Demonstration of Integrated Irrigation Management to Improve Water and Nutrient Use Efficiency, Soil Health, and Water Quality in Furrow Irrigated Agriculture

In Louisiana, agricultural acres under irrigation has increased over the years. Irrigation is necessary because of the erratic distribution of rainfall and prolonged dry spells at critical crop growth stages. According to the Farm Service Agency, about 40% of the row crops were under irrigation in 2016. Among the different types of irrigation, furrow irrigation (FI) constitutes significant portion of irrigated agriculture in Louisiana. Although FI with the use of polypipe is very inexpensive compared with other types of irrigation, such as center pivot or linear moving or drip irrigation systems, efficiency is as low as 40%. Based on the soil texture and slope of the field, the efficiency could be little higher or lower. Deep percolation, especially in light textured soils, and edge of field runoff are the major pathways of water loss in addition to surface evaporation. Uneven wetting of the field (excessive water at the beginning of the row and a deficit of water at the end of the row) can cause poor crop yields. In addition to FI’s poor efficiency, irrigating crops based on soil touch and feel or visual observation methods lead to improper timing of irrigation.
Overall, poor irrigation efficiency of FI not only contributes to less than optimum crop yields and increased cost of cultivation, but also lead to loss of nutrients, sediment and soil organic matter, which ultimately lead to the decreased soil fertility. Clearly, there is an opportunity to improve the efficiency of FI through the implementation of existing knowledge.
An integrated irrigation management (IIM) approach was developed to improve FI’s efficiency that can also conserve nutrients and sediment loss. The proposed IIM approach uses surge irrigation, TDR soil moisture sensors, PHAUCET for polypipe hole selection, and consideration of crop growth stage to improve overall water use efficiency.