EFFECT OF HUMIC ACID COMBINED WITH FERTILIZER ON THE IMPROVEMENT OF SALINE-ALKALI LAND AND COTTON GROWTH

The effect of humic acid combined with fertilizer is an important basis for improving the soil's ecological environment.Therefore, this study is aimed at investigating the effect of the combined application of humic acid and fertilizer on the physicochemical properties of saline-alkali soil, cotton growth, and nutrient utilization in an arid area.The random field block test method was adopted, and biochemical humic acid (BHA), ammoniated humic acid (AHA), and microbial activated humic acid (MHA) were used as experimental materials.Soil pH, electrical conductivity (EC), water-soluble cation content, soluble nitrogen content, available phosphorus content, cotton biomass, and yield were determined.The results showed that humic acid combined with fertilizer had no obvious effect on the pH of the salinized soil.However, the addition of three types of humic acid showed a certain reduction effect on soil EC, water-soluble Na + and K + content, and sodium adsorption ratio (SAR), affecting the soil depth of 0-40 cm.In addition, the content of available phosphorus in soil could be increased by adding three humic acids, among which MHA was the best.The addition of humic acid could significantly improve the yield of cotton, but there was no significant difference between the three.