Real-Time Sprinkler Irrigation (RTSI) Scheduling for Improving Wheat Crop Water Productivity in Vertisols

An experiment was conducted at ICAR- Central Institute of Agricultural Engineering (CIAE) Bhopal, Madhya Pradesh, India, during the rabi seasons of 2017-18 and 2018-19 with the objectives of to study improved irrigation scheduling for enhancing water productivity of wheat crops in Vertisols. The experiment involved permanent raised bed cultivation in Vertisols and was laid out in Randomized Block Design (RBD) with two planting systems (elevated bed and flatbed) replicated three times. The elevated bed levels were set as 5, 10, 15 and 20 cm. Soil moisture was continuously monitored using a real-time sensor network sprinkler irrigation, during crop growth period. Field data on soil moisture, crop performance, and yield were regularly recorded at different crop growth stages. The results indicated that both conventional sprinkler irrigation and real-time moisture sensor-based sprinkler irrigation led to substantial water savings of 27 and 35%, respectively with corresponding yield increase of 9 and 15% when compared to gravity (flood) irrigation, showing their effectiveness. Soil moisture variability study revealed that average soil moisture levels significantly varied when bed elevation was 10 cm or more, as compared to control (bed with normal field level) in different crop physiological stages. This variation occurred under sprinkler irrigation in Vertisols for recommended irrigation water depth. Under recommended irrigation water application through sprinkler, the wheat crop yield increased for elevation variations up to 10 cm bed elevation and the yield reduced significantly for more than 15 cm bed elevation. For sprinkler irrigation, the developed irrigation water application prescriptions (water depth/irrigation) include 400 mm irrigation depth (ID) for bed of 0 cm elevation, 476 mm ID for bed of 20 cm elevation and 552 mm ID for 30 cm bed elevation to sustain the wheat crop yield under soil moisture variability in Vertisols.