Response of spring-planted sugarcane (Saccharum officinarum) to phosphorus and sulphur application

An experiment was conducted during the spring season of 2003-04 and 2004-05 on sandy loam soil at Pusa, Bihar to study the effect of four levels each of phosphorus (0, 17.5, 35.0 and 52.5 kg/ha) and sulphur (0, 40, 80 and 120 kg/ha) on growth and yield of sugarcane (Saccharum officinarum L.). Application of 35.0 kg P/ha to sugarcane recorded significantly higher mean growth (tillers, 175,000lha; cane length, 221.0 cm; leaf area index, 4.04), yield attributes (millable canes, 131,1 OO/ha; single-cane weight, 570 g; cane diameter, 2.02 cm) and cane yield (73.54 t/ha) over no P. The mean increase in cane yield with application of 52.5,35.0 and 17.5 kg P/ha over the control was 20.77, 18.83 and 9.97 respectively. Application of 35.0 kg Plha registered an increase of 4.4 in su¬crose content in juice, 31.8 in P uptake and 22.1 in S uptake over the control. The use efficiency of P decreased with corresponding increase in its level. However, S-use efficiency was maximum at higher level of P ap¬plication. Apparent P recovery was the highest at 35.0 kg P/ha (8.07 and 8.68), whereas apparent S recovery progressively increased with increase in P levels from 0 to 52.5 kg/ha. The response of sulphur was also pro¬nounced at 80 kg/ha as evident from significant increase in mean cane length (219 cm), leaf area index (4.02), number of millable canes (131 ,OOO/ha), single cane weight (566.0 g), cane yield (73.17 t/ha) and sucrose content in juice (17.3). Sulphur levels significantly improved the uptake of P and S up to 80 kg S/ha and the increase was 21.4 and 22.2 over the control respectively. Application of 120 kg S/ha recorded maximum P-use efficiency (361.6 kg cane/kg S applied) and apparent P recovery (8.75), but it recorded S-use efficiency (121.6 kg cane/kg S applied) up to 80 kg/ha level only. There was decrease in apparent S recovery with successive increase in S level from 40 to 120 kg S/ha