Potassium Fractions and Rice Yield in Different Agro-ecological Zones of Bangladesh

Abstract

Response of Potassium (K) is boosted due to the introduction of high-yielding varieties and cropping intensity. So, a pot experiment was done to see the allocation of native and added K in soils and the response of this on rice. Seven soil samples from seven AEZs. An amount of 1-kilogram soil was taken in each of 28 earthen pots of which 14 pots for cultivation rice and 14 pots for without cultivation as a control. Potassium and other fertilizers applied as follows Fertilizer Recommendation Guide-1012. Two replicate plots were used per treatment. Then the soils were saturated with water so that the soils could be soaked well. The pots were kept in this condition for one day to allow the soils to settle in the pots properly. The rice variety used for the experiment was BRRI dhan28. All forms of K were found to remarkable decrease due to cultivation. The depleted non-exchangeable K sum was the largest, this was followed by exchangeable and then, in control plots, water-soluble K. The depleted amount of exchangeable and non-exchangeable K was almost similar but higher than water-soluble K in treated pots. A significant variation was found among the yields ranging from 3.77 to 5.48 g pot-1. The average dry matter yield of treated pots 4.75 g pot-1 was significantly higher than non-treated pots 3.10 g pot-1.