Research Project: Managing Agricultural Systems to Improve Agronomic Productivity, Soil, and Water Quality

Location: National Soil Erosion Research Laboratory

2023 Annual Report

Objectives
Objective 1: Develop strategies to mitigate landscape scale attributes for improved soil and water quality and production efficiency. Sub-objective 1.1 Explore surface and subsurface hydrologic processes affecting soil quality and vulnerability on tile-drained landscape. Sub-objective 1.2 Evaluate sources and flow pathways of water and nutrients in tile-drained landscapes. Objective 2: Improve nutrient management efficiency to minimize water quality degradation and maximize agricultural production. Sub-objective 2.1 Assess the influence of combined conservation practices on soil organic matter transformations, nutrient cycling, and crop yield. Sub-objective 2.2 Evaluate soil P drawdown rates, plant phosphorus uptake, and potential changes in corn and soybean yield with elimination of phosphorus fertilizer to long-term fertility research plots. Sub-objective 2.3 Determine the critical phosphorus concentration for corn and soybean cultivars common to the Midwest using the Genetics X Environment X Management (GxExM) approach. Sub-objective 2.4 Evaluate quantity/intensity relationships and the kinetics of phosphorus release in diverse soils in working towards the long-term goal of improving soil fertility recommendations. Objective 3: Develop and refine decision support tools. Sub-objective 3.1 Develop software and database architectures to support collecting and managing observed natural resource data. Sub-objective 3.2 Develop decision support tools to explore and integrate observed field and small watershed data with spatial models. Sub-objective 3.3 Test and improve tools for assessment of climate change impacts on model predictions of soil erosion and chemical losses. Objective 4: Operate and maintain the Eastern Corn Belt LTAR network site in partnership with the Soil Drainage Research Unit, Columbus, OH and the National Center for Water Quality Research, Heidelberg University, Tiffin, OH using technologies and practices agreed upon by the LTAR leadership. Contribute to the LTAR working groups and common experiments as resources allow. Submit relevant data with appropriate metadata to the LTAR Information Ecosystem. Sub-objective 4.1 Develop water, nitrogen, and phosphorus budgets for agricultural fields under prevailing management practices in the Eastern Corn Belt. Subobjective 4.2. Evaluate relationships between soil and water quality, and greenhouse gas emissions under different cropping and management scenarios in the Eastern Corn Belt.

Approach
Objective 1: Both laboratory and field studies will be used to gain a better understanding of the hydrologic processes that control erosion at various locations in the landscape and assess sources and flow pathways of nutrients and water to streams. This will involve assessing the effect of subsurface tile drains on in-stream variability of nutrient concentration and isotopic signatures. Indoor rainfall simulation tools and a stream survey will be utilized to accomplish the listed objective. Objective 2: Regarding soil quality and phosphorus fertilizer recommendations, laboratory and field experiments will be used. Current long-term field experiments where various crop rotations and best management practices have been implemented will provide soils for detailed laboratory analysis to assess the impact of the given practices on soil quality. For phosphorus fertilizer recommendations, the approach is to construct a controlled indoor growth facility and evaluate phosphorus uptake by various crop cultivars, followed by a detailed experiment on quantifying the ability of soil to supply dissolved phosphorus to solutions using long term incubations and various types of extraction methods. Objective 3: Computer programs will be developed for automation of uploading environmental data into the proper format for use by several models, as well as convert to specified data formats, and help interpret validation data from model simulations. This includes incorporation of various future climate scenarios into different models. Objective 4: Discharge, water quality data, and producer surveys will be used to develop water and nutrient budgets for agricultural fields in the Eastern Corn Belt region. This research will link soil quality parameters and soil processes to water quality and gas flux data collected from monitored field sites.

Progress Report
This is the final report for this project and covers research over the past five years. In Sub-objective 1.2, longitudinal stream surveys were completed seasonally in a 9 km section of the Matson ditch in Dekalb County, Indiana. During each stream survey, ditch water samples and ditch sediment were collected every 100 m. All flowing tile drains (n=127) were also sampled during each survey. Water samples were analyzed for water quality (NH4-N, NO3-N, DRP, TKN, TP, electrical conductivity, pH, stable oxygen isotopes), while sediment samples were analyzed for extractable nutrients (water extractable P, Mehlich-3 P, TP), particle size, and stable carbon and nitrogen isotopes. Data from the stream surveys were coupled with landscape information to examine the effect of subsurface tile drains and ditch sediment nutrient concentration on in-stream nutrient dynamics. Data analysis suggests that areas where the ditch intersects closed depressions can be hotspots for nutrient transformation and/or loss. Data from this study are also being used to examine sediment sources throughout the watershed using the carbon and nitrogen isotopes as potential tracers. A laboratory rainfall simulation study was completed using 10 undisturbed soil lysimeters (900 cm3) collected from a long-term agricultural field site in Dekalb County, Indiana. Solute (bromide, chloride) and dye tracers were applied to the lysimeters during eight rainfall simulations to quantify the impact of initial (antecedent soil moisture) and boundary (edge-flow effects) on water and nutrient transport through the shallow vadose zone. Results showed that when the edges of the lysimeters were sealed with petroleum jelly there was significantly less un-natural edge-flow through the lysimeters. Findings also indicated that drier conditions were more conductive to preferential flow through the soil profile compared to wet conditions. Research results have been used to design subsequent experiments examining the effect of climate (rainfall intensity), soil (antecedent moisture), and agricultural practices (tillage) on preferential flow. Findings also have direct implications for agricultural management practice implementation and improvement of computer simulation models. Sub-objective 2.1 involved a multi-location study that investigated the field-scale impact of long-term implementation of combined conservation practices, including cover crops, gypsum, and tillage, on corn and soybean yields and soil health. In addition to the impact of the implementation of single practices, this research allowed us to investigate the interactions between conservation practices implemented in the fields. During the five years, corn and soybean yield was not affected by the implementation of the conservation practices, regardless of the type or combination of practices or site. Implementing conservation practices, gypsum, cover crops, and no-tillage increased soil organic matter (SOM), a critical soil health indicator for cash crops in the U.S. Midwest. The increase of SOM positively impacts nutrient cycling and soil health indicators in the US Midwest. Research will continue in this study to assess the changes in soil properties that might affect soil productivity, including plant nutrients and water quality. Research in Sub-objective 2.2 was implemented to investigate, at the field scale, the long-term impact of phosphorus (P) fertilizer cessation on soil P status and corn and soybean yield at two distinct locations in Indiana. The selected research sites had more than sufficient P soil levels (per standard recommendations) to sustain corn and soybean production. During the 5-year study, corn and soybean yields were unaffected by P fertilizer cessation, indicating that P fertilization might not be needed for soils or fields with sufficient soil P levels. However, these observations cannot be generalized for all situations; more research is needed to assess the long-term corn and soybean yields and the soil P status to determine whether soil P status changes and how it might affect soil fertility. From Sub-objective 2.3, a new and innovative indoor growth room was designed and constructed for conducting crop nutrient uptake studies. This facility allows for complete control of temperature, moisture, photoperiod, and nutrient concentration. It utilizes a sand-culture hydroponics system that prevents nutrient sorption and desorption, thereby allowing total control of the root nutrient environment, which is impossible with soil. The system is semi-automated with nutrient injection, and the light quality is equal to the sun. It produces plants that are chemically and physically identical to field-grown. The technology was used to conduct phosphorus (P) uptake studies on corn and soybean. This led to the discovery of luxury consumption of P by corn, which was previously un-detected due to traditional experiments being conducted in soil. That study also illustrated how excess P uptake by corn can inhibit yield through reduced translocation of copper and zinc from roots to grain, preventing protein development. Similar results were obtained for soybean. Results from the corn study also provide a target for future nutrient recommendation tools by determining that maximum grain yield occurs with uptake of 580 mg P. Related, on Sub-objective 2.4, several benchmark soils were collected from around the United States, including USDA-ARS research watersheds. Soils were characterized for a multitude of properties related to P sorption and retention. Soils were then used in a P rate x pH x soil type incubation experiment. Several extractions are being conducted on the nearly 500 sample group. Data is yet to be analyzed for developing the relationships and potentially a multi-regression model. This model will be used to inform the quantity/intensity P balance within a future nutrient uptake model. For Sub-objectives 3.1 and 3.2, cameras were installed at multiple field sites in the conservation effects assessment project (CEAP) watershed in Northeast Indiana. Images are retrieved at 10 minute10-minute intervals and stored on servers at NSERL. Online access is provided to view recent events, such as high flow events and field flooding. The image data provide additional information to associate field events with sample analysis results. Ongoing field instrumentation updates have been supported through database configuration changes on the server and data access protocol changes on the data loggers and cell modems. Work has also continued in using the Aquarius Informatics database system to catalog and quality check all data for the NSERL field research sites in Northeast Indiana. Scripts were developed in Python to query the Aquarius data elements and extract data. Work with NRCS on the Water Erosion Prediction Project (WEPP) hillslope model web service and web based user interface has incorporated risk statistics related to soil erosion estimates to allow conservation planners to evaluate land management scenarios under varying climate conditions. This interface is available as a web application with simulations run on servers hosted at Colorado State University. The Conservation Resources Land Management Operations (CRLMOD) database of cropping systems parameterized by NRCS and ARS for use with WEPP can be accessed from the user interface. Regarding Sub-objective 3.3, the WEPP (Water Erosion Prediction Project) model team updated the national climate database for the United States, using a consistent 40 years of record (1974-2013). The updated erosivity maps and data were published in an international journal in 2022. Cooperative projects between the NSERL and the NSL (National Sedimentation Laboratory) were conducted to examine WEPP and RUSLE2 erosion model simulations for locations in the state of Iowa and Illinois, as well as effects of climate inputs to the two models obtained from the same stations for the same periods of record. A modified version of WEPP was developed and used to investigate the effects of an atmospheric carbon dioxide (CO2) concentration of 550 ppm (parts per million) projected for the mid-21st century on live biomass and crop yields. Preliminary model results indicated that under irrigated conditions, increases in CO2 level and temperatures may decrease live biomass for corn, soybeans, and winter wheat, but result in a slight increase in crop yields for soybeans and winter wheat, and a decrease in corn yields. Under non-irrigated conditions, model results suggested decreases in live biomass for corn and winter wheat and a slight increase for soybeans. Crop yields under non-irrigated conditions showed increasing trends for all of the studied crops. For Sub-objective 4.1, data on nutrient inputs (fertilizer/manure application rate, atmospheric deposition, irrigation) and outputs (crop removal, runoff losses, leaching losses) were collected from 48 field sites in the Eastern Corn Belt (ECB). These data were used to create nutrient budgets and determine how agricultural practices influenced nutrient budgets. Results showed that both water and nutrient management practices are required to achieve downstream water quality improvements within the ECB. Data from the select ECB field sites were combined with P budgets from across North America through the LTAR and CEAP networks to evaluate the magnitude and uncertainty in nutrient budget calculations. The resulting database (P-FLUX) includes P budgets for 61 cropping systems across North America. Results showed that uncertainty in P budgets are quite large, such that it is not certain whether budgets are increasing, decreasing, or not changing. As a result of this research a set of recommendations was made for the LTAR and other networks for decreasing uncertainty in nutrient budget calculations.

Accomplishments
1. The uncertainty of phosphorus budgets on cropland is often too large to assess phosphorus management. Phosphorus (P) is a critical nutrient for crop growth, but once lost from agricultural fields it can result in eutrophication and harmful algal blooms in downstream water bodies. Improving P use efficiency and developing conservation practices to mitigate environmental impacts of agricultural P inputs are therefore critical for the sustainable intensification of agriculture. Led by ARS researchers in West Lafayette, Indiana, 47 scientists from 15 LTAR network locations and 9 partner organizations in the United States and Canada synthesized data on P inputs (fertilizer/manure application rate, irrigation water, and atmospheric deposition) and outputs (crop removal, surface runoff, and leachate) from agricultural systems. The publicly available dataset produced from this work, the P-FLUX database, includes P budgets and budget uncertainty calculations for 61 diverse cropping systems across long-term research sites in 22 U.S. states and two Canadian provinces. Research results showed that in many cases (39%), the uncertainties in manure or fertilizer applications and crop removal were too large to determine whether P was increasing, decreasing, or not changing. Recommendations were developed to decrease these uncertainties, including measuring the application rate and the P concentration of manures and measuring both crop yield and the P content of the harvested material. Measuring other P fluxes may be important to assess the full impacts of management practices, while measuring the P contained in soil is useful to validate the P budget. The data and recommendations developed through this work can be implemented to facilitate improved quantification of P cycling/loss and be used to address complex local-, regional-, and national-scale P management challenges. The dataset can also serve as framework for collecting similar data from additional production systems for further comparison or be extended to include other data of interest such as nitrogen and carbon fluxes.

Review Publications
Pignotti, G., Crawford, M., Han, E., Williams, M.R., Chaubey, I. 2023. SMAP soil moisture data assimilation on water quality and crop yield predictions in watershed modeling. Journal of Hydrology. 617(C). Article: 129122. https://doi.org/10.1016/j.jhydrol.2023.129122.
Bose, C., Alves, I., Singh, P., Palade, P.T., Carvalho, E., Borsheim, E., Jun, S., Cheema, A., Boerma, M., Awasthi, S., Singh, S.P. 2020. Sulforaphane prevents age-associated cardiac and muscular dysfunction through Nrf2 signaling. Aging Cell. 19:e13261. https://doi.org/10.1111/acel.13261.
Islam, K.R., Dick, W.A., Watts, D.B., Gonzalez, J.M., Fausey, N.R., Flanagan, D.C., Reeder, R.C., Vantoai, T.T., Batte, M.T. 2022. Gypsum, crop rotation, and cover crop impacts on soil organic carbon and biological dynamics in rainfed transitional no-till corn-soybean systems. PLOS ONE. 17(9). Article e0275198. https://doi.org/10.1371/journal.pone.0275198.
Feyereisen, G.W., Ghane, E., Schumacher, T.W., Dalzell, B.J., Williams, M.R. 2023. Can woodchip bioreactors be used at a catchment scale? Nitrate performance and sediment considerations. Journal of the ASABE. 66(2):367-379. https://doi.org/10.13031/ja.15496.
Penn, C.J., Camberato, J., Wiethorn, M. 2022. How much phosphorus uptake is required for achieving maximum maize grain yield? Part 1: Luxury consumption and implications for yield. Agronomy Journal. 13(1).Article:95. https://doi.org/10.3390/agronomy13010095.
Penn, C.J., Camberato, J., Wiethorn, M. 2023. How much phosphorus uptake is required for achieving maximum maize grain yield? Part 2: Impact of phosphorus uptake on grain quality and partitioning of nutrients. Agronomy Journal. 13(1). Article: 258. https://doi.org/10.3390/agronomy13010258.
Williams, M.R., Livingston, S.J., Duriancik, L.F., Flanagan, D.C., Frankenberger, J.R., Gillespie, R.B., Gonzalez, J.M., Huang, C., Penn, C.J., Smith, D.R., Renschler, C.S. 2023. Twenty years of conservation effects assessment in the St. Joseph River watershed, Indiana. Journal of Soil and Water Conservation. 78(1):12A-19A. https://doi.org/10.2489/jswc.2023.1204A.
Williams, M.R., Penn, C.J., King, K.W., Mcafee, S.J. 2023. Surface-to-tile drain connectivity and phosphorus transport: Effect of antecedent conditions. Hydrological Processes. 37(3). Article e14831. https://doi.org/10.1002/hyp.14831.
Watts, D.B., Runion, G.B., Dick, W., Gonzalez, J.M., Islam, K., Flanagan, D.C., Fausey, N.R., Vantoai, T.T., Batte, M., Reeder, R., Kost, D., Chen, L., Jacinthe, P. 2023. Influence of gypsum and cover crop on greenhouse gas emissions in soybean cropping systems. Journal of Soil and Water Conservation. 78(2):154-162. https://doi.org/10.2489/jswc.2023.00042.