Studies on crop-legume behaviour in pure and mixed stands

Abstract

The behaviour of wheat and Trigonella polycerata L. was studied in pure and mixed stands at two nutrient levels in the soil. Wheat responded to increasing density by extreme plasticity whereas the legume responded both by mortality and plasticity. In mixtures, an increase in the density of T. polycerata resulted in an increased dry weight yield of the crop and only at very high densities of Trigonella was there an adverse effect of the weed on the crop. It is suggested that stimulation of the crop is related to nitrogen enrichment of the soil due to the nodular bacteria in the root of the weed. The legume itself suffered from the presence of the crop. T. polycerata showed considerable interplant variation, the range of variation was greater at low densities and in nutrient-rich soils at a given plant density.