Effect of potassium source and level on cotton productivity and soil chemical properties.

摘要

Two field experiments were conducted in Minia Governorate, Egypt during 2003/2004 to compare the effects of two sources of K (potassium sulfate and potassium chloride), each in 3 rates (0, 24 and 48 kg K2O/fed), on N, P and K contents of leaves, yield and yield components of Giza 83 cotton cultivar, and some chemical properties of soil after cotton harvest. The application of K fertilizers at 48 kg/ha exhibited a marked and significant increase in N, P and K content in leaves, number of open bolls per plant, boll weight, seed index, lint index and seed cotton yield, but it decreased lint% compared with the control. A lower rate of K gave similar trend of effects. Soil analysis after harvest of cotton revealed that both K fertilizers especially the higher rate increased available K in the soil. Soil soluble Cl was decreased by sulfate but it was slightly increased by the maximum rate of potassium chloride. Soil electrical conductivity was decreased by potassium sulfate and slightly affected by potassium chloride. It is concluded that the application of 48 kg K2O/fed is of considerable importance for getting maximum cotton yield instead of potassium sulfate. However, the price was much higher thus potassium chloride represents a cheap and effective source of K for cotton..