Year Established: 2020 Start Date: 2020-03-01 End Date: 2021-02-28
Total Federal Funds: $35,638 Total Non-Federal Funds: $71,288
Principal Investigators: Dr. Gubir Singh
Abstract: The Lower Mississippi River Valley Alluvial Aquifer (MRVAA) is the major source of groundwater for irrigated crop production in the Mississippi Delta. The decline in groundwater levels in MRVAA necessitates the use of better agronomic practices and irrigation systems for saving water and increasing water use efficiency and nutrient use efficiency along with improving runoff and subsurface water quality. The overall goal of this project is to evaluate the effects of irrigation systems on crop water and nutrient use efficiencies and net returns. Specific objectives include: to determine the effects of irrigation methods and row spacing on corn and soybean agronomic characteristics, yield, irrigation water use, water use efficiency, nutrient use efficiency, and economic returns; to train a graduate student in irrigation water management; and to disseminate results to farmers and stakeholders and submit a final report at the conclusion of this project highlighting how above objectives were addressed. The field trials will be established at the Delta Research and Extension Center (DREC) in Stoneville, MS using a randomized complete block design including three irrigation methods (furrow irrigation, sprinkler irrigation, and non-irrigated) and three-row spacings with three replications. Three-row spacings included in this study will be single row planting on raised beds spaced 40-inch, twin-row planting on raised beds spaced 40-inch, and single row planting on raised beds spaced 30-inch. Row spacings will be further split into four soil fertility rates including no fertilizer applied, low, optimum, and high rates of nitrogen in corn and phosphorus in soybean. Continuous corn and soybean will be planted at the recommended seeding rates. Data on plant population, yield and yield components, will be determined for each treatment. Irrigation scheduling will be based on soil moisture monitoring using Irrometer Watermark 200SS soil water potential sensors. Irrigation water use efficiency will be calculated as ratio of crop yield and irrigation water applied. Nitrogen use or phosphorus use efficiency will be calculated based on difference between treatment yield and control yield divided by the rate of nitrogen or phosphorus applied. The results from this study will help producers to select appropriate irrigation methods, row spacing, and fertility rates for increasing corn and soybean yield, net returns and irrigation water and nutrient efficiency under both irrigated and dryland conditions. Results from this study will be disseminated through appropriate media and will be published as peer-review journal article.