Location: Sustainable Water Management Research
Project Number: 6066-13000-006-017-S
Project Type: Non-Assistance Cooperative Agreement
Start Date: Sep 20, 2021
End Date: Sep 19, 2026
Objective:
1. Compare agronomic and economic returns of controlled tile drainage with and without subsurface irrigation to the standard non-drained raised bed practice with and without furrow irrigation.
2. Conduct this research on both a very poorly drained and somewhat poorly drained soil to evaluate impact of soil texture/soybean varieties on the effectiveness of these management systems.
3. Quantify water consumption of the different systems for determining irrigation water use efficiency.
Approach:
We hypothesize that the use of subsurface controlled tile drainage with irrigation system can improve crop productivity on very poorly drained soils and irrigation application efficiency.
We will compare the standard land preparation practice of raised beds/furrow irrigation to the controlled tile drainage with irrigation practice. All experimental treatments would be on raised beds with the following treatments: a) non-drained and non-irrigated; b) non-drained and furrow irrigated; c) controlled drained and furrow irrigated; d) controlled drained with subsurface irrigation. These side-by-side treatments in the long-term would allow us to determine the economic value of these systems and determine if controlled drainage with irrigation could be a potential option for Mississippi soybean producers. To achieve Objective 2, the experiment will be conducted at two sites and with different soybean varieties. One site will be a Sharkey clay soil texture and the other loam. Different soybean varieties based on soybean maturity groups will be grown providing for a comparison of multiple soybean varieties with different water requirements and stress tolerance. Watermark Model 200SS soil water potential sensors will be installed at 6, 12, and 24-inch soil depths within one replication. A season long irrigation threshold of -85 kPa will be used to schedule irrigation to soybean. Irrigation will be applied when the weighted average of the soil water potential in the 0 to 24 inch rooting depth will reach the threshold. Irrigation will be terminated at the R6.5 growth stage. Water flow meters will be installed on each irrigation system for determining the amount of irrigation water consumed for each system. Irrigation water use efficiency will be calculated for each treatment as ratio of soybean yield with irrigation water applied.
