Fertilisation soufrée du soja

Abstract

The effect of S (60, 120 and 240 kg ha−1) and N (45 and 90 kg ha−1) fertilization on the yield and quality of soybean (Glycine max L. Merrill ’Maple Amber’), grown on a Kamouraska silty clay loam, was studied under greenhouse conditions, and in the field over a period of 2 yr. In the greenhouse, soybean (dry matter and pod weights) was responsive to N and S, and an excess of sulfate reduced P and K levels in the upper leaves. In the field, small or nonsignificant differences between fertilizer treatments were found for yield parameters in 1988 and 1989. However, as compared to the 45-kg ha−1 application rate, application of 90 kg N ha−1 decreased methionine concentration in the grain in 1989, when yield was low. Thus, excessive N reduced the nutritive value of soybean without affecting yield.Key words: Protein, oil, amino acids, nutritive value of soybean