Effects of Manure on Soil Chemical Properties, Yields, and Chemical Compositions of Chinese Kale Grown in Alluvial and sandy Paddy Soils of Northeast Thailand. II. Nutrient Contents and Relationships with Yields

Abstract

A pot experiment was conducted to study the effects of cow manure on nutrient concentration and uptake of Chinese kale and the relationships between nutrient concentrations and plant yield in plants grown in two different soils. Five rates of cow manure were used, 0, 1, 2, 3, 4 and 5% on a dry weight basis (0, 20, 40, 60, 80 and 100 ton/ha). Cow manure significantly increased the uptake of P and K but not N and Ca. Soil Bray II. Extractable P,P concentration in plant and yields produced significant positive correlation with soil pH in both soils, but the soil with higher original soil P fertility gave lower correlation coefficients than the lower fertility soil. The relationships between nutrient concentrations and yields showed that the critical nutrient concentration was close for plants grown in two different soils with an exception of K. The critical concentration for N found was 2.0 – 2.5% and that for P was 0.22%