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ARS Home » Midwest Area » West Lafayette, Indiana » National Soil Erosion Research Laboratory » Research » Research Project #435642

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

Location: National Soil Erosion Research Laboratory

2019 Annual Report

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.

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
In the St. Joseph River watershed, a stream reach (~3.5 km) within the Matson Ditch subwatershed has been identified to evaluate the influence of subsurface tile drains on spatial patterns of nutrient concentration and isotopic signatures. The entire length of the study reach has been walked, where the location and diameter of 127 subsurface tile drains has been inventoried. Plans for collecting water samples from the stream and select subsurface tile drains are underway, as we work cooperatively with the County Drainage Board members to access the study reach. The isotope analysis of collected water samples require an intensive multiday laboratory pretreatment. Preliminary laboratory testing of this new sample analysis method is ongoing and has resulted in several key advancements and/or addendums to previously published approaches. Soil boxes or lysimeters for the collection of intact, undisturbed soil cores were used to assess the effect of drainage water management practices on water quantity and quality. A preliminary experiment was conducted to test the procedures for sealing the edges of the lysimeters with petroleum jelly. Three, one-hour rainfall simulations were conducted on the lysimeters. During the first two rainfall simulations, chemical (i.e., bromide and chloride) and water isotope tracers were used to elucidate flow pathways through the soil and determine if water (and the applied tracers) flowed through the bulk soil or along the edge of the lysimeter casing. During the third rainfall simulation Brilliant Blue dye was added to the rainfall to visualize flow pathways during post-rainfall destructive sampling. Results are being summarized in two peer-reviewed journal articles. Cover crops, manure, and gypsum were implemented in fall of 2018 to their respective plots at Davis Purdue Agriculture Center. Also, soil, plant tissue, and grain were collected for the analysis of Mehlich-3 extractable nutrients in soils, C/N in soils, plant tissues, and grain, and protein/oil content in grain samples. Grain samples were sent to ARS scientists in Peoria, Illinois, for protein and oil content; whereas soil and plant samples are being processed in the lab for analysis. The second year of this experiment started in Spring 2019 with the harvest of cover crops and the planting of corn/soybean. To understand the crop's need for phosphorus fertilization, 16 plots were selected at Davis Purdue Agriculture Center. These plots have been in corn/soybean rotation under no-till tillage for at least 5 years. Soil samples were collected in 2018 to determine the background fertility levels. Eight plots had “High” levels of P (~ 75 ppm Mehlich-3), whereas eight plots had “Medium” Levels of P (~ 40 ppm Mehlich-3 P). For each level of P (i.e., High and Medium P), four plots were selected to receive P fertilizer to replace the P amount removed by harvest; whereas the other four plots did not receive any P additions. In May 2019, the 16 plots were planted with corn. Plants will be sampled and yield monitored to help develop an efficient P fertilization recommendation. Completed the construction and testing of an indoor growth chamber/growth room. This room is capable of growing 96 corn plants to full maturity with 100% artificial conditions. Solution nutrient concentrations exposed to plant roots could be controlled through the addition of nutrients to the drip irrigation system. An automated sand-hydroponics nutrient dosing and irrigation system was constructed to allow for precise control, and for flexibility among research treatments. Climate is controlled through a positive ventilation system in which all air entering the room through a large duct fan is first filtered and then distributed throughout the room, with displaced air being forced through a different vent. Temperature and moisture are monitored and maintained at desired levels. Optimum management for both climate and nutrient concentrations were tested and adjusted. Corn plants were successfully grown to full maturity, producing a plant that is identical to field-grown corn. A collection of archived soils was tested with several different methods of extracting water soluble phosphorus, that may be most representative of plant root conditions. Additional samples may need to be collected to have a diversity of soils. Calorimetry experiments are being designed for the possibility of measuring P desorption in real-time through use of an isothermal titration calorimetry. Sensor data from NSERL field sites continues to be uploaded to a central website where users can view the latest weather and soil moisture data. Access to real-time weather data was configured for the local ARS Long Term Agroecosystem Research (LTAR) site to allow data to be uploaded to the National Agricultural Library repository. Work has also progressed in setting up a local area network at the site to allow additional instrumentation. The field site network supports cameras through continuous video streaming. A prototype web user interface was developed based on the open source Grafana time-series analytics software for a very small subset of field site data. This interface will continue to be developed and linked to existing data. Substantial efforts have been undertaken on assessment of climate datasets within the United States that can be used for soil erosion predictions. Development has focused on improving all of the following climate forcings of NSERL tools: observed climate via national weather station data, and simulated (present and future) climate via Global Climate Model (GCM) and Regional Climate Model (RCM) outputs. These improvements are being implemented in the context of vastly improved GCM and RCM capabilities, as well as the modernization of observed weather datasets. The goal of new developments is to assimilate these state-of-the-science GCM outputs to have a reliable benchmark for comparisons. The CLIGEN climate database was updated for the U.S., using a consistent 40 years of record (1974-2013). This update improved simulated weather sequence when temperature falls below freezing. Recent analysis of CLIGEN simulated rainfall events show that they are more vigorous than those from observed weather station data. Efforts are underway to assess additional climate databases used by different prediction models to ensure proper benchmarking when estimated erosion from these models are compared. To facilitate the processing of weather station data, a new software tool called WEPPCLIFF (WEPP CLImate File Formatter) has been developed. It can utilize either breakpoint rain gauge input data or fixed interval weather station data (e.g. 15-min precipitation) to prepare observed climate inputs for erosion prediction. A beta version is currently being tested for providing automated quality checking and gap filling.

1. Rainfall, soil moisture, and conservation practices influence the hydrology of drained closed depressions. Closed depressions or potholes are common landscape features across the U.S. Midwest. Over the past 150 years, artificial drainage systems have been installed in many closed depressions to remove water and facilitate crop production. Using long-term edge-of-field data, ARS researchers in West Lafayette, Indiana, assessed the impact of rainfall characteristics (e.g., amount, intensity), antecedent soil moisture, and conservation practice implementation on water and nutrient transport from a drained closed depression. Findings showed that both surface runoff and subsurface tile flow in these landforms only occurred when rainfall during a storm event exceeded the soil moisture deficit. Installing a blind inlet significantly altered the flow patterns of the depression compared to a traditional tile riser, where the implementation of the conservation practice may increase or decrease the duration of flow and cumulative flow depending upon the extent of subsurface tile drainage within the depression. Research results have significant implications for the design and implementation of conservation practices in closed depressions, as previous drainage installation may influence the effectiveness of blind inlets for improving water quality.

2. Improving and clarifying our understanding of how pH impacts the solubility of soil phosphorus. There has been some controversy regarding the impact of pH on soil phosphorus (P) solubility. Traditionally, growers and scientists understand that max P solubility and plant uptake occurs near pH 7. However, some scientists recently claimed that max P solubility occurs at a much lower pH. Such a difference in management would have a major impact on agronomic production. ARS scientist and university cooperator at West Lafayette, Indiana, studied the case made by the scientists who hold this opposing view, and analyzed in great detail, many studies conducted on the topic over the past seventy years. The results showed that valid exceptions to the rule of thumb of max P solubility at near-neutral pH do occasionally occur due to interacting P sorption mechanisms, and occasionally because of certain techniques used for adjusting pH. Overall, however, the classic view of maximum P solubility at near-neutral pH was found to be true. Maximum solubility means that the plant will have greater access to the P, and therefore produce greater yield. This information is important to both scientists and especially consulting agronomists who make recommendations on optimum pH to countless producers in the U.S. It was critical to produce this contemporary work in order to reduce the spread of mis-information that would have a negative impact on agronomic production.

3. Construction of an indoor growth room for conducting nutrient studies on plants. ARS researchers at West Lafayette, Indiana, designed and constructed an indoor growth room in which plants are grown hydroponically in silica sand under controlled conditions. This allowed precise control of solution nutrient concentrations and changing them at any time through dosing irrigation water, which is impossible when using soils. The silica media was studied separately in the laboratory in order to verify this. Ninety-six corn plant were grown to full maturity under 100% artificial conditions, including light and temperature, producing plants identical to optimum field-grown conditions. This new growth room provides an articulate tool for studying plant-nutrient-environment interactions and nutrient transport processes and will be very helpful to researchers. Until this accomplishment, it was widely held that under artificial conditions, corn could not be grown to full maturity and produce a plant that resembled a field-grown corn plant. University researchers are inquiring and now attempting to create a similar system for their research needs.

Review Publications
Penn, C.J., Camberato, J.J. 2019. A critical review on soil chemical processes that control how soil pH affects phosphorus availability to plants. Agriculture. 9(6):120.
Hanrahan, B.R., King, K.W., Williams, M.R., Duncan, E.W., Pease, L.A., Labarge, G.A. 2019. Nutrient balances influence hydrologic losses of nitrogen and phosphorus across agricultural fields in northwestern Ohio. Nutrient Cycling in Agroecosystems. 113(3):231-245.
Yobi, A., Batushansky, A., Oliver, M.J., Angelovici, R. 2019. Adaptive responses of amino acid metabolism to the combination of desiccation and low nitrogen availability in Sporobolus stapfianus. Planta. 249(5):1535-1549.
Penn, C.J., Rutter, E.B., Arnall, D.B., Camberato, J., Williams, M.R., Watkins, P. 2018. A discussion on Mehlich-3 phosphorus extraction from the perspective of governing chemical reactions and phases: Impact of soil pH. Agriculture. 8(7):106.
Peterson, H., Williams, M.R., Frankenberger, J., King, K.W., McGrath, J., Moody, L., Ribaudo, M., Strock, J. 2019. Reducing the impacts of agricultural nutrients on water quality across a changing landscape. Council for Agricultural Science and Technology Issue Paper. 64:1-60.
Plach, J.M., Macrae, M.M., Williams, M.R., Lee, B.D., King, K.W. 2018. Dominant glacial landforms of the lower Great Lakes region exhibit different soil phosphorus chemistry and potential risk for phosphorus loss. Journal of Great Lakes Research. 44:1057-1067.
Williams, M.R., Livingston, S.J., Heathman, G.C., McAfee, S.J. 2019. Thresholds for runoff generation in a drained closed depression. Hydrological Processes.
Chen, J., Liu, Y., Gitau, M.W., Engel, B.A., Flanagan, D.C., Harbor, J.M. 2019. Evaluation of the effectiveness of green infrastructure on hydrology and water quality in a combined sewer overflow community. Science of the Total Environment. 665:69-79.
Mehan, S., Gitau, M.W., Flanagan, D.C. 2019. Reliable future climate projections for sustainable hydro-meteorological assessments in the Western Lake Erie Basin. Water. 11(3):581.
Srivastava, A., Flanagan, D.C., Frankenberger, J.R., Engel, B. 2019. Updated climate database and impacts on WEPP model predictions. Journal of Soil and Water Conservation. 74(4):334-349.
Zixuan, Q., Shober, A.L., Scheckel, K.G., Penn, C.J., Turner, K.C. 2018. Mechanisms of phosphorus removal by phosphorus sorbing materials. Journal of Environmental Quality. 47:1232-1241.