Effects of Aeration on Tomato Growth and Soil Enzyme Activity Under the Conditions of Topdressing Fertilizer Reduction

Abstract

[Objective] The study aimed to explore the effects of aeration on crop growth characteristics and soil environmental characteristics in the root zone under reduced topdressing conditions. [Methods] The present paper took the field cultivated tomato in Yinbei irrigation area of Ningxia as the research object. Four groups of micro-nano gas aeration ratios (0, 5%, 10%, and 15%) and three topdressing fertilizer (urea-triple superphosphate-potassium sulfate) levels (180-400-480 kg/hm2, 135-300-360 kg/hm2, and 90-200-240 kg/hm2) were set up for the two-year field experiment conducted in 2019 and 2020. [Results] With the same topdressing level, the dry matter and nutritional elements (N, P, and K) accumulation in the plant increased with the increase of aeration ratio, and increasing the aeration ratio was beneficial to the accumulation of phosphorus in roots during flowering-fruit setting period and the potassium accumulation at fruit expansion stage. With the same topdressing level, the tomato yield increased by 14.0%~44.2% as the aeration ratio increased by 5%~15%. With the same aeration ratio, the tomato yield increased by 0.4%~9.1% as the topdressing level was appropriately reduced (-25%) compared with the traditional fertilization. The increase of the aeration ratio and topdressing level was beneficial to increase the soil enzymes (catalase, alkaline phosphatase, and urease) activity significantly during the flowering-fruit setting period and fruit enlargement period of tomato. With the same topdressing level, increasing the aeration ratio by 5%~15% corresponded to an increase in soil enzyme activity by 27.5%~122.9%. [Conclusion] It was suggested that, to promote tomato plant growth, stabilize tomato yield and improve the soil enzymes activity in the Yinbei irrigation district, the suitable topdressing level of “urea-triple superphosphate-potassium” was 135-300-360 kg/hm2 (25% lower than the traditional topdressing amount), and the suitable micro-nano aeration ratio was 10%.

Keywords

• subsurface drip irrigation
• aerated irrigation
• micro nano bubbles
• arid and semi-arid areas
• yinbei irrigation area