Location: Genetics and Sustainable Agriculture Research
2018 Annual Report
Objectives
Obj 1. Develop ecological and sustainable site-specific agriculture systems, for cotton, corn, wheat, and soybean rotations. 1: Geographical coordinates constitutes necessary and sufficient cornerstone required to define, develop and implement ecological/sustainable agricultural systems. 2: Develop methods of variable-rate manure application based on soil organic matter (SOM), apparent electrical conductivity, elevation, or crop yield maps. 3: Relate SOM, electrical conductivity, and elevation.
Obj 2. Develop sustainable and scalable practices for site-specific integration of animal agriculture byproducts to improve food, feed, fiber, and feedstock production systems. 1: Quantify effects of management on sustainability for sweet potato. 2: Balance soil phosphorus (P)/micro–nutrients using broiler litter/flue gas desulfurization (FGD) gypsum. 3: Effects of site-specific broiler litter applications. 4: Manure application/crop management practices in southern U.S. 5: Compare banded/broadcast litter applications in corn. 6: Develop reflectance algorithms for potassium in wheat. 7: Determine swine mortality compost value in small farm vegetable production.
Obj 3. Analyze the economics of production practices for site-specific integration of animal agriculture byproducts to identify practices that are economically sustainable, scalable, and that increase competitiveness and profitability of production systems. 1: Evaluate economics of on-farm resource utilization in the south.
Obj 4. Determine the environmental effects in soil, water, and air from site-specific integration of animal agricultural and industrial byproducts into production practices to estimate risks and benefits from byproduct nutrients, microbes, and management practices. 1: Quantitatively determine bioaerosol transport. 2: Role of P and nitrogen (N) immobilizing agents in corn production. 3: Assess impact of management on water sources. 1: Quantitatively determine bioaerosol transport. 2: Role of P and nitrogen (N) immobilizing agents in corn production. 3: Assess impact of management on water sources. 4: Impact of FGD gypsum/rainfall on mobilization of organic carbon/veterinary pharmaceutical compounds in runoff/leached water. 5-10.....
Obj 5. Integrate research data into regional and national databases and statistical models to improve competitiveness and sustainability of farming practices. 1: Develop broiler house emission models. 2: Apply quantitative microbial risk assessment models to animal agriculture/anthropogenic activities.
Obj 6. Develop statistical approaches to integrate and analyze large and diverse spatial and temporal geo-referenced data sets derived from crop production systems that include ecological and natural resource based inputs. 1: Develop novel methods of imaging processing.
Obj 7: Develop advanced UAS/UAV application systems and data management systems and Bioinformatics tools that integrate developed GxExM data into precision agricultural crop management for Mid-South crops. The systems and tools should lead to improvements in agricultural productivity and agricultural system landscape management.
Approach
Multidisciplinary approaches will be utilized in developing sustainable and competitive agricultural practices for crop management systems. Some approaches will use animal, municipal, and industrial waste as fertilizers and organic soil amendments in crop management systems in precision agriculture ways. Presence, prevalence, and fate of nutrients, gaseous emissions, bacterial approaches, and antibiotic resistance associated with these wastes when applied to soils in cropping systems will be addressed. Work will be done in cooperator animal feeding operations (AFO), farms, and experiment station plots. Off-site transport of nutrients, pathogens, and antibiotic resistant bacteria will be determined. Statistical models will be developed for geo-referenced measurements of farming practices and improvements to mixed model analysis methodology will be developed. Remotely sensed data will be combined with on-site field measurements to develop site-specific prescriptions for application of crop management inputs. Information will be developed into best management practices to protect the environment and human and animal health by maximizing crop nutrient utilization, minimizing bacterial contamination and antibiotic resistance, and reducing ammonia and greenhouse gas emissions. Agricultural models will be used to predict sustainability and competitiveness of management practices developed and implemented into best management practice recommendations.
Improved decision support tools and technologies based on GxExM will be developed to optimize crop production for better and more sustainable yields in the humid Southeast Agroecosystems. Techniques that utilize and integrate high resolution spectral images for in-season crop management in cropping systems and fields characterized by high soil variability will be developed. Databases, modeling tools, and decision-making paradigms for optimizing and managing, precision application of crop inputs, and crop yield will be developed and utilized. Bioinformatics approach will expand technologies applicable to the Southeastern Agroecosystems by direct and associated investigations of G x E x M interactions in part enabled by data generated by the UAS/UAV research and molecular approaches to soil bioinformatics and the soil microbiome. All these activities will be designed to improve sustainability of crop production in the humid Southeastern Agroecosystem.
Progress Report
This is the final report of project 6064-21610-010-00D. It will be replaced by a new project, "Closing the Yield Gap of Cotton, Corn, and Soybean in the Humid Southeast with More Sustainable Cropping Systems," after completion of research review.
Aerosol samples collected from downwind of swine effluent and poultry litter land application in the previous years where chicken litter was being applied were evaluated for endotoxin (e.g. bacterial lipopolysaccharide). Additionally, archived samples were preliminarily analyzed for pathogen and antibiotic resistance genes using quantitative polymerase chain reaction. Corresponding source litter and swine manure effluent were also investigated for endotoxin and associated genes.
Water, soil, and fecal samples were collected from a research farm with 3 to 14 feral hogs located on site. Feral hog impact was further assessed from the previous cultivated indicator and pathogenic bacterial analyses to include antibiotic resistance phenotypic analysis as well as deoxyribose nucleic acid (DNA) based quantitative polymerase chain reaction for antibiotic resistance genes. These analyses were performed on isolates of E. (Eschevichia) coli and enterococci, and on immediate runoff released from the paddock, respectively. Additionally, source fecal material from the feral hogs were analyzed for the presence of source pathogen and antibiotic resistance genes. Water samples were also collected from 3 separate sub watershed locations in the Mississippi Delta as well as from a large cooperator farm to continue monitoring agriculture impact on watersheds.
Four-year retrospective samples were collected from field plots previously applied with swine effluent, class B biosolids, or poultry litter. Samples have been analyzed for the presence of residual antibiotic resistance and pathogen genes following four years of no land application to determine the persistence of antibiotic resistance genes and ultimately the return to pre-application levels.
Quantitative microbial risk assessments have been conducted on previously collected soil data from small field plots with either animal or municipal waste. Aerosol data was deemed too sporadic to conduct a proper risk assessment. Risk assessments using newly published inactivation rates for molecular and cultivated data will be conducted. Antibiotic resistance gene data was uploaded to the Agriculture Antibiotic Resistance (AgAR) database as part of the initial release of data.
The effect of timing and agronomic rates of bio-solid relative to broiler litter application on cotton growth, yield and soil microbial ecology in the presence and absence of winter wheat cover crop residue are being evaluated. Soil samples are being taken every two weeks during cotton growing season and analyzed for soil enzyme activity and available nitrogen. Plant growth include height, leaf area, chlorophyll content and biomass are being determined during cotton growing season.
In a conventional tillage system the impact of biochar and lignite on poultry litter derived-nitrogen (N) and phosphorus (P) retention and their availability for cotton are being evaluated. Cotton growth measurements include height, leaf area, chlorophyll content and biomass are being determined during cotton growing season. Soil samples are being taken from biochar plus broiler litter treatment every month during cotton growing season and are being analyzed for P and N bioavailability as compared to Broiler litter only.
In a land-leveled soil, the impact of biosolid and broiler litter either alone or in combination with wood compost, a high carbon (C) by-product with a C/Nitrogen (N) ratio of 400, on soil properties and cotton performance are being evaluated.
The effects of cover crop and tillage systems on cotton responses to organic and inorganic fertilization are being evaluated. Cotton performance indicators are being measured during growing season.
In an upland soil using rainfall simulation, the impact of flue gas desulfurization (FGD) gypsum on the dynamics of poultry manure-derived-N and P in a no-till cotton field in the presence and absence of cover crop (mixed cereal rye and crimson clover) are being evaluated. Suction cup lysimeters were installed after planting cotton, leachate water samples are being collected after each rain event and the effect of treatments on soil water and nutrient holding capacity by measuring leachate volume and leaching losses of N and P are being evaluated. Cotton growth include leaf area index, plant height, leaf chlorophyll content, N recovery and final yield are also being investigated.
The relationship between leaf reflectance at specific wavelengths and potassium (K) deficiency in wheat. Photosynthesis is decreased under either K or N deficiency. But unlike remote sensing of plant N status, K-deficient plants have few if any sensitive spectral indicators of physiological stress. Results from greenhouse studies did not support our hypothesis that leaf reflectance in narrow wavelength is related to changes in K concentration across different rates of K fertilization. Measurements of reflectance (R) at 655nm and transmittance (T) were made on intact leaves at 133 wavelengths in the visible and near-infrared regions. Data analysis indicated a weak correlation between changes in leaf K concentration and either R655 (r2 = 0.21) or a single-band reflectance ratio R655/R380 (r2 = 0.24). A relatively strong correlation was obtained between leaf chlorophyll and either R705 (r2 = 0.66) or R705/R415 (r2 = 0.74). Results suggest remote sensing of K stress in wheat will require wavelengths separate from those used to detect N stress.
Continued a study measuring the value of poultry litter applied by subsurface banding versus surface broadcasting for cotton production. Non-irrigated cotton was grown with 0 to 5 ton/acre poultry litter applied by surface broadcast versus subsurface bands and with 0 to 120 pounds per acre synthetic N fertilizer. Data collected included lint yield, leaf area and chlorophyll indices, and leaf nutrient content. Preliminary results show that leaf Mn levels were elevated by synthetic N fertilization in direct proportion of the N level applied. Poultry litter, on the other hand, did not elevate leaf Mn level regardless of the amount if applied by surface broadcast but not if applied in subsurface bands. This may be attributed to a difference in the level of litter-to-soil contact (much less soil-to-litter contact if applied in bands). Cotton plants grew taller and larger in proportion of the litter rate applied by either method, but lint yield was best when the litter was applied in subsurface bands. Cotton produced 9% more lint yield with 28% less litter if applied by subsurface banding relative to surface broadcasting.
Continued investigating the benefit of winter cover crop, no-tillage, and poultry litter applied in the fall to corn production in a heavy Mississippi Delta soil. The study compared winter cover crop versus no cover crop, no-till versus conventional till, and fall versus spring-applied poultry litter on a 40-acre corn field at the Delta Conservation Demonstration Center near Metcalfe, Mississippi. Data collected included grain yield, grain and soil nutrient content, ear and grain size, ear-leaf nutrient content, and leaf chlorophyll index. Preliminary results indicate that, in the presence of cover crop, fertilizing corn with poultry litter produced 16% more grain yield than fertilizing with conventional synthetic fertilizers. No yield differences occurred in the absence of cover crop. Poultry litter enhanced corn potassium (K) nutrition but depressed the level of magnesium (Mg), iron (Fe), zinc (Zn), and manganese (Mn) in leaves which may be associated with its effect on soil pH increases of up to 0.3 units.
In a forage-based system leachate water sample are being collected after each rain event, analyzed, and the role of industrial by-product [lignite and flue gas desulfurization (FGD) gypsum] on leaching losses of residual poultry manure-derived Phosphorus are being evaluated.
A Factsheet for solar-electric stand-alone installations at broiler farms is completed and is ready for submission to the public via Livestock GRACEnet website. As of 2018, the published manuscript (Brinson case study) is featured on Eagle Green Energy’s website (eaglegreenenergyinc.com). Data analysis is underway for swine mortality composts to determine the effect of readily available additives [flue gas desulfurization (FDG) gypsum and Poultry Litter Treatment®] and forced aeration on the composting process and retention of nitrogen in the final compost product. Manuscript was published describing the culmination of a decade of litter/gas studies. It will be included in the broiler litter characterization data base, which is being developed. Ongoing research finds best management practices to minimize greenhouse gas (GHG) emissions from soil in corn/cotton farming with three years of data entered into template and submitted to the GRACEnet database.
Accomplishments
1. Feral hogs don’t contribute to antibiotic resistance in water. Feral hogs have caused farmer crop losses as well as ecological damage as the hogs have expanded their territory in recent years. ARS researchers at Mississippi State, Mississippi, in conjunction with researchers from Mississippi State University conducted a 1-year study to determine the effect of feral hogs on surface water, specifically nutrient, pathogens, and antibiotic resistance. Various pathogens were investigated including Salmonella, Campylobacter, and Eschevricia (E.) coli, as well as antibiotic resistance genes such as resistance to tetracycline and erythromycin following rain events. Overall, the data suggests limited impact by feral hogs on antibiotic resistance, but direct access to streams may increase pathogen and indicator bacterial loads. Feral hog fecal matter was at or below detectable limits for antibiotic resistance genes, especially when compared to commercial swine farm manure, suggesting that feral hogs don’t harbor resistance, at least for the studied genes and organisms. The study did demonstrate variability in fecal contamination in stream and suggests that further study is needed to determine contributions to the soil or water resistome.
2. Integration of poultry litter into cover crop in no-till cotton field improve soil health. Upland soils are generally low in inherent nutrient content, marginal in organic matter, vulnerable to erosion and nutrient losses which are negatively affect crop production. Inclusion of cover crops may be a potential strategy to boost no-till performance by improving soil physical properties, yet support for these claims within Mississippi remains limited, and more information is needed to elucidate cover crop feasibility and benefits to encourage adoption in the state. ARS researchers at Mississippi State, Mississippi, investigated the effects of cover crop along with broiler litter fertilization on cotton performance and soil health. Addition of cover crop not only had the best potential as nitrogen (N) scavenger but also improved soil physical properties by reducing bulk density, enhancing infiltration and hydraulic conductivity. Integration of cover crop and poultry litter induced change in soil organic Carbon (C) concentration which was positively correlated with soil physical properties. Results from this study will contribute valuable information for farmers and stakeholders regarding the feasibility of cover cropping and the potential benefits attainable within the Mid-South United States agro-ecosystem.
3. Gypsum-treated poultry manure reduces phosphorus in leachate. Loss of phosphorus (P) by leaching is an important issue, especially on agricultural fields with subsurface tile drainage. Since the poultry manure nitrogen/phosphorus (N/P) ratio is smaller than plant N/P uptake, repeated applications of poultry manure based on nitrogen (N) need of crops results in buildup of excess P in the soil which is an environmental concern since it acts as a continuing source of soluble P. This form of P is contributing to accelerated eutrophication of water bodies. Adding flue gas desulfurization (FGD) gypsum to poultry manure stabilizes P in less soluble forms. ARS researchers at Mississippi State, Mississippi, evaluated the effects of FGD treated versus untreated poultry manure on P leaching from bermuda grass plots receiving long-term poultry manure applications and showed that adding FGD gypsum to poultry manure substantially reduced P concentrations in leachate/drainage. This study suggests that the addition of FGD gypsum to poultry manure when used to fertilize crops can be recommended as a best management practice to control P transport, avoid water pollution by P, provides a baseline for further environmental risk assessment associated with water pollution, and improve the sustainability of fertilizing with poultry manure.
4. Prescription-based application of poultry litter benefits cotton production. Farm soils are inherently variable. A small field may have areas of high and low soil organic matter, high and low elevations, and heavy and light soil texture. Applying the same amount of poultry litter or other manures from one end of such fields to the other leads to applying excess in some parts and not enough in others. ARS researchers at Mississippi State, Mississippi, used site-specific technology to test if applying poultry litter according to the soil organic matter (SOM) level or the field contour would improve cotton yield or reduce cost of production. A poultry litter application prescription was prepared so that high amounts were applied in parts of the field with high elevation or with low SOM and low amounts were applied in parts of the field with low elevation or high SOM. The results showed that prescription-based application targeting the need of the cotton may reduce cost of production without sacrificing yield. Cotton fertilized with litter regardless of the method produced more lint yield than cotton fertilized with conventional synthetic fertilizers. Applying the litter by varying the rate based on elevation (or SOM) where higher rates are applied at higher elevations (or lower SOM) and lower rates at lower elevations (or higher SOM) may further enhance the superiority of litter. These results are most useful for cotton farmers in the southeastern U.S. in farms with SOM and elevation variability great enough to affect production and profit.
5. Poultry litter band placement in no-till cotton affects soil nutrient conservation. Applying poultry litter in narrow subsurface bands has been shown to greatly reduce nutrient losses to water runoff from simulated rain of about 1 hour duration. Whether such short-term reductions lead to nutrient conservation on a longer-term (3 to 5 years) basis has not been well investigated. ARS researchers at Mississippi State, Mississippi; Auburn, Alabama, and Boonville, Arkansas, in cooperation with Mississippi State University scientists investigated whether poultry litter applied below versus above the soil surface in bands with narrow versus wide spacing affects the accumulation and conservation of mineral nutrients in a no-till cotton cropping system. The results showed applying poultry litter in bands below (regardless of the band-to-band spacing) rather than on the soil surface leads to greater conservation of most mineral elements which remain accessible for cotton plant uptake. However, placing the bands on the soil surface rather than below the surface was more effective in reducing soil and tissue manganese concentration, a nutrient that may decrease cotton productivity if taken up by cotton plants in excess. The results contribute to existing knowledge of the environmental and sustainability benefit of applying poultry litter in narrow bands below the soil surface.
6. Balancing bermudagrass hay quality with phosphorus removal. Producing bermudagrass hay from fields receiving poultry litter provides both high quality forage for ruminant livestock and is a means of removing environmentally sensitive nutrients, especially phosphorus (P). While growers seek a reasonable balance between high forage production and quality by cutting every 28 to 35 days, the impact of harvest management timing on controlling soil P is not widely known. ARS researchers at Mississippi State, Mississippi, and collaborators at Mississippi State University found a commonly used practice, cutting every 35 days at low stubble height, provided a reasonable balance between optimizing forage nutritive value and P removal. Cutting every 49 days at low stubble height maximized P removal at approximately 25 pounds per acre regardless of location. The knowledge is vital to a forage farm income, which is not driven by manure management, but livestock output.
7. Broiler house litter mineral content. In the United States, chicken (broiler) production supplies the most meat consumed per capita. Broilers are grown in large (50 feet by 500 feet or more) solid-sidewall barns on a layer of bedding which becomes known as litter as defecation begins and continues through the growth period. Understanding the interrelationships of house structure, litter dynamics, and bird age can reduce ammonia emissions and increase production efficiency. Once considered only a waste, litter is sought after for fertilizer and energy ventures. ARS researchers at Mississippi State, Mississippi, characterized a vast number of samples reporting actual averages and range of concentrations for litter mineral content along with spatial and temporal influences. The strategic nature of the sampling offers a resource for contributing to a whole farm production model. The poultry industry can utilize the data for improving house structure, feed and water delivery systems based on bird migration patterns during the flock. Other stakeholders include fertilizer and litter-to-energy clients. The potential impact is that comprehensive characterization leads to comprehensive utilization and more sustainable poultry production.
Review Publications
Tewolde, H., Shankle, M.W., Way, T.R., Pote, D.H., Sistani, K.R., He, Z. 2018. Poultry litter band placement affects accessibility and conservation of nutrients and cotton yield. Agronomy Journal. 110(2):675-684. https://doi.org/10.2134/agronj2017.07.0387.
Brooks, J.P., Tewolde, H., Adeli, A., Shanke, M.W., Way, T.R., Smith, R.K., Pepper, I.L. 2018. Soil microbiological impact of cover crop and fall-applied poultry litter in subsurface bands. Journal of Environmental Quality. 47(3):427-435. doi:10.2134/jeq2017.09.0382.
Tang, Q., Liu, H., Tewolde, H., Jiang, P., Lei, B., Zhai, L., Ren, T. 2018. Nitrogen uptake and transfer in broad bean and garlic strip intercropping systems. Journal of Plant Nutrition and Soil Science. 17(1):220-230. https://doi.org/10.1016/S2095-3119(17)61772-6.
Way, T.R., Kornecki, T.S., Tewolde, H. 2018. Planter closing wheel effects on cotton emergence in a conservation tillage system. Applied Engineering in Agriculture. 34(1):177-186.
Read, J.J., Lang, D., Adeli, A., Jenkins, J.N. 2018. Harvest management effects on "Tifton 44" Bermundagrass phosphorous removal and nutritive value. Agronomy Journal. 110:879-889. doi:10.2134/agronj2017.08.0480.
