施用腐植酸复合肥对小麦抗旱防衰能力的影响及其机理

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

试验研究施用腐植酸复合肥对小麦抗旱、防衰能力的影响结果表明，腐植酸浓度为25～50mg／L时对小麦根系伸展与活力的促进作用最强，根内超氧化物歧化酶、过氧化物酶和硝酸还原酶活性最高，麦苗长势最佳且生物量最大。土培条件下腐植酸复合肥比等养分量化肥更显著提高小麦体内超氧化物歧化酶活性与脯氨酸含量，降低质膜透性，有效提高小麦抗旱与防衰能力，增加干物质量累积。施肥量与各生理指标间呈二次曲线相关，峰值施肥量为2．9～4．3g／盆。

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.