Response of Glycine wightii to molybdenized superphosphate on a krasnozem

Abstract

The nutrient requirements of Glycine wightii CV. Clarence were investigated on a krasnozem soil near Lismore, New South Wales. Glycine responded to molybdenum, phosphorus, sulphur, and lime when grown in glasshouse pots. Applied in combination, these nutrients increased dry matter yield of plant tops by a factor 2.4 and nitrogen yield by 3.9. A positive interaction between molybdenum and phosphorus was recorded. Growth of plant tops, roots, and nitrogen yield continued to increase in response to molybdenum applied at 0, 1.6, and 3.2 oa an acre. The lime X molybdenum interaction was negative, but lime increased dry matter yield of glycine in the presence of adequate molybdenum. When glycine was sown with Setaria anceps CV. Kazungula in the field, maximum response of glycine was obtained in the following season, by applying molybdenurr, at 6.5 oz and superphosphate at 8 hundredweight an acre at sowing. The response to fertilizer by glycine was not reflected in total yield of the pasture, due to the low proportion (14 per cent) of the legume in the sward. Glycine contributed only 15 lb of nitrogen an acre to the total sward yield of 85 lb an acre over fourteen months. The effect of the nutrient constituents of molybdenixed superphosphate, the problem of grass dominance and other factors were discussed in relation to the low dry matter and nitrogen yields of glycine grown on krasnoxem soil.