Abstract

This study reports the effects of magnesium (Mg) and phosphorus (P) fertilizer dosage and different water levels, on the plant growth, yield and quality factors of soybean. The field study used a random block design with three replications and was conducted over two years, 2006 and 2007. Four different P doses (0-4-8-12 kg P da^-1) and three different Mg doses (0-4-8 kg Mg da^-1) were applied with three different water levels (I₁, I₂, I₃). Cumulative pan values obtained from a Class A pan evaporation pool were 33% for I_1, 67% for I₂, and 100% for I₃. Yield per decare (da), thousand-grain weight, harvest index, soil biomass, oil content, and protein content increased with increased water, phosphorus and magnesium levels. Increased water levels did not affect root and stem dry items amount dry mass, however, the similar features increased with increased Mg and P levels.

Key words: Glycine max L., water level, phosphorus, magnesium, productivity, quality.