EFFICIENCY OF THE PHOSPHATE ROCK ENRICHED ORGANIC COMPOST APPLICATION IN COTTON

A 3-yr field experiment was carried out in conditions of the old irrigated typical sierozem soil of Tashkent Province, Uzbekistan to investigate application efficiency of the phosphate rock (PR) enriched organic compost from farmyard manure (FYM) on cotton productivity (Gossypium hirsutum L., cv. Akdarya-6). Compared to control treatment with fertilizer rate of N200К100 kg ha-1 , application of the phosphate rock enriched compost with rate of 150 kg Р2О5 ha-1 resulted in increased content of available phosphorus in the soil, better cotton development and accumulation of aboveground biomass (AGB) and higher seed-lint yield. The cotton seed-lint yields were not statistically different in 2003 and 2004 when the compost and ammonium phosphate as individual treatments for comparison were applied with rate of 150 kg Р2О5 ha-1 . However, effect of the compost on seed-lint yield was superior compared to the ammonium phosphate treatment in 2005.