Optimal design and operating strategies of drip fertigation systems: Toward more uniform irrigation, enhanced fertilization efficiency, and higher crop yield

Drip fertigation system can achieve efficient use of fertilizer and increase crop yields. Therefore, the design and operation methods of the system become particularly important. Six irrigation pressures, two kinds of drip tapes, and three types of filters were evaluated to investigate effects of the system design and operational strategies on irrigation uniformity, soil water content, soil available phosphorus content, and maize yield. Results proved that both irrigation pressures and filters had significant impacts on the Christensen uniformity coefficient (CU) of drip tapes (p < 0.01), and their interaction also exhibited a highly significant influence on the CU (p < 0.01). Higher irrigation pressure increased the average relative flow rate (Qi) of drip tapes; however, the Qi and CU decreased as the drip tape installation length increased, with the values of labyrinth-side emitter drip tapes (LED) declined more significant. The middle section of the drip tape exhibited the highest soil water content and available phosphorus content, where maize yield also reached its peak. The LED required lower irrigation pressure and achieved higher maize yield compared with the arc-shaped emitter drip tapes (AED). The average maize yield ranged from 15395.1 kg/ha to 16654.4 kg/ha at fertigation treatments, falling within a high-yield range. The CU for the LED was greater than 96.04% while the CU for the AED was greater than 91.38% at the optimal operating condition. The optimal configuration for drip fertigation systems was the LED with an irrigation pressure of 0.06 MPa and a 75 μm pore size disc filter (DF75) based on yield performance. However, when the drip tape length exceeded 48 m, the optimal configuration shifted to the AED with the irrigation pressure of 0.09 MPa and the DF75. Appropriate system design and operational strategies in drip fertigation systems play a crucial role in improving maize yield.