Study on Effect of Potassium Fertilizer on Cotton in Hubei Province

In 17 field trials, the effects of potassium (K) fertilization on yield, economic benefit, K use efficiency and optimum K recommendation rate of cotton in Hubei province were studied. The results indicated that the yield and profit of cotton significantly increased when K supplied adequately. Compared with the treatment without K fertilizer, K application increased the yield from 129 to 930 kg / hm2 for all sites except one site, which showed no effect when K fertilizer was applied. The average yield increased 445 kg / hm2 and the average increment rate of 16.6 percent for K application. The average net profit and the value cost ratio (VCR) of the K application treatment were 2 128 Yuan (RMB) / hm2 and 4.55, respectively. The average partial factor productivity of applied K(PFPK) and agronomic K use efficiency (AKUE) were 22.77 kg / kg(K2O) and 2.74 kg / kg(K2O), respectively. According to linear plus platform model, the average optimum K application rate was 61.8 kg(K2O) / hm2 on cotton field in Hubei province.