Manure Systems Research Articles

Determinants of the Extent of Use of Climate-Smart Agricultural Practices by Farm Households in Southeast Nigeria

Climate change remains a threat to the ability of Nigeria to ensure food security, eradicate poverty and achieve sustainable development. Despite the unimaginable negative impacts, there is a dearth of empirical evidence on the drivers of the extent of use of Climate-Smart Agricultural (CSA) practices in Southeast Nigeria. A multistage random sampling technique was used to select 366 farming households. The primary data collected were analysed using descriptive statistics, adaptive strategy use index and ordered probit regression. The result showed that the majority (55.1%) of the respondents were males, married (81.3%) with a mean age of 48 years and on average, spent 11 years in education. The result of the extent of use of CSA practices revealed that the CSA practices frequently used were organic manure (0.9127), crop diversification (0.9117), crop rotation (0.9067) and mixed farming system (0.7411). The result of ordered probit showed that age (0.017), education (0.030), farming experience (0.082), farm size (0.239), extension access (0.543) and livestock ownership (0.429) influenced the extent of CSA practices. The study recommends a more robust extension outreach to rural farmers to enhance farmers' adoption and use of CSA practices to mitigate climate change and improve farm income.

Using kin discrimination to construct synthetic microbial communities of Bacillus subtilis strains impacts the growth of black soldier fly larvae.

Using synthetic microbial communities to promote host growth is an effective approach. However, the construction of such communities lacks theoretical guidance. Kin discrimination is an effective means by which strains can recognize themselves from non-self, and construct competitive microbial communities to produce more secondary metabolites. However, the construction of cooperative communities benefits from the widespread use of beneficial microorganisms. We used kin discrimination to construct synthetic communities (SCs) comprising 13 Bacillus subtilis strains from the surface and gut of black soldier fly (BSF) larvae. We assessed larval growth promotion in a pigeon manure system and found that the synthetic community comprising 4 strains (SC 4) had the most profound effect. Genomic analyses of these 4 strains revealed that their complementary functional genes underpinned the robust functionality of the cooperative synthetic community, highlighting the importance of strain diversity. After analyzing the bacterial composition of BSF larvae and the pigeon manure substrate, we observed that SC 4 altered the bacterial abundance in both the larval gut and pigeon manure. This also influenced microbial metabolic functions and co-occurrence network complexity. Kin discrimination facilitates the rapid construction of synthetic communities. The positive effects of SC 4 on larval weight gain resulted from the functional redundancy and complementarity among the strains. Furthermore, SC 4 may enhance larval growth by inducing shifts in the bacterial composition of the larval gut and pigeon manure. This elucidated how the SC promoted larval growth by regulating bacterial composition and provided theoretical guidance for the construction of SCs.

АНАЛИЗ СУЩЕСТВУЮЩИХ МЕТОДИК ОПРЕДЕЛЕНИЯ КАЧЕСТВЕННЫХ И КОЛИЧЕСТВЕННЫХ ХАРАКТЕРИСТИК НАВОЗА, ПОМЕТА ДЛЯ ОЦЕНКИ ЭМИССИИ ПАРНИКОВЫХ ГАЗОВ

Various methods of excrement, manure, dung and organic fertilizer characteristics determining in depending on the animals’ types (cattle, pigs, poultry), manure and dung processing’s technologies for climatically active substances (methane and nitrous oxide) emission calculating at various levels have been studied. The conducted studies have shown that to calculate greenhouse gas emissions - methane (CH4) and nitrous oxide (N2O) - from manure and dung processing by level 1systems’ method (a simplified method in which only data on livestock/poultry are required to estimate emissions, broken down by animals species/categories/subcategories, climatic regions or temperature conditions in combination with default emission factors) using it is more rational a calculation method based on the guidance documents’ values using. The values from the guidance documents are aggregated and do not fully reflect specific livestock/poultry complex situation, however these data are sufficient for this method’s level 1 calculating. For manure and dung greenhouse gas emissions systems processing more accurate calculations, the level 2 method is used (but more detailed information on manure and dung processing technologies is needed). It requires animals/poultry production data, used feed rations and weight gain during each reproduction cycle. The method of quantitative and qualitative excrement’s characteristics calculating based on the mass balance meeting these requirements. Analytical methods for the excrement, manure, dung and ready made organic fertilizers characteristics determining for each batch of fertilizer applied to agricultural land must be applied. The protocols’ values obtaining from laboratory analysis can also be used to greenhouse gas emissions from manure and dung processing systems calculating by the level 2 method using.

111 A Suspended Molasses Block Improves Post-Mixing Welfare of Gestating Sows

Abstract Most swine production systems in the US do not include access to environmental enrichment: an improvement in the biological functioning of captive animals resulting from modifications to their environment. Optimal enrichments such as straw, hay and silage are not acceptable due to manure system and biosecurity concerns. There remains a need to develop enrichment for pigs that is biologically relevant, safe for existing systems, biosecure, sustainable and cost effective. The aim of this study was to compare the behavior and welfare of sows over 2 weeks post-mixing when given access to a suspended molasses block (B - Barastoc Swine Block) or a metal chain (C). Three replicates of 36 LW × Yorkshire sows, balanced by parity, were mixed at d 42 post service in groups of 4, 6 or 8, with one of each group size per treatment. Groups were formed with equal numbers of sows from 2 large group pens, i.e., a group of 4 was formed using 2 sows from one pen, mixed with 2 sows from a second pen, and so on. Sow behavior and animal-based welfare measures were recorded 3 days before mixing, and d 1, 6 and 13 post-mixing. Welfare measures included tear stains, lesion scores, bursitis, shoulder sores, respiratory and cleanliness scores. Behavior included passive and active human-approach tests, where the human stood for 3 min against one wall of the pen to allow sows to approach, noting number to approach and touch the human and the latency to touch. Then at the end of the test, the human actively approached each sow in turn and touched the head of the sow, noting the response of the sow on a numerical scale. Data were analyzed using 2-way ANOVA with treatment and group size as factors. There were no treatment differences in bursitis, shoulder sores and respiratory scores, and no differences in time to approach and touch the human. However, B sows had smaller tear stains (d 6 and d 13, P < 0.001), decreased body lesion scores (d 1 and d 6, P < 0.05), and better body cleanliness scores (d 1, P < 0.05). Human approach test measures showed habituation over time, but B sows responded less to a human approaching and touching their head than C sows (d 6, P < 0.05). Groups of 6 had lowest tear stain scores (d 1, d 6 and d 13, P < 0.05) and were cleanest (d 13, P < 0.05). There was also a Group size*treatment interaction with groups of 6 having the lowest lesion scores in the C treatment, but the highest in the B treatment (d 1, d 6, and d 13, P < 0.05). The skin lesions scores indicate that aggression was lower in the pens with the blocks. Overall, the blocks improved sow welfare over the immediate 2-week post-mixing period, though group size may impact this.

Environmental impact and optimization suggestions of pig manure and wastewater treatment systems from a life cycle perspective

With the rapid development of the pig farming industry in China, a large amount of pig manure is inevitably generated. The management and utilization of pig manure in a sustainable approach require a systematic analysis of the environmental impacts generated from the existing pig manure treatment and disposal routes. In this study, three typical pig manure treatment and disposal routes: pig manure solid-liquid separation, i) wastewater biological treatment, direct land application of manure/sludge; ii) black-film anaerobic digestion of wastewater, mono-composting of manure/sludge and land use; iii) wastewater biological treatment, co-composting of manure/sludge and land use, were comparatively assessed in terms of their environmental impacts using the life cycle assessment. The results show that the added chemicals in wastewater treatment and the consumed electricity in composting the manure/sludge are the two main contributors to all environmental impacts. Thus, using green chemicals, controlling the dosage of added chemicals accurately, and selecting composting types with low energy consumption will significantly reduce the environmental burden of pig manure treatment and disposal routes. For the global warming potential of the evaluated three pig manure treatment and disposal routes, direct emissions of greenhouse gases during the composting process contribute the most, accounting for 77 %, 95 %, and 79 %, respectively. Furthermore, the struvite recovery with anaerobic digestion from pig manure will bring excellent environmental benefits, which will markedly offset the toxicity impacts and carbon emissions derived from pig manure treatment and disposal process. Overall, this work quantitatively evaluates the potential environmental impacts of the existing pig manure treatment and disposal routes, providing insights on optimization for future technical improvement and development.

Modeling ammonia emissions from manure in conventional, organic, and grazing dairy systems and practices to mitigate emissions

Almost 60% of all ammonia (NH3) emissions are from livestock manure. Understanding the sources and magnitude of NH3 emissions from manure systems is critical to implement mitigation strategies. This study models 13 archetypical conventional (5 farms), organic (5 farms), and grazing (3 farms) dairy farms to estimate NH3 emissions from manure at the barn, storage, and after land application. Mitigation practices related to management of the herd, crop production, and manure are subsequently modeled to quantify the change in NH3 emissions from manure by comparing archetypical practices with these alternative practices. A mass balance of nutrients is also conducted. Emissions per tonne of excreted manure for the manure system (barn, storage, and land application) range from 3.0 to 4.4 g of NH3 for conventional farms, 3.5 to 4.4 g of NH3 for organic farms, and 3.4 to 3.9 g of NH3 for grazing farms. For all farm types, storage and land application are the main sources of NH3 emissions from manure. In general, solid manures have higher emission intensities due to higher pH during storage (pH = 7.4 for liquid, 7.8 for slurry, and 8.5 for solid manure) and lower infiltration rates after land application when compared with slurry and liquid manures. The most effective management practices to reduce NH3 emissions from manure systems are combining solid-liquid separation with manure injection (up to 49% reduction in NH3 emissions), followed by injection alone, and reducing crude protein in the dairy ration, especially in organic and grazing farms that have grazing and forages as the main component of the dairy ration. This study also shows that the intensity of NH3 emissions from manure depends significantly on the functional unit and presents results per manure excreted, total solids in excreted manure, animal units, and fat- and protein-corrected milk.

Ammonia mitigation measures reduce greenhouse gas emissions from an integrated manure-cropland system

Increasing use of manure nutrients in crop production and decreasing the input of chemical fertilizers, is a promising way to achieve a more circular economy and more sustainable food systems. The integrated effects of amended composting manure with additives and a 50% substitution of chemical fertilizer nitrogen (N) input by amended manure N input to cropland were proved to halve ammonia (NH3) emissions from an integrate manure-cropland system. However, the accompanied impacts of these measures on greenhouse gas (GHG) emissions from the integrate manure-cropland system have not been well quantified. Here, we examined the effects of improved manure storage and treatment and its usage at field on GHG emissions from a system perspective, based on a two-year experiment in the North China Plain (NCP). Manure storage and treatment included natural storage (NS) and composting with straw, with or without amendment by zeolite (Z) and superphosphate (SP). Manure products were applied as basal fertilizer for both crops. Results showed that CH4 was the dominant GHG source in the natural storage treatment, whereas N2O dominated in the manure composting treatments. Amending manure with straw, Z and SP stimulated 15–48 times N2O emission and decreased CH4 emissions by 82%–91% during storage and treatment. Replacement of 50% synthetic fertilizer N by manure N decreased total system GHG emissions by 25%–34%. Differences between composted manure treatments in total system GHG emissions were relatively small, although comparatively higher in amended manure treatments; however, they promoted greater soil organic carbon sink activity, resulting in no significant difference in net global warming potential (GWP) and greenhouse gas emission intensity (GHGI). Application of amended manure produced high nitrogen use efficiency (NUE) in the integrated crop–manure system. The NH3 mitigation approach of replacing 50% of synthetic fertilizer N by amended manure N synergistically decreased total GHG emissions, increased system NUE and also increased the net economic benefit by 5%–11% over the 2 years of the experiment.

Farming system impacts the bioactive compounds, microbial diversity, aroma and color in edible red mini-roses (Rosa chinensis Jacq.)

Mini-roses (Rosa chinensis Jacq.) is largely used in salty dishes and desserts. This study evaluated instrumental color, sugars, organic acids, phenolics, volatiles, and the indigenous microbiota (fungi and bacteria) in edible mini-roses farmed in discarded fruits biocompost and animal manure systems. A descriptive sensory analysis of flowers was also performed. Mini-roses farmed in biocompost had higher luminosity and intensity of instrumental red color, a higher concentration of phenolic compounds, including anthocyanins related to red color, and fructose than mini-roses farmed in animal manure (p < 0.05). Furthermore, mini-roses farmed in biocompost had higher concentrations of various volatiles (p < 0.05), including hexyl acetate and cis-3 -hexenyl butyrate related to the fruity aroma. Bacterial groups related to plant growth-promoting such as Stenotrophomonas and endophilic fungal groups such as Eurotiales sp, Pleosporales sp were found in higher abundance (p < 0.05) in mini-roses farmed in biocompost. Mini-rose farmed in biocompost also received higher score (p < 0.05) for fruity aroma and red color than mini-rose mini-roses farmed in animal manure. Results indicate that farming mini-roses using biocompost from discarded fruits impacts the synthesis of phenolics and volatiles, resulting in a more intense fruity aroma and red color. Findings also suggest that the microbiota of mini-roses farmed in biocompost or animal manure do not represent a major risk for the safety of these products.

Surface electron-polarized biochar-enhanced anaerobic digestion mechanism revealed by metagenomic binning strategy

Inefficient electron transfer is a key bottleneck for anaerobic digestion (AD), which often leads to system instability. Here, we propose for the first time a new strategy to solve the problem by adding surface electron-polarized biochar to enhance methanogenesis by providing electrons to methanogens through surface electron-poor/rich regions. Pyrolysis conversion of pigeon manure to conductive materials (CM) containing electron-poor/rich regions is realized. Different levels of CM (2.5, 5 and 7.5 g/L) are used to enhance methane production from pig manure and rice straw co-digestion systems. It is found that the addition of 5 g/L CM results in the highest cumulative CH4 production (187.4 ± 8.0 mL/g VS substrate), 35.4% higher (P < 0.05) than the control (0 g/L). Methanogenic archaea are enriched. Synergistic metabolic mechanisms between the functional microorganism bin.CM52.160 (cellulose degradation) and bin.CM03.101 (methane production) are revealed by the metagenomic binning strategy. A large number of potentially unculturable electroactive microorganisms have been identified. This work provides important insights into the construction of micro-electric fields on material surfaces and offers a practical approach to improving AD performance.

Dual-Purpose Rye, Wheat, and Triticale Cover Crops Offer Increased Forage Production and Nutrient Management but Demonstrate Nitrogen Immobilization Dynamics

Dual-purpose cover crops (DPCCs) are gaining popularity for their potential to provide additional forage, while also providing significant ecosystem services. In the Northeastern United States, DPCCs can be incorporated into corn silage (Zea mays L.) production, increasing the environmental sustainability and economic resiliency of dairy systems. In a three-year field study, rye (Secale cereale L.), wheat (Triticum aestivum), and triticale (xTriticosecale) DPCCs provided an average of 4.1 Mg ha−1 of forage, without impacting subsequent corn silage yield. The relative feed values of triticale and wheat were 120 and 122, respectively, significantly greater than that of rye at 109. DPCCs removed 60 kg ha−1 of nitrogen (N) and 20 kg ha−1 of phosphorus (P) on average at harvest; this removal is important for nutrient management in manured systems with high P levels. The results of this experiment suggested that in addition to capturing nutrients from the fall manure application, DPCCs captured nutrients already present in the soil. The DPCC residue left in the field after harvest represented 46% of the total plant biomass, and returned 1.6 Mg ha−1 of carbon. Decomposition trends of DPCCs demonstrated nitrogen immobilization dynamics. Twenty percent of all the residual nitrogen was released in the first week after termination. The residual biomass continued to decompose, but the nitrogen decomposition was arrested. While, in this study, corn yields were not impeded, our findings demonstrated the potential to affect the fertility needs of corn in a multi-year rotation.

Cost Assessment of Centralizing Swine Manure and Corn Stover Co-Digestion Systems

Livestock in the state of Iowa, United States (US) produce over 50 × 106 Mg of wet-basis manure yearly. Biogas production from manure’s anaerobic digestion (AD) can reduce greenhouse gas emissions, control odors, and provide renewable energy. Despite these benefits, AD is rarely deployed at swine farms in Iowa. In this work, we explore the economics of AD systems in Iowa to evaluate reasons for low deployment and explore the production cost impacts of biogas cleaning and injection into the natural gas grid, amending manure with biomass, and centralizing digesters across multiple farms. This work presents a static, spreadsheet-based technoeconomic model that embodies literature-based estimates of key system technical parameters, costs, and transportation fuel incentives and permits the examination of various scenarios. Key findings include that under the model assumptions, distributed, farm-scale digesters are not competitive with average natural gas prices in Iowa. A centralized production scenario can be competitive, provided that programs such as the low-carbon fuel standard (LCFS) and the renewable fuel standard (RFS) have sufficiently high credit values.

Nutrient recovery in cultured meat systems: Impacts on cost and sustainability metrics.

A growing global meat demand requires a decrease in the environmental impacts of meat production. Cultured meat (CM) can potentially address multiple challenges facing animal agriculture, including those related to animal welfare and environmental impacts, but existing cost analyses suggest it is hard for CM to match the relatively low costs of conventionally produced meat. This study analyzes literature reports to contextualize CM's protein and calorie use efficiencies, comparing CM to animal meat products' feed conversion ratios, areal productivities, and nitrogen management. Our analyses show that CM has greater protein and energy areal productivities than conventional meat products, and that waste nitrogen from spent media is critical to CM surpassing the nitrogen use efficiency of meat produced in swine and broiler land-applied manure systems. The CM nutrient management costs, arising from wastewater treatment and land application, are estimated to be more expensive than in conventional meat production. Overall, this study demonstrates that nitrogen management will be a key aspect of sustainability in CM production, as it is in conventional meat systems.

Water storage and use efficiencies of rainfed winter wheat-summer green manure systems of the US Southern Great Plains

Conservation practices such as green manures and no-tillage can reduce soil erosion, enhance soil biological activity, increase water storage in soils, and provide nitrogen (N) in support of winter wheat (Triticum aestivum L.). However, green manures utilize soil water during the summer months, and such water depletion may negatively impact production by wheat in ecoregions with limited water resources. This 5-year study quantified the impacts of tillage systems and green manures on water storage efficiency (WSE) during summer, water use efficiency (WUE), and grain yield of winter wheat. The study was conducted during 2011–2016 in the United States (US) Southern Great Plains (SGP). Three legumes as green manures (cowpea, pigeon pea, and soybean) were compared with summer fallow and three levels of applied inorganic N (0, 45 and 90 kg N ha-1) at wheat planting, under conventional and no-till cultivation. Summer WSE was significantly (P < 0.05) reduced in response to green manures; summer fallow was also inefficient in storing soil water. Grain yield and WUE of wheat were reduced in response to green manures compared to summer fallow during dry years but there were no differences during wet or normal rainfall years. No till significantly increased WSE under all treatments, and reduced evapotranspiration during a subset (either summer or wheat growing season) of years but did not affect amounts of soil water. Our results demonstrate replacing summer fallow in continuous systems of winter wheat with green manures have limited effects on improving water availability or efficiencies in water use by wheat. More-effective approaches for using green manures to support winter wheat in the SGP include opportunity cropping during years with adequate moisture to support double-cropping or utilizing more water-efficient legumes or cropping systems.

Продуктивность севооборота в зависимости от систем применения удобрений в длительном опыте

The problem of increasing soil fertility is one of the main tasks of agriculture in the Udmurt Republic and the Non-Chernozem region. The most acceptable way of solving this problem is biologisation, which provides for a decrease in the amount of chemicals and an increase in the amount of biologicalagents. If there is a lack of fertiliser, the use of green manure or straw alone will not solve the problem. On acidic soils, a complex action on the soil is needed, starting with liming and the use of optimal doses of mineral fertiliser, which help to increase land productivity and crop rotation in a short period of time. Since 1971, the Udmurt Research Institute of Agriculture has been studying different fertilizer systems in 8-field crop rotations (1 – fallow; 2 – winter rye; 3 – potato, corn; 4 – spring wheat; 5 – clover; 6 – clover; 7 – winter rye; 8 – barley). Factor A are backgrounds: 0 – “zero” [10]; I2 – lime per one hydrolytic acidity (4.9 t/ha CaCO3) in the first rotation + two hydrolytic acidities (7.5 t/ha) in the second rotation; Н5С – manure 40 (first rotation) + 60 t/ha (2d‑5th rotations) + green manure (6th rotation); L2M5GM – lime + manure + green manure similarly. Factor B are options. Options without fertiliser and NPK are considered. Lime reduced soil acidity to a neutral level, slightly increased in the 4th rotation. The content of P2O5, K2O, and humus reached the highest level in the 5th rotation on manured backgrounds, resulting in 3.23 and 3.31 tce/ha in six rotations (18.3 and 22.0% more than without fertiliser). In lime and manure systems, mineral fertiliser increased crop rotation productivity by 32.4–35.7% on average over the entire period. Optimal doses for 3.0–4.0 t grain units/ha were 40–50 kg NPK/ha. Reducing the doses from 40–60 to 10–30 kg/ha of NPK in the last two rotations led to a decrease in crop rotation productivity (2.74–2.84) by 0.41–0.49 t grain units /ha. The lime-organomineral fertiliser system in the 3d, 4th and 5th rotations with “the addition of micronutrient fertiliser (zinc for winter rye, cobalt for potatoes, copper for spring wheat and barley, boron and molybdenum for clover)” [9] provided the highest crop rotation productivity – 4.67; 4.25; 3.32 t grain units/ha, with the highest increases – 2.05; 1.12; 1.05 t grain units/ha or 78.2; 35.8; 46.2%, respectively, in rotations. Manure can only be replaced periodically with a pea-oat mixture.

Effect of Mechanical Solids Separators on Potential Reduction of Methane Emissions From Dairy Manure Storage

Highlights Four mechanical manure separators were evaluated in on-farm studies. Mass balances and biochemical methane potential tests were conducted to measure on-farm separation efficiencies. Separator performance depended on environmental, material, and design factors. Over 70% solids separation and methane emission reduction potentials were achieved. Abstract. The separation efficiencies of four mechanical solid-liquid separation technologies and their effect on the reduction of methane production potential from dairy lagoons were studied using on-farm separator measurements and laboratory biomethane potential tests. The studied technologies included 1-stage sloped dual-screen, 2-stage sloped dual-screen, 1-stage horizontal scraped screen, and 1-stage sloped single-screen separators. The technologies were evaluated across various seasons on four dairies in California. On-farm sampling and measurements of the influent of flushed manure and the mass of the solids separated, as well as in-laboratory measurements of methane (CH4) production potential, were carried out. A mass balance approach was employed to determine the removal efficiencies of total and volatile solids (TS and VS) and nutrients, as well as methane emission reduction potential. The performance of the separators depended on manure characteristics, system design (e.g., screen size and orientation), separator operation and management (e.g., manure flow rate), and manure processing pit type and configuration. Among the four studied separator systems, the 2-stage sloped dual-screen separator showed the highest average TS and VS removal efficiencies, and methane emission potential reduction of 52.5%, 59.7%, and 55.8%, respectively. The 1-stage horizontal scraped screen separator had the lowest TS and VS removal efficiencies, and methane emission reduction potential of 6.3%, 9.3%, and 4.9%, respectively. The results have potential implications for nutrient and greenhouse gas management strategies and/or policies in agriculture. Keywords: Greenhouse gas, Lagoon, Manure management, Separation efficiency, Settling basin, Solid-liquid separation, Sustainable agriculture.

Effects of sustainable agronomic intensification in a forage production system of perennial grass and silage corn on nutritive value and predicted milk production of dairy cattle.

The objectives were to determine the effects of incrementally applied improved nutrient management, alternative cropping practices, and advanced production technologies in a dual forage system of perennial grass and silage corn on nutrient composition and in vitro ruminal fiber digestibility of the forages and, using these data as inputs into the Cornell Net Carbohydrate and Protein System, to predict milk production, indicators of nitrogen (N) utilization, and N excretion of dairy cattle. Farm management systems (farmlets) included a conventional system with whole manure slurry broadcast to a late maturing corn hybrid and grass harvested with 5 cuts per year (F1); improved nutrient management with a separated manure system where the sludge was applied to corn and the liquid was applied to grass (F2); improved nutrient management and alternative cropping practices with separated manure, an early maturing corn hybrid interseeded with a relay winter cover crop, and grass harvested with 3 cuts per year (F3); and improved nutrient management and alternative cropping practices combined with advanced production technologies that included irrigation and a nitrification inhibitor (F4). The field trial was a randomized complete block design over 2 yr with 4 blocks each divided into grass and corn, 4 subplots within each block for each crop, and 2 replicates within each subplot. Diets were formulation with 60% forage and 40% concentrate where the grass and corn as silage was proportional to yield for land allocations of grass and corn of 80:20, 60:40, 40:60, and 20:80. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc.). The intensified management systems (F2, F3, and F4) increased the crude protein (CP) concentration of corn with no effects on starch concentration [32.1% dry matter (DM)] compared with the conventional system (F1). Decreasing cuts of grass from 5 to 3 reduced the CP concentration in the spring harvest (15.8% vs. 12.5% DM), and increased fiber concentration and reduced digestibility in the spring, summer, and fall harvests. A common concentrate was formulated for the conventional farmlet and then combined with the forages for each farmlet within each land allocation. Forages grown under intensified management to improve N capture increased the CP concentration of the diets. However, reducing the number of cuts of grass from 5 to 3, combined with the corn and relay crop to increase yield, reduced milk production across all land allocations. To complement the nutritive value of the forages grown under each management system and land allocation, the concentrates were reformulated, which reduced dietary CP, improved the indicators of N utilization (e.g., milk urea N and milk N efficiency), reduced N excretion, and improved milk yield with no differences among the farmlets. Increasing land allocated to corn supported higher milk yield at lower dietary CP concentrations (16.5% vs. 15.4% DM) with improved milk N efficiency and lower N excretion. Intensified agronomic management increased the CP of the combined forages decreasing the need for supplemental CP in the concentrate and could reduce the importation of feed N to the farm.

Maize response to nitrogen and phosphorus starter fertilisation in mineral-fertilised or manured systems

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 and 250 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 2019 was 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.

Potential application of urease and nitrification inhibitors to mitigate emissions from the livestock sector: a review.

Human activities have caused an increase in greenhouse gas emissions, resulting in climate change that affects many factors of human life including its effect on water and food quality in certain areas with implications for human health. CH4 and N2O are known as potent non-CO2 GHGs. The livestock industry contributes to direct emissions of CH4 (38.24%) and N2O (6.70%) through enteric fermentation and manure treatment, as well as indirect N2O emissions via NH3 volatilization. NH3 is also a secondary precursor of particulate matter. Several approaches have been proposed to address this issue, including dietary management, manure treatment, and the possibility of inhibitor usage. Inhibitors, including urease and nitrification inhibitors, are widely used in agricultural fields. The use of urease and nitrification inhibitors is known to be effective in reducing nitrogen loss from agricultural soil in the form of NH3 and N2O and can further reduce CH4 as a side effect. However, the effectiveness of inhibitors in livestock manure systems has not yet been explored. This review discusses the potential of inhibitor usage, specifically of N-(n-butyl) thiophosphoric triamide, dicyandiamide, and 3,4-dimethylpyrazole phosphate, to reduce emissions from livestock manure. This review focuses on the application of inhibitors to manure, as well as the association of these inhibitors with health, toxicity, and economic benefits.

Manure management strategies are interconnected with complexity across U.S. dairy farms.

Among one of the key challenges in dairy production is the management of manure in a way that is beneficial for agricultural production, with minimal environmental and public health impacts. Manure management systems (MMS)—the entire system of handling, storage, and application of manure—are diverse in countries with developed dairy industries such as the United States, enabled by a number of different technologies. The ways in which dairy farmers manage manure is driven by varying tradeoffs, including economic, social, and environmental; however, existing research has not examined the relationships between components of MMS. Here we use data from the National Animal Health Monitoring System’s Dairy 2014 study to explore the ways in which manure handling, storage, and application are related, using a series of logistic regression models and network associations. We found significant associations between how manure is handled, stored, and applied, especially driven by the consistency of manure. For solid manure, we found highly heterogeneous systems, where farmers may have a suite of alternative manure management strategies available to them, and substitution is viable. Conversely, farms using liquid manure systems have very few substitutes in their MMS, suggesting greater investment in certain infrastructures, which are not easily changed. Such findings have important implications for shifting farmers towards management practices with minimal environmental and public health impacts, demonstrating that not all farm systems are easily changed. We highlight these results in light of current policies, which may not fully capture the relationships across the MMS, and suggest that greater financing may be necessary to shift MMS on some farms. Furthermore, we suggest that different MMS have varying tradeoffs across environmental, social, and economic aspects, which demonstrates that MMS are highly individualized to a given farm’s goals and priorities.

Single and multi-component removal of natural hormones from aqueous solutions using soybean hull

The presence of natural hormones in water resources has gained considerable attention in recent years due to their capacity to cause imbalances in several biological systems. Studies have shown that estrone (E1), 17β-estradiol (E2), and estriol (E3) have a high contamination potential even in low concentrations. Thus, new methods are needed to remove these contaminants directly at the source. The present study evaluated the use of the in natura soybean hull as a biosorbent for the removal of estrone (E1), 17β-estradiol (E2), and estriol (E3) from swine manure, using single and multi-component systems. Best hormone removal conditions were performed at room temperature (25 °C) with no pH adjustment. Equilibrium for a single component (SC) and multi-component (MC) systems was reached in 1 h for E1 and 2 h for E2 and E3, and the kinetics were well described by the pseudo-first-order model. Ternary equilibrium models indicated that there was no competition among the hormones. For the MC system, Langmuir model showed maximum adsorption capacities of 2.560 mg g−1, 1.978 mg g−1 and 0.835 mg g−1 for E1, E2, and E3, respectively. Thermodynamic analysis indicated that the adsorption was favorable and spontaneous with physisorption characteristics. The hydrogen-bonding represented the primary adsorption mechanism between the hormones and the adsorbent. The in natura soybean hulls, used as an adsorbent, showed to be promising for removing hormones present in the biofertilizer (swine manure), with characteristics that allow the adsorbent to remain together with the biofertilizer at its final destination. Therefore, an environmentally friendly technology.