2013 Annual Report
1a.Objectives (from AD-416):
Develop cropping systems, conservation management practices and crop rotations with improved water management and enhanced economic and environmental sustainability.
1b.Approach (from AD-416):
Improved irrigation scheduling and application technologies and water management tools will be developed and delivered to producers to improve water use and crop yield and quality. The research will develop production systems and identify management practices that improve soil quality and increase profitability by incorporating conservation production practices, alternative crops and crop rotations. Profitability of management practices and production systems will be tested with economic analysis. Fundamental principles of successful production systems will be delineated, and examined for impacts on risks, competitiveness and environmental impacts.
Significant progress was made in the implementation and testing of water management tools. The new Mississippi Irrigation Scheduling Tool (MIST) was tested and validated for common corn and soybean production practices and soil types in Mississippi in research and production fields. Watermark soil water sensors were installed at six inch (15 cm) increments to a depth of three feet (0.91 m), and soil water measurements downloaded weekly. Plant growth measurements were taken weekly, and used to develop single crop coefficients as outlined in established procedures. Dual crop coefficients are being explored as a possible method of accounting for variability of alluvial soils. Soil water measurements and plant growth measurements were compared to evapotranspiration calculations made with the Modified Penman-Monteith in the MIST program to adjust crop coefficients to better reflect actual crop water use in the soils and environment of the Delta. Water release curves for typical Mississippi soils were developed and soil moisture sensors calibrated to known water contents. Soils textural analysis is used to adjust recommended irrigation levels based on soil water holding capacity. Note that most soils are silt and loam; no soils that were analyzed were true clay soils. Analyzed soils will have approximately 1.2–2.5 inches of plant available water per foot of soil. Soil cores were taken from production and research fields, and bulk density, soil nutrient and soil hydraulic properties determined. Weather data was downloaded from all weather stations reported by the Delta Research and Extension Center Weather Center and Natural Resources Conservation Service (NRCS) Soil Climate Analysis Network (SCAN) weather systems was analyzed for completeness and accuracy.
The impact of planting date and irrigation on soybean yield was determined. Early planted soybeans yielded higher, but were more susceptible to lack of adequate water. Two primary crop parameters can be used for tracking crop growth: plant height and interception of sunlight. Results show that light interception is more appropriate for tracking crop growth as a single curve can be used for most planting dates. Plant height differs with planting date. The overall magnitude of crop height is most likely cultivar dependent. However, later planting increases the rate of crop growth, altering the initial stage of the crop height growth curve.
The uniform resource locator for the web site server is now open. We have begun writing summaries and educational materials for the water management website. The information can be viewed at: http://www.agwater.msucare.com. The irrigation scheduler has been implemented into the user interface, and the interface is being tested.
Grzebisz, W., Gaj, R., Sassenrath, G.F., Halloran, J.M. 2012. Fertilizer use and wheat yield in Central and Eastern European countries from 1986 to 2005 and its implication for developing sustainable fertilizer management practices. Communications in Soil Science and Plant Analysis. 43:2358-2375.
Parajuli, P.B., Jayakody, P., Sassenrath, G.F., Ouyang, Y., Pote, J.W. 2013. Assessing the impacts of crop-rotation and tillage on crop yields and sediment yield using a modeling approach. Agricultural Water Management. 119:32-42.