Location: Grassland Soil and Water Research Laboratory
2024 Annual Report
Objectives
Objective 1: Develop and evaluate system management strategies to improve productivity and resilience of cropping systems and grazed and ungrazed grasslands.
Sub-objective 1.A: Improve agricultural systems, resilience, ecosystem services, and sustainability through manure and nutrient management practices and cropping systems in holistic and sustainable systems.
Sub-objective 1.B: Evaluation of precision agriculture for the adoption of precision nutrient applications.
Sub-objective 1.C: Grazing management to improve biomass production and soil health.
Objective 2: Investigate system-level responses of grasslands to natural and anthropogenic perturbations including extreme weather events and novel nutrient management practices.
Sub-objective 2.A: Quantify long-term effects of multiple nutrient fertilization and disturbance on productivity, species composition, and soil health in native C4 grasslands.
Sub-objective 2.B: Identify genetic control of plant traits conferring yield resilience in perennial bioenergy crops.
Objective 3: Develop, evaluate, and monitor indicators of agroecosystem productivity, sustainability, and resilience.
Sub-objective 3.A: Evaluate key indicators of resilience and sustainability across the LTAR network to evaluate soils, crop production, and environmental (i.e., water quality) outcomes.
Approach
The overall aim of this research is to improve the multifunctionality of agroecosystems while simultaneously maximizing conservation efforts. The multifunctionality of these agroecosystems include food production, natural resource services, fiber production, and other ecosystem services. Each of these systems face increasing challenges ranging from extreme weather events to a growing world population that recently exceeded eight billion. The Grassland, Soil and Water Research Laboratory (GSWRL) is well positioned to address the vast range of challenges being faced by our producers, policymakers, and stakeholders.
The researchers at GSWRL use a collaborative and interdisciplinary approach aiming to address the following research components: 1) develop and evaluate system management strategies to improve productivity and resilience of a range of agroecosystems; 2) investigate system-level responses of grasslands to natural and anthropogenic perturbations; and 3) develop, evaluate, and monitor indicators of agroecosystem productivity, sustainability, and resilience. Each of these components aim to face current and future agroecosystem challenges, while also maximizing conservation efforts for future generations of producers, consumers, and stakeholders.
The GSWRL will address these research components via field trials, laboratory analytics, mechanistic experiments, remote sensing and geospatial methodologies, and modeling. Each of the methods will take place at Texas Gulf (TG) Long-Term Agroecosystem Research (LTAR) site, located within the Texas Blackland Prairies ecoregion, but will benefit from the inclusion of other ecoregions through established collaborative efforts as well as the expanding LTAR network. Reaching across agroecoregions provides opportunity to improve the multifunctionality of agroecosystems both within and outside the Texas Blackland Prairies. Such an approach will contribute new and innovative solutions and knowledge for a myriad of agroecosystem challenges leading to conservation, sustainability, and resilience of U.S. agricultural resources.
Progress Report
Objective 1: Progress toward Objective 1 has been made through beginnings of data collection and experimental establishment among the Sub-Objectives. For instance, Sub-objective 1A has made progress through the establishment of a database to investigate manure handling standards for each state across the United States. Moreover, Sub-objective 1A has made progress through organization of soil health and active carbon experimental designs that will soon result in a draft of a manuscript for the subsequent analytics. With aims to improve water quality and decrease nitrous oxide emission, Sub-objective 1B has made great progress in establishing a plot design at two locations (Temple and Riesel) within the Texas Gulf. These plots set the foundation for the fertility studies that will aid the aims stated above. Lastly, Sub-objective 1C has made progress through the establishment of a Business As Usual (BAU) and Aspirational (ASP) design for the station’s grazing lands at the Riesel, Texas, location, establishing the foundation in which future grazing land studies will be conducted throughout the current and future project plans as well as the furtherment of Long-Term Agroecosystem Research (LTAR) data/research initiatives. It is worth noting that a new scientist has recently been onboarded who is leading the grazing land research endeavors, in which great progress has been made since their start date.
Objective 2: Progress towards Objective 2 has continued given the Nutrient Network (NutNet) and Disturbance and Resources Across Global Grassland Network (DRAGNet) being established in 2007 and 2021, respectively. Nevertheless, the experiments have been furthered in conjunction with Texas State University through progress towards the establishment of unmanned aerial vehicle (UAV) remote sensing and soil health data collection beginning/continuing in this past year (Sub-objective 2A). Moreover, the scope of these continued research projects has been expanded through focus on the effects of management practices on productivity and soil health.
Objective 3: Progress towards Objective 3 has been in conjunction with the LTAR network as the key aims of Sub-objective 3A are closely tied to the long-term agroecosystems research. Among Sub-objective 3A progress there have been great strides in coding efforts aimed to establish indicators for resilience and sustainability across various agroecosystems. Moreover, with the hiring of a new Scientist with expertise in database management, our site has made strides towards the development and enhance of our research data acquisition and storage. A noteworthy point of progress is the establishment of a site-level committee for data management that will continue regular meetings to improve data acquisition/management at our site.
Accomplishments
1. Combining sensors and models for improved irrigation scheduling. Irrigation scheduling models and soil water sensors have been separately developed as technologies to assist irrigation management decisions. However, the two technologies should ideally be integrated, because they are complimentary and can work together to provide improved recommendations. An ARS scientist at Maricopa, Arizona (now Temple, Texas) compared cotton yield and water use outcomes when managed by three irrigation scheduling models and when those models were assisted by field measurements of soil water status. The results showed that adding soil water measurements could reduce irrigation requirements by 9-21% while often maintaining cotton fiber yields. In addition to producers, several commercial industries will benefit from this research, including industries supporting agricultural irrigation, U.S. cotton production, and the development of soil water sensing equipment.
2. Establish grazing experimental design and treatments and collect baseline vegetation and soil data. Determining optimized grazing land management practices for a given ecoregion requires long-term evaluations. Extreme weather and climate events can readily affect the annual ecological structure and function of grazing lands, thus skewing short-term results. While the Great Plains have experienced a long history of regular disturbances from droughts and floods, grazing, and fires, the increased frequency and magnitude of these disturbances can reduce ecological resilience, largely depending on management practices. Alternative strategies designed to adaptively manage grazing land resources based on the ecology of the system should increase the resistance and resilience to disturbances when compared to prevailing practices. ARS scientists at Temple, Texas, have improved upon an existing long-term grazing land study that compares these prevailing (business as usual) and alternative (aspirational) strategies. The results of this research will aid in developing regenerative agricultural practices and improving ecological resistance and resilience to frequent disturbances.
Review Publications
Salem, H.M., Schott, L.R., Piaskowski, J., Chapagain, A., Yost, J.L., Brooks, E., Johnson-Maynard, J. 2024. Evaluating intra-field spatial variability for nutrient management zone delineation through geospatial techniques and multivariate analysis. Sustainability. 16(2). Article 645. https://doi.org/10.3390/su16020645.
Thorp, K.R., DeJonge, K.C., Pokoski, T., Gulati, D., Kukal, M., Farag, F., Hashem, A., Erismann, G., Baumgartner, T., Holzkaemper, A. 2024. Version 1.3.0 - pyfao56: FAO-56 evapotranspiration in Python. SoftwareX. 26. Article 101724. https://doi.org/10.1016/j.softx.2024.101724.
Yost, J.L., Kruger, K., Bjorneberg, D.L., Dungan, R.S., Leytem, A.B., Moore, A.D., Schott, L.R. 2024. Assessment of soil aggregate stability methodologies in calcareous silt loams. Journal of the ASABE. 67(4):879-887. https://doi.org/10.13031/ja.15650.
Yost, J.L., Smith, D.R., Adhikari, K., Arnold, J.G., Collins, H.P., Flynn, K.C., Hajda, C.B., Menefee, D.S., Mohanty, B.P., Schantz, M.C., Thorp, K.R., White, M.J. 2024. The LTAR cropland common experiment at the Texas Gulf. Journal of Environmental Quality. https://doi.org/10.1002/jeq2.20592.
Gyanwali, P., Khanal, R., Pokhrel, S., Adhikari, K. 2024. Exploring the benefits of biochar: A review of production methods, characteristics, and applications in soil health and environment. Egyptian Journal Soil Science. 64(3):855-884. https://doi.org/10.21608/EJSS.2024.270380.1725.
Adhikari, K., Anderson, K.R., Smith, D.R., Owens, P.R., Moore Jr., P.A., Libohova, Z. 2023. Identifying key factors controlling soil respiration in agricultural fields. Agricultural & Environmental Letters. 8(2). Article e20117. https://doi.org/10.1002/ael2.20117.
Adhikari, K., Mancini, M., Libohova, Z., Blackstock, J.M., Winzeler, H.E., Smith, D.R., Owens, P.R., Silva, S.H., Curi, N.C. 2024. Heavy metals concentration in soils across the conterminous USA: Spatial prediction, model uncertainty, and influencing factors. Science of the Total Environment. 919. Article 170972. https://doi.org/10.1016/j.scitotenv.2024.170972.
Yost, J.L., Hartemink, A.E. 2024. Some characteristics of sandy plaggen soils. Book Chapter. In: Hartemink, A.E., Huang, J., editors. Sandy Soils. Progress in Soil Science. Switzerland: Springer Nature. https://doi.org/10.1007/978-3-031-50285-9_10.
Schantz, M.C., Smith, D.R., Harmel, R.D., Goodwin, D.J., Tolleson, D.R., Osorio Leyton, J.M., Flynn, K.C., Krecker-Yost, J.L., Thorp, K.R., Arnold, J.G., White, M.J., Adhikari, K., Hajda, C.B. 2024. The LTAR-integrated grazing land common experiment at the Texas Gulf. Journal of Environmental Quality. https://doi.org/10.1002/jeq2.20573.