Response of N, P and fertilization on non nodulated soybean CV. Halesoy 71

Abstract

The effect of N, P and NP upon grain and stalk production of nonnodulated soybeans cv. Halesoy 71, was evaluated. Test were carried out during the 1974-1975 season in the Experimental Field of the College of Agrarian Sciences in Rosario, located in Zavalla, Santa Fe. The soil (in this locality) is a Brunizem, class II according to its utilization capacity. The experimental design consisted of randomized blocks with four replication. The P was applied in furrows in the form of Tribasic Calcium Phosphate at sowing time, while N (urea) was placed at the plant base at the time of flower sprouting. The response of non-nodulated soybeans to N application was lineal for grain production, showing a 21% increase at the highest rate utilised (125 kg/N/ha). This increment was significant with respect to the non-nodulated control plant. The production of unfertilized nodulate soybeans was 33% greated than that of the control plants, which was considered to be highly significant. Increased P rate reduced grain production as low as 10,5% for the 100 kg/P/ha rate. The control treatment could only be exceeded in 4% with 150 kg/P/ha, with was the highest rate tried. These difference were not significant All N and P combination increased grain production. The maximum dose of 100 kg of N and 100 kgof P brought about an increment of 18% which was a statistically significant difference. Stalk yield was lower in the fertilizer plots, regardless of the fertilizer used and of the dosis applied. The relation stalk weight/grain weight, decreased with higher fertilizer doses and its was due, in the case of the fertilization with N and NP, to decrease in stalk production and increment in grain yield, and for P, to a higher decrease in the production of stalk than that of grain.