Effect and mechanism of humic acid compound fertilizer on the drought- and senility- resistant ability of wheat

The effect of humic acid compound fertilizer on the drought- and senility- resistant ability of wheat was studied. The results show that the promotive effect of humic acid on the root activity and extension of wheat is the strongest when the humic acid concentration is 25～50mg／L. In the meantime, the activities of SOD, POD and NR are the highest, the wheat is growing best and the accumulated biomass is the highest. The experiment of soil culture shows that the activity of SOD and the content of proline in wheat are significantly improved and the relative permeability of plasma membrane of wheat is reduced by comparing the application of humic acid compound fertilizer with that of equal nutrients chemical fertilizer. All these are beneficial to promoting the drought- and senility- resistant ability of wheat and increasing the accumulation of dry matter. The relationship between fertilizer rate and above-mentioned physiological item is described with quadratic curve regression model. The highest fertilizer rate is 2.9～4.3g／pot.