Effect of autotoxicity and allelopathy on alfalfa and wheat

The continuous cropping and rotation of alfalfa and wheat seedlings were used to simulate the growth and growth of alfalfa and wheat. The results showed that the concentration of the leaching solution was greater than 0.1 g·L^–1, and that the autotoxic effect increased with an increase in the concentration of the extract solution. When the leaching solution was used for irrigation at 0.1, 0.25, and 0.5 g·L^–1, there was a positive effect of sensation on glutinous wheat, and 0.25 g·L^–1 extract had the strongest positive effect, and the wheat extract had a positive effect on quail. The positive effect on wheat was higher than that of other extracts. At a concentration of 1 g·L^–1, the activities of antioxidant enzymes, including superoxide dismutase, peroxidase, and catalase, showed a continuous decrease, resulting in an increase in malondialdehyde and H₂O₂ content and an enhancement in relative membrane permeability. Furthermore, there was a high accumulation of active oxygen, the living system is maintained to be destroyed, growth was inhibited, and glutinous wheat exhibited negative effects. The autotoxic effect of continuous cropping of alfalfa and wheat, thus, increases with an increase in the concentration of the extract. Low concentrations and high concentrations of extracts affected the rotation-heterogeneity of alfalfa and wheat.