Abstract:To explore the effects of digestate application on tomato growth and soil environment during the whole growing period of crop, the influences of digestate application ratio and irrigation amounts on tomato agronomic characteristics, quality, yield, soil physical, chemical environment and biological characteristics were systematically studied. The results showed that the plant height, stem diameter and leaf area of T3 treatment (digestate ratio was 1∶4, and croppan coefficient (Kc) was 10) were the greatest, which were 24.11%, 15.59% and 33.92% higher than those of treatment C0 irrigated with water only, respectively. The application of digestate can increase the yield, quality and taste of tomato, in which the treatment of T2 (digestate ratio was 1∶4, and Kc was 0.8) obtained the highest vitamin C and total soluble sugar content. Meanwhile, digestate application can decrease the soil bulk density and pH value, and subsequently increase the soil total porosity and saturated hydraulic conductivity. The content of soil organic matter was firstly increased and then decreased with the increase of soil depth in treatments applied with digestate. Furthermore, the application of digestate can also increase the number of bacteria, fungi and actinomycetes in each growth period of tomato, in which the quantity of soil bacteria and fungi presented an increase trend from seedling stage to fruit swelling stage, where they reached the peak value and then decreased, while the peak value of actinomycetes quantities appeared at fruit ripening stage. The activities of catalase, invertase and urease in the soil of tomato root zone presented the trend of increase continuously, first increase and then decrease, and first decrease and then increase during the whole growth period, and the peak value of them appeared at fruit ripening stage, fruit enlargement stage, flowering and fruiting stage, respectively. T2 treatment was more conducive to tomato growth when the agronomic traits, quality and yield, and soil biological characteristics of tomato were comprehensively analyzed.
