1a. Objectives (from AD-416)
(1) Develop methods and techniques for design, operation, and management of irrigation systems in the Mid-South region. (2) Develop and evaluate the benefits and limitations of site-specific management technologies for irrigated agriculture in the Mid-South region. (3) Determine interactions between irrigation and agronomic practices, and identify cultivars/practices to overcome problems encountered in irrigated cotton and soybean production for the Mid-South region. (4) Determine the impacts of irrigation and irrigated crop production on water quality in the Mid-South region.
1b. Approach (from AD-416)
To optimize irrigated crop production and protect soil and water resources in the Mid-South, it is necessary to consider natural soil variability within fields, the range of crops and production systems, and the types of irrigation systems employed. Our interdisciplinary team will address limitations to the overall goal of improving performance, profitability, and sustainability of Mid-South agriculture. We will investigate ways to improve irrigation scheduling and mechanized-irrigation-system management in spatially-variable soils. We will explore use of commercial sensors to provide information regarding crop water status and flood-water depth. Building on our previous research, we will investigate flood tolerance among cotton and soybean cultivars and plant introductions to reduce the risks associated with irrigating in humid climates; and investigate the water quality impacts of irrigated agriculture. We will investigate advantages and limitations to site-specific irrigation. Building on our long-term experience with irrigation scheduling, we will assess the options available for Mid-South irrigators. Site-specific irrigation and rice production system evaluations will include on-farm research with active participation by crop producers and crop advisors. Products of this research will include a sensor system for monitoring rice fields, water-conserving production systems for rice production, and improved flood tolerance for surface-irrigated Mid-South crops.
3. Progress Report
Efforts concentrated on continuing studies described in Project Plan that include objectives from both ARS and University of Missouri scientists. Under ARS leadership: 1. In cooperation with: NRCS, a rice producer in the Conservation Security Program, the University of Arkansas, and a private company developing a similar type of system, wireless sensors were installed in six paddies of two rice fields to alert the producer when water levels in paddies were low and when paddies were full. The system could be set only to alert or to automatically start and stop the diesel power unit. 2. Instrumentation was installed on a center pivot irrigation system equipped for variable rate application to monitor the performance of the system. The system was operated under a wide range of conditions to determine the potential for variable rate irrigation to reduce water and energy use. Additional sensors were obtained to further investigate the system performance. 3. Consulted with agrochemical dealers to determine the most heavily used products in the region; products and their typical times of use will be used to plan a study to investigate the quality of runoff from irrigated fields. Through the Specific Cooperative Agreement with the University of Missouri Delta Center (see also 3622-13610-002-01S, Improving Irrigated Crop Production in Southeast Missouri): 1. Used 152-m pivot to incorporate variability into irrigation management. Soil maps, soil textural field samples, and aerial photos were used to divide the field into specific treatments. Corn was used to establish a baseline for the irrigation scheduling procedure. 2. Studies addressed twin-row production of corn, cotton, and soybean on sand, silt, and clay soils. Related studies addressed skip-row cotton production and various furrow flow rates. 3. Information on commercial automated sensors was added to the Mo. Agricultural Electronic Bulletin Board (AgEBB). Experiment compared three commercial automated sensor systems to traditional irrigation scheduling software. 4. Analyses were done on irrigation energy management and monetary savings from using various cost-reducing strategies and six energy-related computer programs were placed on AgEBB. Five system tests were conducted and arrangements were made to install a datalogger and sensors to measure operating characteristics on an electric, open-discharge well. 5. Initiated final season of small-plot studies employing a wide range of cotton seeding rates on sandy and silt loam soils; three-year results will be used in subsequent large-plot tests. 6. Screened commercial cotton varieties for tolerance to mid-season flooding with both flooded and non-flooded treatments. 7. Evaluated soybean cultivar and PI tolerance to gradual and fast flooding of soil in greenhouse and started follow-up study. 8. Initiated study of sprinkler irrigated rice. Research addresses the following Problem Areas in the NP201 Action Plan: 2.1: Irrigation Scheduling for Water Use Efficiency; 2.4: Site Specific Technologies to Conserve Water, Nutrients, and Energy; 2.5: Cropping and Tillage Strategies to Best Use Limited Water Supplies; and 6: Water Quality Protection Systems.
5. Significant Activities that Support Special Target Populations
Vories, E.D., Hogan, R., Tacker, P., Glover, R., Lancaster, S. 2007. Estimating the cost of delaying irrigation for midsouth cotton on clay soil. Transactions of the ASABE. 50(3):929-937.