operating conditions were controlled at the short residence time and optimal temperature in the presence of oxygen under a pressure of 120 psi. The thermal hydrolysis under wet oxidation significantly affected conversion manure slurry into organic acids. The concentration of acetic acid reached 1778 mg L-1, achieved at 190°C (60 minutes reaction time) as the reaction temperature increased within the range of 150°C-200°C, total organic carbon was reduced and monomers in the process liquids decreased. On the other hand, soluble COD in process liquids increased with an increment in reaction temperature. The results provide insights into technical options to pretreat dairy manure to improve biochemical conversion yield.

Comparative study on aerobic compost performance, microbial communities and metabolic functions between human feces and cattle manure composting

Aerobic composting is an efficient method to treat animal manure, but comparative study in terms of composting between human feces with herbivore manure was very limited. The objective of this study was to explore the differences of composting performance, microbial communities as well as its metabolic functions between human feces (HF) and cattle manure (CM) composting using physicochemical analysis, 16S rRNA sequencing and PICRUSt function prediction. The results showed that HF treatment did not meet the compost maturity standard. Compared with CM treatment, the HF compost had the lower humus content and humic acid/fulvic acid ratio at the end of composting, indicating the lower humification degree under the same composting conditions. This was because the relative abundance of Actinobacteria and Proteobacteria treated with HF was lower than CM treatment during the composting process. In addition, PICRUSt analysis revealed that HF treatment was less abundant than CM treatment in genes related to metabolism, especially in Valine, leucine and isoleucine biosynthesis and C5-Branched dibasic acid metabolism, which were the dominant metabolic pathways belonging to amino acid and carbohydrate metabolism, respectively. Therefore, considering the excellent composting performance of cattle manure, it was recommended to add some cattle manure into raw materials during human manure composting. This study could provide valuable reference for the harmless treatment and resource utilization of human feces and cattle manure.

Long-term different fertilization regimes impact on the fate of root-derived C and microbial community structure in paddy soil

It is known that fertilization pattern could alter soil nutrient and organic matter status. However, it is still unclear how photosynthesized C is distributed in rice–rhizosphere soil-microbial system and its influencing factors due to fertilization pattern and subsequent changes in soil fertility. This study examined the allocation of rice photosynthetic C in rice–rhizosphere soil–microbial systems and the changes in microbial community under three long-term fertilizer regimes. Rice was grown in soils with 8-year history of no fertilizer, inorganic fertilizer (NPK) or NPK fertilizer plus cattle manure (NPK + CM), and was pulse–labelled with 13CO2 at rice tillering stage. The results showed that 13C incorporation in rice-rhizosphere soil system was the highest in the NPK + CM treatment, increased by 489% and 28.9% compared to unfertilized control and the NPK alone. In the >2 mm aggregate fraction, the 13C enrichment was higher in NPK + CM compared to no-fertilized control and NPK treatments. Total PLFA and PLFA groups contents in all aggregate size fractions were the greatest in the NPK + CM treatment. Partial least squares path modelling analysis revealed that microbial community in large macroaggregate (>2 mm) was significantly (P < 0.05) affected by root properties, while soil fertility had a significant (P < 0.01) impact on microbial community in microaggregate (<0.25 mm). The redundancy analysis showed that soil parameters except soil alkali-hydro nitrogen (AN) significantly impacted the soil microbial communities. Through canonical variation partitioning analysis, soil available K was the most important factor leading to variance (11.4%) in microbial community composition. On the other hand, soil pH significantly (P < 0.05) affected the distribution of 13C in microbe community. More than 20% of 13C was incorporated into G– and G+ bacteria across all treatments. Overall, it was observed the NPK fertilizer plus cattle manure treatment was most conducive to retain C from root exudates in the rice-rhizosphere soil-microbial system.

Insight into humification of mushroom residues under addition of Rich-N sources: Comparing key molecular evolution processes using EEM-PARAFAC and 2D-FTIR-COS analysis

Accelerating the humification of organic solid waste is one of the most important issues in composting. This present study aims to study and compare the humification process of different rich-N sources (chicken manure, cattle manure, and urea) addition during the composting of mushroom residues, from macro physicochemical properties to micro humic molecular structure evolution process. The physicochemical elements and humic components were determined for evaluating the compost quality and humification degree as composting proceed. The coupled analysis of excitation-emission matrix with parallel factor analysis (EEM-PARAFAC) and two-dimensional correlation with Fourier transform infrared spectrum (2D-FTIR-COS) were used to characterize the functional molecular structure evolution of dissolved organic matter during humification process. The results indicated that the rank order for humification level were the treatments of chicken manure (HM), urea (UM), cattle manure (CM), and single mushroom residue treatment (CK), with their humification index of 22.18%, 22.05%, 18.47%, and 16.52%, respectively. Humic substance, humic acid, and fulvic acid were obtained the highest in HM treatment with contents of 35.41 ± 0.86%, 23.32 ± 1.57%, and 10.97 ± 0.52%, respectively. The rich-N source addition enhanced the degradation of protein-like and polysaccharides-like substances in dissolved organic matter, thus accelerating the humification process of mushroom residues. The key structure evolution of dissolved organic matter in the HM treatment, in which the CO and CC stretching of quinone, amide, or ketone, and the C–O stretching of polysaccharides may be responsible for the faster formation of humus compared to the other nitrogen treatments. In this study, redundancy analysis indicated that the total nitrogen (TN) and nitrate nitrogen (NO3−-N) may be the potential indicators for determining the humification level as composting proceed. The result provides significant insight into the humification mechanism of mushroom residue under different types of nitrogen sources at the molecular level, and will be reference for improving the composting technique in practical field.

Impact of Swine and Cattle Manure Treatment on the Microbial Composition and Resistome of Soil and Drainage Water.

Evaluating potential environmental and clinical impacts of industrial antibiotic use is critical in mitigating the spread of antimicrobial resistance. Using soil columns to simulate field application of swine or cattle manure and subsequent rain events, and a targeted qPCR-based approach, we tracked resistance genes from source manures and identified important differences in antimicrobial resistance gene transport and enrichment over time in the soil and water of artificially drained cropland. The source manures had distinct microbial community and resistance gene profiles, and these differences were also reflected in the soil columns after manure application. Antibiotic resistance genes (ARGs) were only significantly enriched in effluent samples following the first rain event (day 11) for both soil types compared to the control columns, illustrating the high background level of resistance present in the control soils chosen. For swine, the genes tetQ, tet(36), tet44, tetM, sul2 and ant(6)-ib persisted in the soil columns, whereas tetO, strB and sul1 persisted in effluent samples. Conversely, for cattle manure sul2 and strB persisted in both soil and effluent. The distinct temporal dynamics of ARG distribution between soil and effluent water for each manure type can be used to inform potential mitigation strategies in the future.

Effects of long-term fertilization with contemporary Danish human urine, composted household waste and sewage sludge on soil nematode abundance and community structure

It is desirable to recycle the urban waste products human urine, composted household waste and sewage sludge as fertilizers to agricultural fields. This could minimize the use of NPK fertilizer, improve soil structure and store carbon. However, waste products may contain heavy metals, persistent organic pollutants (POP) and plastics, and there are concerns that long-term build-up of these substances will cause unwanted effects on soil health.Nematodes are ubiquitous and numerous in soil ecosystems. Abundance and community structure of soil nematodes can be used as indicators of soil health, as some species are vulnerable to pollution. There are well-developed methods for detecting environmental changes based on nematode community structure.At the long-term CRUCIAL field experiment, where alternative fertilizer products have been applied since 2003, we measured effects of long-term fertilization with human urine, composted household waste and sewage sludge on soil properties (pH, soil organic matter and nitrogen availability), abundance of soil microorganisms (bacteria, fungi, small protozoa and ciliates) and nematode trophic groups compared to plots with unfertilized, NPK and cattle manure treatment. Sampling and assessments were done three times during a growth season. Further, we assessed the composition of nematode communities using metabarcoding.Treatments with a high input of organic matter (cattle manure, composted household waste and sewage sludge) had high abundances of bacteria and thus bacterial grazers (small protozoa, ciliates, and bacterial feeding nematodes). We found a significant correlation between nematode community structure and pH and organic matter. We calculated the nematode Maturity Index 2–5 (pollution indicator) based on metabarcoding data, which did not differ significantly between the treatments.We conclude that long-term fertilization with different types of contemporary Danish urban waste products affects both soil properties and abundance of soil organisms, the latter largely reflecting the organic matter input of the fertilizer treatments. We found no adverse effect on nematode communities that could indicate pollution-induced stress on nematofauna or decreased soil fertility.

Nitrogen and Phosphorus Replacement Value of Three Representative Livestock Manures Applied to Summer Maize in the North China Plain

Land application of livestock manure may reduce the use of mineral fertilizers and alleviate the environmental degradation associated with mineral fertilizers application. However, how to optimize utilization of livestock manure value is not well understood and documentation regarding the nitrogen (N) and phosphorus (P) fertilizer replacement values (NFRV and PFRV, respectively) needs further scrutiny. Therefore, three representative livestock manures, i.e., pig, chicken, and cattle manure, were applied at different usages to assess their N and P availability in comparison to reference mineral fertilizers over summer maize growing seasons. The results show that the average NFRVs of pig, chicken, and cattle manures were 41.7–58.4%, 27.5–44.4%, and −3.6–36.1%, respectively, when based on different references (grain yield, total dry matter yield, grain N uptake, total N uptake), at different N application levels. The NFRV increased with the elevated N application rate for cattle manure treatment. In the P trials, livestock manure had a higher PFRV at a low P application level, and the average PFRVs of pig, chicken, and cattle manures were 80.3–164.8%, 77.9–143.7%, and 94.1–168.0%, respectively, at different P application levels. We conclude that livestock manure produced the lowest NFRV and highest PFRV at a low fertilizer application rate; pig manure had the highest N availability; and cattle manure had the highest P availability.

Carbon footprint assessment of a whole dairy farming system with a biogas plant and the use of solid fraction of digestate as a recycled bedding material

Biogas generated from livestock manure is a renewable energy source and the digestate is used as a fertilizer. Moreover, dewatered biogas digestate can be used as a bedding material (recycled bedding material). The aims of the present study were to model a whole dairy system with a biogas plant using recycled bedding material and to assess the life cycle greenhouse gas (GHG) emissions. Emissions from the material flow of dairy cattle production, manure treatment and organic fertilizer application to on-farm crops were evaluated. In the emissions from organic fertilizer storage and recycled bedding material production, CH4 emission was decreased by 43.0%, and consequently the system with a biogas plant reduced total GHG emissions by 6.8% compared with conventional slurry storage and straw bedding. The use of recycled bedding material from a biogas plant has the potential to create a resource cycle and to be beneficial as a GHG mitigation strategy.

Cattle Manure Alters the Soil Nutritional Status and Soybean Yield (Glycine max L. Merr.)

Soybean is one of the most important crops globally, despite significant numbers the crop in the Cerrado biome presents low natural fertility with a higher demand for fertilization. Seeking to improve the production of culture by reducing costs there is the possibility of using organic waste, which can be a very advantageous and interesting option when well used. The objective of this work was to evaluate the physiological, nutritional, and productive aspects of soybean crops grown with cattle manure associated with chemical fertilizers. The experimental design was in randomized blocks with eight replications (4 for destructive analyses and 4 for grain harvesting). The treatments were composed of 5 doses of cattle manure (0.0, 2.5, 5.0, 10.0, and 20.0 t ha-1) and control treatment (Control) without fertilization, without the use of manure and mineral fertilizer. The cattle manure provided a positive increase in the increase of levels of Ca, Mg, M.O, P, K, Fe, Zn and in the characteristics of plant height, stem diameter, soybean node number, dry weight of shoot, Falker chlorophyll index, root length and dry weight of root. The dose of 20.0 t ha-1 was the best response dose for soil nutritional conditioning for both physical and chemical characteristics, with an average increase of 68.26% in a comparison with only the use of conventional mineral fertilization.

Nitrapyrin Addition Mitigated CO2 Emission from a Calcareous Soil Was Closely Associated with Its Effect on Decreasing Cellulolytic Fungal Community Diversity.

Application of nitrification inhibitors (NIs) has been widely used to inhibit nitrification and reduce N2O emissions. However, the impacts of NI addition on soil carbon transformation and carbon-degrading microbial communities have not been well explored. Here, a microcosm experiment was carried out, and four treatments were designed: (i) unfertilized control, (ii) urea alone, (iii) urea plus cattle manure, and (iv) urea plus cattle manure with nitrapyrin. The influence of nitrapyrin on soil CO2 emissions, carbon-degrading extracellular enzyme activities, and the abundance and diversity of the cbhI community was investigated. Compared to the treatment of urea plus cattle manure, nitrapyrin significantly decreased cumulative CO2 emissions by 51.8%. Moreover, cbhI community gene copies and their α-diversities (P < 0.05) were also significantly reduced by nitrapyrin application. A partial least squares path model showed that CO2 emission was positively associated with cbhI community α-diversity but negatively associated with nitrapyrin addition. We conclude that the mitigation of soil CO2 emissions by nitrapyrin can be ascribed to its effects on decreasing of cellulose-degrading gene community diversity. Our findings provide new insights into the side-effects of nitrapyrin on abating CO2 emission.

Vermicomposting of cow manure: Effect of time on earthworm biomass and chemical, physical, and biological properties of vermicompost

Vermicomposting is a biological process for efficient cattle manure treatment, but the vermicomposting time determines the quality of the vermicompost. The objective of this study was to evaluate the effect of cattle manure vermicomposting time on earthworm biomass and the changes in physical, chemical, and biological in properties of the vermicompost. The cattle manure was inoculated with Eisenia andrei earthworms and conducted vermicomposting for 0, 15, 30, 45, 60, and 120 days. The analysis of 44 chemical, physical, and biological properties allowed the vermicomposting process to be divided into initial (<45 days) and final (45–120 days) phases. The initial phase was characterized by high microbial activity and the final by high physical–chemical transformation of the vermicompost and an increase in earthworm density. The organic matter aromaticity increased until the 45th day, subsequently decreasing. Although 30 d of vermicompost are sufficient to obtain a high-quality organic fertilizer, 120 d are necessary for producing matrices.

Feasibility of Coupling Anaerobic Digestion and Hydrothermal Carbonization: Analyzing Thermal Demand

Anaerobic digestion is a biological process with wide application for the treatment of high organic-containing streams. The production of biogas and the lack of oxygen requirements are the main energetic advantages of this process. However, the digested stream may not readily find a final disposal outlet under certain circumstances. The present manuscript analyzed the feasibility of valorizing digestate by the hydrothermal carbonization (HTC) process. A hypothetical plant treating cattle manure and cheese whey as co-substrate (25% v/w, wet weight) was studied. The global performance was evaluated using available data reported in the literature. The best configuration was digestion as a first stage with the subsequent treatment of digestate in an HTC unit. The treatment of manure as sole substrate reported a value of 752 m3/d of biogas which could be increased to 1076 m3/d (43% increase) when coupling an HTC unit for digestate post-treatment and the introduction of the co-substrate. However, the high energy demand of the combined configurations indicated, as the best alternative, the valorization of just a fraction (15%) of digestate to provide the benefits of enhancing biogas production. This configuration presented a much better energy performance than the thermal hydrolysis pre-treatment of manure. The increase in biogas production does not compensate for the high energy demand of the pre-treatment unit. However, several technical factors still need further research to make this alternative a reality, as it is the handling and pumping of high solid slurries that significantly affects the energy demand of the thermal treatment units and the possible toxicity of hydrochar when used in a biological process.

Результаты исследований процесса обработки навоза крупного рогатого скота в аппаратах вихревого слоя

The results of studies of the of cattle manure treatment in the vortex layer apparatus are presented. It has been found that these devices can treat manure having a moisture content of more than 93% and a particle content of maximum 7 mm in size. With an increase in the moisture content of manure from 93% to 96%, the energy intensity of the dispersion process decreases from 0.7 kWh / t to 0.53 kWh / t, the productivity increases to 22 t / h, and the weight of ferromagnetic elements loaded into the apparatus should be in the range of 285 g to 400 g.

CERES‐Maize model performance under mineral and organic fertilization in nemoral climate conditions

AbstractLittle information is available regarding the performance of the CERES‐Maize model under nemoral climate conditions. Therefore, this study aims to estimate and compare major soil‐plant N cycle parameters in grain maize (Zea mays L.) crop after application of synthetic and different organic fertilizers solely or in combination in nemoral zone maize production, using the Decision Support System for Agrotechnology Transfer (DSSAT) model. Field experiments carried out during 2015, 2016, and 2017 in Akademija (Lithuania) were considered for model calibration and validation. The model was successfully validated for total aboveground biomass (TAB, R2 = .89), grain yield (GY, R2 = .85), and acceptably for leaf area index (LAI, R2 = .57), total plant N uptake (R2 = .61), and residual soil mineral N (R2 = .64). The lower plant N uptake and soil mineral nitrogen (SMN) observed for the pelletized cattle manure (PCM) and green waste compost (GWC) treatments compared to the fertilization with synthetic ammonium nitrate (AN) were successfully captured by the model. Finally, the model provided reasonable predictions of the temporal dynamics of measured soil water content (SWC) and soil temperature. The validated model was further used to provide N loss estimations during the maize growing seasons via leaching and gaseous emissions. The results showed that the CERES‐Maize model can successfully be used to simulate maize growth under the extreme climatic conditions of the nemoral zone in combination with different N managements. Nevertheless, additional efforts are needed to verify and fine‐tune the model to comprehensively simulate the N cycle, especially losses by drainage water and gaseous emissions.

An Environmental Assessment of Cattle Manure and Urea Fertilizer Treatments for Corn Production in the Northern Great Plains

HighlightsThe Integrated Farm System Model appropriately represented average emission rates measured in corn production.Compared to the use of feedlot manure, application of bedded pack manure generally increased N and P losses.Compared to inorganic fertilizer use, cattle manure increased soluble P loss while reducing GHG emission.Production and environmental differences among production systems were similar under recent and future climates.Abstract. Nitrogen (N), phosphorus (P), and carbon (C) emissions from livestock systems have become important regional, national, and international concerns. Our objective was to use process-level simulation to explore differences among manure and inorganic fertilizer treatments in a corn production system used to feed finishing cattle in the Northern Great Plains region of the U.S. Our analysis included model assessment, simulation to compare treatments under recent climate, and comparisons using projected midcentury climate. The Integrated Farm System Model was evaluated in representing the performance and nutrient losses of corn production using cattle manure without bedding, manure with bedding, urea, and no fertilization treatments. Two-year field experiments conducted near Clay Center, Nebraska; Brookings, South Dakota; and Fargo, North Dakota provided observed emission data following these treatments. Means of simulated emission rates of methane, ammonia, and nitrous oxide were generally similar to those observed from field-applied manure or urea fertilizer. Simulation of corn production systems over 25 years of recent climate showed greater soluble P runoff with use of feedlot and bedded manure compared to use of inorganic fertilizers, but life-cycle fossil energy use and greenhouse gas emission were decreased. Compared to feedlot manure, application of bedded pack manure generally increased N and P losses in corn production by retaining more N in manure removed from a bedded housing facility and through increased runoff because a large portion of the stover was removed from the cornfield for use as bedding material. Simulation of these treatments using projected midcentury climate indicated a trend toward a small increase in simulated grain production in the Dakotas and a small decrease for irrigated corn in Nebraska. Climate differences affected the three production systems similarly, so production and environmental impact differences among the fertilization systems under future climate were similar to those obtained under recent climate. Keywords: Climate change, Greenhouse gas, Integrated Farm System Model, Nutrient losses.

The aftereffect of winter wheat on pea yield, nitrogen surplus and nitrogen use efficiency in different cropping systems

The present study is part of a framework for researching the use of the field pea in cropping systems in order to improve its economic and environmental output. The specific aim was to investigate the effect of differently fertilised preceding winter wheat on subsequent field pea output in the same crop rotation. The field experiment was conducted in Tartu county, Estonia, in 2012–2017. Seven different cropping systems were investigated: four conventional with different treatments of mineral nitrogen fertilisers and three organic including catch crops and cattle manure treatment. The DM yield of field pea in winter wheat mineral N treatments 50–150 kg N ha-1 was 2699–2852 kg ha-1, which was 33% higher than in the organic systems. There were no significant differences (p &lt; 0.05) in nitrogen use efficiency (NUE) and N surplus between 50–150 kg N ha-1. The first 20 kg ha-1 mineral N with P25 and K95 gave a significantly higher pea yield compared to the treatment without mineral N. The catch crops reduced agronomic NUE and increased N surplus in the organic cropping systems.&#x0D;