Effects of straw amendment fertilizers on water use efficiency,yield and quality of potato

In order to improve the retention capacity of soil, soil structure, and the utilization efficiency of water and fertilizer, three types of straw amendment fertilizers made from corn, wheat and soybean straw treated with physicochemical methods and combined with poly-acrylamide (PAM) respectively were applied to potato cultivation in the field. Meanwhile, their effects on the physical properties, physiological characteristics, yield, quality and water use efficiency were studied, taking no fertilizer and single potash fertilizer for comparison. The results indicated that three types of straw amendment fertilizers all had better water preserving ability, and not only increased significantly the water content of the 0-20 cm surface soil but improved the water content of plough layer and 20-70 cm soil during the seedlings, tuber growth and starch accumulation stage. They decreased effectively the soil bulk density, raised the non-capillary porosity rate and soil porosity, at the full-bloom stage of potato, and also increased dramatically the leaf photosynthetic rate, stomata conductance and transpiration rate. Meanwhile the plant height, crown breadth area and leaf area of the potato were raised. As compared with control groups, the starch content, the rate of big and middle tuber , the potato productivity, and the utilization efficiency of water in the soil increased 12.3%-13.6%, 37.9%-42.8%, 39.3%-50.4% and 35.6%-45.4% respectively on the treatments of three fertilizers. Therefore, straw amendment fertilizers had significant effect on the soil water utilization and potato growth. This study provides theoretical basis for the extension of straw amendment fertilizers.