Location: Adaptive Cropping Systems Laboratory
2021 Annual Report
Objectives
Objective 1: Develop strategies using cover cropping and biosolids management to mitigate green-house gas (GHG) emissions and improve soil health.
1.A) Evaluate soil carbon (C) sequestration with cover crops to mitigate GHG emissions.
1.B) Evaluate the ability of biosolids management strategies to sequester C and thereby reduce GHG emissions.
Objective 2: Develop strategies for managing fertilizer-N in cropping systems and manure NH3-N in high-residue tillage systems, to improve N-use efficiency and air quality.
2.A) Conduct field crop research with a corn-wheat-soybean rotation to evaluate 15N uptake efficiencies of genetically modified corn, conservation of N by cover crops, and soybean N2 fixation.
2.B) Evaluate and develop best management practices for reducing ammonia volatilization and to estimate ammonia losses from manures.
Objective 3: Improve descriptions of biological mechanisms controlling bioactive P release to soils, and develop improved fate models and conservation practices to enhance P use efficiency.
3.A) Evaluate nutrient conservation practices based on enhanced understanding of rhizosphere microbiology and enzymology that regulate the release of bioactive manure-P and soil-P to crops and soil.
3.B) Evaluate relevance of current algorithms in use to include rhizosphere microbiology and enzymology processes when modeling P behavior and transport in APEX and similar models.
Objective 4: Develop beneficial uses of agricultural, industrial, and municipal byproducts to enhance crop production and reduce risks to the environment from potential contaminants.
4.A) Conduct phytostabilization research using mixtures of organic resources with byproducts and alkaline amendments to achieve functional remediation and revegetation of barren and biologically dead metal contaminated soils.
4.B) Conduct phytoextraction/phytomining research to identify effective plant species and optimize the agronomic productivity of phytoextraction technologies.
4.C) Conduct research and risk evaluation to assess the risks and benefits from use of industrial, municipal and agricultural byproducts to improve crop production and reduce risk to the environment from byproduct constituents.
4.D) Investigate the use of mixtures of organic amendments, limestone byproducts, flue gas desulfurization gypsum and leachable alkalinity to correct subsoil acidity and improve soil fertility.
Approach
Obj. 1A. A replicated six-year field experiment will be completed to evaluate the rate and quantity of carbon sequestrated by winter cover-crops of rye, hairy vetch, and a rye plus hairy vetch mixture, as compared to a traditional no-cover condition. These data will assess and develop agricultural practices for mitigating global warming.
Obj. 1B. Agricultural use of biosolids could improve soil carbon sequestration and thereby reduce greenhouse-gas emissions. Replicated field research will be conducted on plots previously treated with different rates and types of biosolids, to determine if biosolids can increase soil carbon sequestration.
Obj. 2A. Labeled nitrogen fertilizer will be used in a corn-wheat-soybean rotation to evaluate nitrogen use efficiencies of genetically modified and non-modified corn, to measure conservation of corn residual fertilizer by winter-wheat, and to estimate nitrogen fixation of double-crop soybeans. Improving nitrogen use efficiency will reduce nitrogen losses to the environment while maintaining profitability.
Obj. 2B. Ammonia volatilization is a major loss of plant-available nitrogen from surface applied manures. A series of wind tunnel field studies will be conducted to evaluate the ability of new high-residue tillage implements to conserve ammonia, but still maintain surface residues to control erosion.
Obj. 3A. Laboratory incubation-fractionation studies will be conducted to mathematically describe phosphorus transformations and availability in manured soils. These results will assess the advantages and disadvantages of adding organic-phosphorus turnover to existing models.
Obj. 3B. A critical evaluation of phosphorus transformation and transport modules within existing phosphorus models will be conducted by validation against long-term field and simulated rainfall studies. The evaluation will focus on the use of rhizosphere microbiology and enzymology for modeling phosphorus.
Obj. 4A. Two field locations will be studied using various mixtures of industrial, municipal, and agricultural byproducts to remediate and revegetate barren and heavy-metal contaminated soils. The studies will monitor plant yield and composition to assess byproduct performance and possible risks to wildlife.
Obj. 4B. Growth chamber and greenhouse research on phyto-mining will use various fertilizer nutrients and topsoil/subsoil combinations to identify plant species and management practices that optimize agronomic productivity and that extract nickel from nickel-rich soils.
Obj. 4C. A two-year field study will be conducted in Appalachia comparing the uptake of nutrients and metals by peanut and wheat from additions of poultry litter, flue gas desulfurization gypsum, and mined gypsum. A risk assessment on the use of flue gas desulfurization gypsum and mined gypsum in U.S. soils will also be done.
Obj. 4D. A greenhouse study will be conducted to evaluate mixtures of organic amendments, limestone byproducts, flue gas desulfurization gypsum, and leachable alkalinity to correct subsoil acidity for alfalfa. Subsoil acidity commonly limits rooting depth in soils across the mid-Atlantic and Southern regions of the U.S..
Progress Report
Two scientists, hired through the ORISE agreement are contributing to this work.
In support of Obj 1A, collaborated with a graduate student at the Univ. of Maryland's Department of Plant Sciences and Landscape Architecture. This research compared nitrate-nitrogen (NO3--N) leaching losses among forage radish (Raphanus sativus L.), cereal rye (Secale cereal L.), a forage radish+cereal rye mixture, and no cover control . Replicated field trials were conducted at the University of Maryland Central Maryland Research and Education Center over 2016-2018. We compared nitrate-nitrogen (NO3--N) leaching losses among forage radish (Raphanus sativus L.), cereal rye (Secale cereal L.), a forage radish+cereal rye mixture, and no cover control . We collected porewater from 60 cm below the ground surface using porous cup lysimeters following rainfall events and used NO3 --N concentrations paired with the HYDRUS 1-D soil moisture model to compare N leaching losses (in kg N ha-1) among cover crop treatments. We show that soil porewater NO3 --N concentrations were always higher (by 5x) in the no cover control compared to rye and radish+rye treatments. Overall, N leaching losses (kg N ha-1) were highest in the no cover control plots but the majority of N leaching losses in rye plots occurred during the fall while the majority of radish N leaching losses occurred during the winter and spring (after they winter-killed). The radish+rye mixtures reduced N leaching losses by 80% in both years regardless of radish planting date. A manuscript was submitted for publication.
In support of Objectives 1 and 2, a study on the response of soybean early-maturing soybean varieties to heat stress, water availability, and CO2 was also conducted in Soil Plant Atmoshpere Research (SPAR) facilities to quantify the effects on grain yield, development, and gas exchange processes suitable for addressing climate change knowledge gaps and evaluating existing modeling tools. This was complemented by in indoor growth chambers experiments designed to evaluate the influence of air temperature and photoperiod, that correspond to regional differences in the U.S., on different soybean maturity groups. Responses to temperatures ranging from 22 to 40 degrees Celsius and photoperiods from 12 to 14.5 hours were studied. Longer photoperiods did not affect flowering time for early maturing varieties, but cooler temperatures delayed germination rate and prolonged vegetative stage. Flowering was induced earlier with shorter photoperiods in later maturing varieties, while cold temperatures exerted the opposite effect.
In support of Objectives 4C and 4D, a multi-year field experiment, evaluated the effect of poultry litter /organic fertilizer applications on the yield and trace metal content as well as nutrient uptake of three perennial seasonal forages. The objective of the study was to examine the suitability of the Stinging Nettle (Urtica dioica L.), an alternative forage crop, to two traditional warm season forages, the Bermudagrass and the Switchgrass. All the necessary field samples such as soil, plant, and water, were collected and analyzed in the laboratory. The results indicated that the stinging nettles provided a significantly higher yield than the warm season forages by 79% and 45% over switchgrass and bermudagrass for the first cool season while the warm season forages were 66% with switchgrass and 49% with bermudagrass better at their peak. The recovery of nutrients was also higher with the nettles for the two seasons indicating the propensity of the nettles as a versatile resource for animal feeds and environmental sustainability, particularly when it is double cropped with a warm season forage.
The research also assessed the role of forage crops in the remediation of nitrates emanating from agricultural lands that have received poultry litter. Depending on the soil type and amendments, soil test phosphorus (P) and nitrates in poultry litter might still negatively impact surface water quality. Therefore, there is a need for proper monitoring of the soil when using amendments, including the importance of cropping warm season forages with cool season forage crops.
Prepared two manuscripts that were submitted to the Journal of Plant Nutrition and Communications in Soil Science and Plant Analysis. Both manuscripts were accepted and published.
Accomplishments
1. Growing Radish+rye together as cover crops reduces nitrogen leaching more than when grown independently. The 2025 goal of the Chesapeake Bay Program is to reduce agriculture's nitrogen (N) loading by 20% from 2014 values. The reduction of N leaching by winter cover crops depends mainly on precipitation, the timing of planting, and the selection of the appropriate crop species. We compared nitrate-nitrogen (NO3--N) leaching losses among forage radish, cereal rye, a forage radish+cereal rye mixture, and no cover control. Overall, N leaching losses (kg N ha-1) were highest in the no-cover control plots, but the majority of N leaching losses in rye plots occurred during the fall while the majority of radish N leaching losses occurred during the winter and spring after winter-killing. The radish and rye mixtures reduced N leaching losses by 80 percent in both years regardless of radish planting date, indicating a flexible management tool to minimize leaching losses from cash crop systems. Understanding how cover crop species affect N leaching losses can help us design cropping systems to reduce N losses to the Chesapeake Bay.
2. Application of biosolids from wastewater treatment facilities are used to improve soil physical and chemical properties. ARS scientists at Beltsville, Maryland, determined that biosolids' application on soil chemical properties and heavy metal content in soils from two regions in the United States. Little difference was observed in soil acidity and salinity between surface soils with and without biosolids application at one region. It was concluded that heavy metal levels were within the standards for residential occupation with the 40 Code of Federal Regulations (CFR) Part 503 and should not affect soil and groundwater quality.
Review Publications
Codling, E., Jaja, N., Adewunmi, W., Evanylo, G.K. 2021. Residual effects of long-term biosolids application on carbon, cadmium, copper, lead and zinc in soils from two regions of the United States. Communications in Soil Science and Plant Analysis. https://doi.org/10.1080/00103624.2020.1869772.
Bronson, K.F., Hunsaker, D.J., Meisinger, J.J., Rockholt, S.M., Thorp, K.R., Conley, M.M., Williams, C.F., Norton, E.R., Barnes, E.M. 2019. Improving nitrogen fertilizer use efficiency in subsurface drip-irrigated cotton in the desert southwest. Soil Science Society of America Journal. 83(6):1712-1721. https://doi.org/10.2136/sssaj2019.07.0210.
Fernandez-Baca, C.P., McClung, A.M., Edwards, J., Codling, E.E., Reddy, V., Barnaby, J.Y. 2021. Grain inorganic arsenic content in rice managed through targeted introgressions and irrigation management. Frontiers in Plant Science. https://doi.org/10.3389/fpls.2020.612054.
Fernandez-Baca, C.P., Rivers, A.R., Kim, W., McClung, A.M., Roberts, D.P., Reddy, V., Barnaby, J.Y. 2021. Changes in rhizosphere soil microbial communities across plant developmental stages of high and low methane emitting rice genotypes. Soil Biology and Biochemistry. http://doi.org/10.1016/j.soilbio.2021.108233.
Marcillo, G.S., Mirsky, S.B., Aurelie, P., Reberg-Horton, S., Timlin, D.J., Schomberg, H.H., Ramos, P. 2020. Using statistical learning algorithms to predict cover crop biomass and nitrogen content. Agronomy Journal. 112(6):4898-4913. https://doi.org/10.1002/agj2.20429.
Thapa, R., Tully, K.L., Cabrera, M.L., Dann, C., Schomberg, H.H., Timlin, D.J., Gaskin, J., Reberg-Horton, C., Davis, B.W., Mirsky, S.B. 2021. Effects of moisture and temperature on C and N mineralization from surface-applied cover crop residues. Biology and Fertility of Soils. 57:485-498. https://doi.org/10.1007/s00374-021-01543-7.
