Location: Wind Erosion and Water Conservation Research
2025 Annual Report
Objectives
Objective 1: Determine changes in the factors associated with soil health across agroecosystems that are transitioning to dryland agriculture. Our aim is to provide new information on changes of soil organic matter that result in water conservation leading to better soil health-based management decisions.
Sub-objective 1A: Validate a method and categorize soil health across a range of management strategies by simultaneous measurements of key enzyme activities affecting soil biochemistry.
Sub-objective 1B: Examine effects of diverse management practices on microbial soil health and functions related to soil biogeochemical cycling and organic matter dynamics.
Sub-objective 1C: Define and measure soil degradation in various agroecosystems resulting from vegetation change and disturbance and how those factors affect soil crusting, surface erodibility, precipitation capture efficiency, and microbial transport on the fugitive dust.
Objective 2: Assess effects of climatic factors on water limited biotic and abiotic agroecosystem characteristics and processes affecting crop, water, and soil health management.
Sub-objective 2A: Use crop models to evaluate irrigation strategies that maximize water use efficiency and profits in US Southern High Plains cotton production.
Sub-objective 2B: Test whether nighttime CO2 enrichment or high frequency, short-term pulses of CO2 affect plant growth, leaf area or crop water use.
Sub-objective 2C: Define and inspect the theoretical dryland crop production limits achieved by soil management.
Sub-objective 2D: Model conservation agriculture (CA) effects on US Southern High Plains dryland cotton production.
Objective 3: Fundamental investigations of the quality and quantity of various sources of water for agricultural production in the Southern High Plains including groundwater, surface water, and rainwater.
Sub-objective 3A: Develop a method for assessing the value of rainfall, groundwater, and surface water for agricultural uses based upon water chemistry.
Sub-objective 3B: Assess the effects of salty irrigation water on soil surface crusting, erodibility, and soluble dust emissions.
Approach
The challenges that confront Southern High Plains (SHP) agricultural producers are associated with the rapid decline of the Ogallala Aquifer (OA) water table and intermittent rainfall that often is less than the amount required to sustain crop production. The water table’s decline combined with the region’s semi-arid climate is driving a transition from partially irrigated to almost entirely dryland agricultural production. In both marginally irrigated and dryland systems crop management will shift towards optimizing the remaining irrigation resources and adopting innovative crop and soil management approaches. The problems confronting SHP producers during this transition will require solutions that are specific to semi-arid agriculture, minimize risk, and support economic and environmental sustainability. In addition to identifying solutions appropriate for current climate conditions, management decisions will also depend on new knowledge of soil and crop interactions in an evolving CO2 environment. Thus, our project addresses climate factors associated with current highly variable SHP precipitation patterns and rising CO2 levels. Our research will quantify and provide a better understanding of the impacts of soil degradation, climate uncertainty, and changing water availability and quality in semi-arid agriculture. Specifically, we will: 1) develop and validate methods for soil health metrics and use them to evaluate management practices that promote water conservation; 2) account for climate variability when evaluating management practices that affect crop yield, water use and soil health; and 3) develop a method for evaluating water quality of the various sources of water used for production and increase understanding of soil salinity effects on surface crusting, erodibility, and hygroscopic dust emissions emanating from such surfaces. Our results will provide the knowledge needed to sustain agricultural production during the transition to dryland systems in the SHP and in other semi-arid production regions.
Progress Report
This report will cover the third year of the Lubbock, Texas, project addressing questions that stakeholders asked regarding cover crops, crop rotations, and conservation tillage practices to mitigate erosion, improve soil water conservation, and sustain soil health under the challenge of a transition from deficit-irrigation to dryland in the Southern Texas High Plains (STHP). The STHP is crucial to maintain a robust economy in the U.S. as this region leads cotton production and ranks second in sorghum in the nation. With the recognition that problems in agriculture are general, but solutions are site-specific we conduct most of our research directly on producers’ fields. Our year-to-year field experiments provide short-term strategies to maximize profitability, and long-term schemes involve specific cropping system simulation models to explore weather, soil properties, elevation, and crop yield data obtained from satellite imagery. Further, we use machine learning techniques that incorporate specific decision-making algorithms to provide a large-scale assessment of the research questions that are applicable to other semiarid regions.
For Objective 1, we are identifying management decisions associated with improved soil health and mitigation of wind erosion to meet sustainable crop productivity. Healthy soil is crucial to accomplish this goal as it is associated with delivery of nutrients for crops, water conservation from precipitation and processes that lead to organic matter stabilization. For Sub-objective 1A, a scientist from our location is coordinating a national soil health assessment project with 22 ARS scientists from 15 ARS locations across the U.S. Our first goal was to quantify the effects of the weather, soil properties, and conservation practices on the soil microbial communities that are linked to functions associated with crop productivity. Results from using fatty acids extracted from soil microbial communities support the adoption of reduced tillage operations, cover crops, and application of manure, which together show greater sensitivity of fungi than of bacteria to these management practices across different soils. Our team will continue to provide understanding of the interactions of the soil microbial communities with management practices at a national scale to identify the environments that are more challenging to sustain crop productivity. For Sub-objective 1B, we sampled soils in 31 producer-sites transitioning from deficit-irrigation to dryland cropping systems across the STHP. Our soil health assessment on 18 of these sites showed improvements in many of our soil health metrics within the first two years of adopting no-tillage and winter cover crops under both center-pivot irrigation and dryland no-tilled systems (i.e., bacterial, and saprophytic and arbuscular mycorrhizal fungal markers, enzyme activities of nutrient cycling, and various soil organic matter pools). Further, due to the interest of stakeholders in using compost and/or manure, an ARS scientist will assist a producer interested in implementing different combinations of organic amendments, including manure, bio-stimulants, compost and bio-chars. This collaborative effort will establish a soil health assessment framework linking different soil health indicators with functions related to soil water for semi-arid cropping systems. For Sub-objective 1C, we identified locations to collect soil monoliths, i.e., undisturbed vertical sections of a soil profile, that will be used to quantify soil degradation due to changes in vegetation. In our evaluation we will use a rainfall simulator along with a wind tunnel floor section to accommodate the monoliths.
Within Objective 2, Sub-objective 2C we define a theoretical dryland production limit achieved by soil management practices. This evaluation provides a relative rank of a crop yield per water used. The objective is to maximize evapotranspiration (ET = E + T) by maximizing crop transpiration (T) and by minimizing soil water evaporation (E). In dryland crops the only source of water is from rain and stored water in the soil. Thus, soil management practices are evaluated as to their efficacy in maximizing T and minimizing E. Our goal was to calculate the Crop Water Productivity (CWP) in a dryland cotton system as the ratio of cotton lint yield per unit rainfall and CWP was calculated for 16 counties of the STHP. As first analysis we used long-term historical values of lint yield and of measured annual rainfall at the county level. The CWP values were used to rank counties and their agronomic management practices, such as cover crops, crop rotations, planting and termination dates of the cover crop, planting density, and other factors that increase rain infiltration and soil water storage. Our studies suggest that caliche, i.e., a calcium and magnesium carbonate mixture, plays an important role in storing water. We collected soil samples and measured the hydraulic properties of different soils series, all as a function of soil depth. These properties include the relation between the soil water potential as a function of the volumetric soil water content and the relation between the unsaturated hydraulic conductivity and the volumetric soil water content. There is a direct relation between soil water content and cotton lint yield and thus the need to calculate soil water storage is crucial in our evaluation. These functions vary in space, and we have ordered a sensor that will map the depth and the thickness of the caliche. Our research will be done on producer’s fields where we have installed sensors to measure soil water content and temperature. Further, we have installed weather stations to measure environmental variables. Of importance is the measurement of rainfall and for this purpose we installed tipping bucket and doppler radar sensors. Given the spatial variability of soil properties and of rainfall across the landscape, we capture this variability using simulation models that keep track of the inputs (rainfall) and outputs (E, T, runoff, and drainage below the root zone) for different soil properties. ARS scientists in Lubbock, Texas, collaborated with scientists from Texas A&M AgriLife to put together a mathematical model of the growth-stage of sorghum based on different deficit-irrigation scenarios. Simulation results showed that using growth-stage-based irrigation management during normal year, growers could save up to 12% of irrigation water with only about a 1% loss in sorghum yield. These results need to be verified and compared to measured values; however, the STHP has experienced a 4-year drought with no crops. Nevertheless, simulation models are a valuable tool that provide relative values of crop yield in lieu of no measurable cotton or sorghum yield. An additional component of this Sub-objective is the update of the ENergy and WATer BALance (ENWATBAL) simulation model from the Visual Basic language to Python. This will allow us to expedite the many simulations we need to execute to perform a sensitivity analysis on the many combinations of weather, soil properties, agronomic inputs, depth and thickness of the caliche layer.
For Objective 3, Sub-objective 3A, we made considerable progress sampling groundwater, surface water, and rainwater in the High Plains and in the Rolling Plains of Texas. Surface water samples were collected from the Colorado River watershed from the Texas Highway 350 crossing in Scurry County to just above E.V. Spence Reservoir in Coke County in September, 2024. Most locations were dry due to ongoing drought. Samples were collected in June, 2025 and recent rains provided running water in all locations. A total of 12 rainwater samples have been collected through June 12, 2025 from each rainfall event. Half of those events were from May 27 through June 12, hopefully marking the end of a drought. Over the past few years, we have been working with ranchers to investigate the influence of seasonal pumping of the Ogallala Aquifer on the flow and water chemistry of spring-fed streams in the Rolling Plains of Texas. The STHPs is favorably situated above a significant portion of the Ogallala Aquifer, which has provided groundwater for a highly productive irrigated agricultural system since 1910. The extraction of groundwater, coupled with the lack of any significant recharge, has gradually reduced the remaining volume of stored water in the Ogallala. Eventually, many farms on the high plains will be forced to transition from irrigated to dryland agriculture. This shift to dryland agriculture will result in a significant decline in crop production on the STHP. The depletion of the Ogallala Aquifer will also have a negative impact on the number one agricultural product in the state of Texas – beef cattle. In the Rolling Plains to the east of the STHP, there are numerous cattle ranches that benefit from spring-fed streams discharging from the Ogallala Aquifer. These streams provide natural watering places for cattle. Irrigation has altered hydrological conditions, which has reduced the flow of spring-fed streams along the eastern escarpment and thereby has reduced the availability of water for cattle in the Rolling Plains. A paper focused on a comparison of Running Water Draw and the White River of the Texas High Plains will be published for public access. Additional work has been accepted for publication summarizing historical wells and aquifer depletion rates on the Texas High Plains. Within Sub-objective 3B, with the goal to assess the effects of salty irrigation-water on soil surface crusting, erodibility, and soluble dust emissions, we made progress testing several irrigated sites affected by salinity in west Texas. A journal article on humidity effects on the dust emissions and erodibility of saline and sodic soils was published and another on the effects of biochar to ameliorate the effects of salinity is in preparation.
Accomplishments
1. Economic cost of wind erosion. Wind erosion and fugitive dust emissions have an impact on commerce and environmental and human health with the resulting cost to the American economy. An ARS scientist from Lubbock, Texas along with an ARS scientist from Las Cruces, New Mexico, joined with university scientists to quantify those costs for the year 2017, a year in which records were available. The team found that a conservative estimate in excess of 154 billion dollars annually could be attributed to wind erosion and fugitive dust. This dollar amount was only exceeded by the cost of tropical cyclone damage to coastal areas of the United States.
2. National survey of soil health response to crop management across the U.S. Microbes are a crucial component of soil health and affect functions essential to crop productivity such as nutrient cycling, soil organic matter and aggregation, water conservation, and disease control. To understand the microbial response to regional factors and management practices within a national context, a USDA-ARS scientist from Lubbock, Texas, led a multilocation study with 22 ARS scientists from 15 ARS locations across the U.S. At a national scale, the study showed that organic carbon and conservation practices were strong drivers of the soil microbial communities in which reduced tillage, cover cropping, and manure had larger effects on fungal microbial groups than crop diversity. At a regional scale, the results support new efforts focusing on conversion to reduced tillage or adoption of cover cropping to improve soil health under dryland production in the Southern High Plains. This work is important in developing healthy soils and sustaining crop productivity across the nation.
Review Publications
Roper III, W.R., Acosta Martinez, V., Veum, K.S., Burgess, C.J., Moore, J.M., Manter, D.K., Stewart, C.E., Emmett, B.D., Liebig, M.A., Fischel, M.H., Lehman, R.M., Franco Jr, J.G., Johnson, J.M., Weyers, S.L., Mikha, M.M., Trippe, K.M., Maul, J.E., Dungan, R.S., Gollany, H.T., Ducey, T.F., Hale, L.E., Jin, V.L., Cavadini, J., Reardon, C.L. 2025. Unraveling edaphic, environmental, and management drivers of soil microbial communities via ester-linked fatty acid methyl esters using a multilocation agroecosystem study. Geoderma. 453. Article 117158. https://doi.org/10.1016/j.geoderma.2024.117158.
Khatei, G., Rinaldo, T., Van Pelt, R.S., D'Odorico, P., Ravi, S. 2025. On the differential effects of salinity and sodicity on aeolian erosion dynamics and particulate emissions. Earth Surface Processes and Landforms. 50(4). https://doi.org/10.1002/esp.70040.
Goebel, T.S., Mahan, J.R., Payton, P., Young, A.W., Pugh, N.A., Xin, Z., Stout, J.E., Gitz, D.C., Lascano, R.J. 2025. Quantifying temporal distortions of artificial UAV crop canopy temperature measurements. Remote Sensing. 14(2). https://doi.org/10.4236/ars.2025.142006.
Weindorf, D.C., Acosta Martinez, V. 2025. Fundamentals of soil characterization. In: Weindorf, D.C, Chakraborty, S., Li, B. Unlocking the Secrets of Soil. Cambridge, MA: Elsevier. p. 17-61.
Himanshu, S.K., Ale, S., Bell, J., Fan, Y., Samanta, S., Bordovsky, J., Gitz, D.C., Lascano, R.J., Brauer, D.K. 2023. Evaluating growth-stage-based variable deficit irrigation strategies for improving yield and irrigation water use efficiency of grain sorghum. Irrigation Science. 280. https://doi.org/10.1016/j.agwat.2023.108222.
Feng, I., Tong, D.Q., Gill, T.E., Van Pelt, R.S., Webb, N.P. 2025. The economic costs of wind erosion in the United States. Nature Sustainability. 8:307-314. https://doi.org/10.3390/agriengineering6040254.
Polyakov, V.O., Baffaut, C., Ferro, V., Van Pelt, R.S. 2023. Advances in soil erosion research: mechanisms, modeling and applications - A special issue in honor of Dr. Mark Nearing. International Soil and Water Conservation Research. 11(4):589-591. https://doi.org/10.1016/j.iswcr.2023.08.006.