Optimizing irrigation management: evaluating silage maize water requirements using soil moisture monitoring

Proper irrigation planning conserves water, reduces deep percolation losses, and improves water efficiency. This study evaluated the water needs of silage maize (ZP 606) using a method for monitoring soil moisture in Pishva, Varamin (in 2019) with a split-strip plot design and three replications. The primary factor included three irrigation levels: 120%, 100%, and 80% of crop water requirement (I2, I1, and I3), while the secondary factor comprised pulse (P) and continuous (C) irrigation management. Actual evapotranspiration (ETa) was measured using the soil water balance method. It was 364 mm (pulse) and 341 mm (continuous) under full irrigation, 348 mm and 336 mm under deficit irrigation, and 383 mm and 352 mm under over-irrigation. FAO-56 estimated ETc at 400 mm, about 13.5% higher than the observed ETa under full irrigation. When compared to continuous irrigation under over-irrigation conditions, pulse irrigation decreased deep percolation by around 30%. According to the results, pulse irrigation reduces deep percolation losses and improves water use efficiency. Furthermore, local adjustments are necessary for FAO-56 estimations to produce more realistic forecasts.