Nutrient mobility in soil, uptake, quality and yield of Suru sugarcane as influenced by drip-fertigation in medium vertisols

The results of field experiments conducted during 1997–99 using FRBD with 9 treatments and 3 replications, 250:115:115 kg ha⁻¹ N-P₂O₅-K₂O and irrigated at alternate day through drip (water requirement computed on the basis of CPE, pan factor, crop coefficient and area factor) in Vertisols to Suru sugarcane (cv. CO. 86032) indicated that comparatively more N, P and K were available in the soil from water soluble fertilizers. Nitrogen and K moved laterally from point source up to 15 cm and vertically up to 15–25 cm and P moved 5 cm both laterally and vertically and thereafter dwindled. The higher quanta of N, P and K availability were observed in 125% recommended dose of fertilizers. Application of water soluble N, P and K fertilizers (applied in 20 equal weekly splits) significantly yielded more cane yield (153.35 t ha⁻¹) and uptake of N (194.41 kg ha⁻¹), P (73.8 kg ha⁻¹) and K (288 kg ha⁻¹) when compared with straight fertilizers (N through urea in 20 equal weekly splits and P and K as basal). The quality parameters viz. RS (0.38%), NRS (16.23%), N (92.01 mg/100g) and P (37.98 mg/100g) contents in cane juice were found to be significantly more in water soluble fertilizerswhen compared with straight fertilizers. Application of fertilizers through drip resulted in significant increase in cane yield (28%), WUE (114%) and water saving (41%) over surface irrigation method. Further, application of 100% of recommended dose of fertilizers through drip was found to be the best in cane production. The net extra income accrued due to use of water soluble fertilizers was 6.57% higher (Rs. 59190 ha⁻¹) than the straight fertilizers. However, additional benefit accrued due to Rictifield water soluble fertilizer was masked by straight fertilizer owing to the high cost of the former than the latter.