Improving corn production by adopting efficient fertigation practices: Experimental and modeling approach

Abstract

Crop and water productivity can be improved by growing crops under drip irrigation coupled with balanced fertigation and adequate irrigation scheduling. A two year study was conducted to investigate corn productivity under different irrigation frequencies (DIF: daily irrigation frequency, 3DIF: 3rd day irrigation frequency and 5DIF: 5th day irrigation frequency) and fertigation rates [100RDF: 100% RDF (recommended dose of fertigation), 75RDF: 75% RDF and 50RDF: 50% RDF]. The results showed that DIF coupled with 100RDF produced the highest PLH:plant height (195.96 cm), DMW:dry matter weight (18.78 t/ha), GY:grain yield (9.98 t/ha), WP:water productivity (1.78 kg/m3) and net profit (US$/ha. 1070). Treatments under drip irrigation saved 48% irrigation water with an average irrigation depth of 556 mm in comparison to 1063 mm under ridge sowing. The SALTMED model simulations showed good performance with root mean square error (RMSE) ranging from 0.007 to 0.012 for soil moisture and 0.305 to 0.376 for soil salinity; coefficient of determination (R2) ranged from 0.802 to 0.864 for soil moisture and 0.828 to 0.875 for soil salinity; and coefficient of residual mass (CRM) ranged from −0.028 to 0.024 for soil moisture and 0.054 to 0.242 for soil salinity. The highest percentage of difference (%D) between observed and simulated values for DMW and GY was 2.56% and 19.65%, respectively. The RMSE, R2 and CRM were found as 0.513, 0.831 and −0.013, respectively for DMW and 0.606, 0.899 and −0.028, respectively for GY. The scenario simulation showed that DMW and GY increased 2.9% and 1.6%, respectively with increase in RDF from 100% RDF to 125% RDF that reduced net profit upto 11.6%. Based on these findings, it is recommended that drip irrigation should be operated on a daily basis coupled with 100RDF for economical corn production.