Nutrient management in summer onion (Allium cepa) under cold desert conditions of north western Himalayas

Abstract

A field experinlent was conducted during the summer seasons of 2001, 2002 and 2003 to find out the most viable and sustainable nutrient management system in sunlmer onion at Lari (3 300 m above mean sea-level) on silty loam soil having low organic C and N. The 100% NPK (N:P,O,:K,O:: 120:75:60 kgha) + farmyard manure (100 tonnesiha) +mulch (8 tonneslha) and 100% NPK + farmyard manure resulted in significantly higher plant height, bulb weight, polar diameter, net return and B : C ratio. However, 100% NPK + famyard manure + mulch was superior to 100% NPK + farmyard manure in increasing bulb yield. In general fertilizer treatments including farmyard manure were superior over the treatments without farmyard manure. The 50-75% NPK + farmyard manure resulted in significantly higher bulb yield and net returns over 100% NPK without farmyard manure. But 8 : C ratio following 50% NPK + farmyard manure and 75% NPK + farmyard manure was significantly low compared to 100% NPK without farnlyard manure. The incremental benefit: cost ratio (marginal benefit : cost ratio) was highest for 100% N followed by 100% NPK + farmyard manure, 100% NPK + farmyard manure + mulch and lowest for 50% NPK + farmyard manure. Bulb yield was positively and significantly associated with biological yield, plant height, bulb weight. polar diameter and equatorial diameter.