QUANTITY-INTENSITY RELATIONSHIPS OF POTASSIUM IN NON-FERTILIZED SOILS CULTIVATED WITH VANILLA (Vanilla planifolia Jacks. ex Andrews)

Abstract

Although vanilla is a very profitable and demanded crop, scarce information regarding its nutrient requirements is available.
Immediate available K is related to intensity factor, while reserveness of non-exchangeable K is the quantity factor. Potassium
exchange-equilibrium parameters were outcome from quantity-intensity relationships. No strong differences were found
on exchangeable K, but when the ratio of exchangeable K, Ca and Mg are considered two types of soils can be separated.
Potassium availability depends on a sort of factors. Exchangeable energy for soil with high availability of K (-3.737 kcal)
contrasts with low K availability (-6.876 kcal). Low capacity factor soils may release up to 390 mg kg^-1, but low availability
soils can release up to 900 mg kg^-1.