Forms and quantity-intensity parameters of potassium under sweet potato cultivation

Sweet potato is an important vegetable and crop food for humans and an important feed for domestic animals as well as an industrial material for producing starch, sugar and alcohol. This study was undertaken to elucidate the magnitude of changes in different forms and quantity-intensity parameters of potassium due to its application at differential rates. Effect of different K levels on K fractions in soils showed that K maintains a dynamic equilibrium in the soil among its various forms. A significantly higher value of available K was recorded at 75 kg ha⁻¹ level compared to 25 and 50 kg K ha⁻¹. The AR_e^K was found to be more closely correlated with yield response to K fertilizer than exchangeable K. The quantity factors such as labile K (K_L), K on non-specific sites (K₀) and K on specific sites (K_X) recorded higher values with increasing K rates, indicating a greater K release into soil solution resulting in a larger pool of labile K