Optimization of Nitrogen Dose through Fertigation in Cauliflower under Drip Irrigation

Proper management of nitrogenous fertilizers is of paramount importance for economical crop production and sustainable soil-water-atmosphere ecosystem. The present study was conducted to examine the effect of different nitrogen fertigation levels on cauliflower crop through drip irrigation. The nitrogen fertilizer (urea) was applied in 35 equal doses with irrigation water applied at alternate day through drip irrigation system. Soil moisture in the soil profile of different treatments was recorded at fortnight interval. The observed moisture content tended to decrease with increase in radial distance from the drip lateral at all soil depths. The soil moisture tended to decrease with increase in soil depth at all radial distances, throughout the soil profile, during whole crop period, in all the treatments. The cauliflower yield with N-fertigation of 90 kg ha-1 (75% of Recommended dose of N), 120 kg ha-1 (100% RDN) and 150 kg ha-1 (125% RDN) was found to be 221 q ha-1, 231 q ha-1 and 234 q ha-1 respectively. The water use efficiency (WUE) was calculated to be 80.7 kg m-3, 84.2 kg m-3 and 85.4 kg m-3 under 75% RDN, 100% RDN and 125 % RDN respectively. The nitrogen use efficiency (NUE) was found to be 245.6 kg kg-1, 192.2 kg kg-1 and 156 kg kg-1 under 75% RDN, 100% RDN and 125% RDN respectively. The increased N-fertigation level did not improve the cauliflower yield and WUE much but reduced the NUE to a great extent.