Guan'gai paishui xuebao (Dec 2023)
Effect of Water and Nitrogen Transport on Sweet Potato Quality, Yield and Soil Water and Nitrogen Distribution under Drip Irrigation with Plastic Mulch
Abstract
【Objective】 This study aimed to investigate the water consumption and growth characteristics of sweet potato under drip irrigation, and to clarify the influence of water and nitrogen regulation on sweet potato quality, yield and water and nitrogen utilization. 【Method】 A two-factor split-plot design was used in the experiment, with 3 irrigation levels (0, 800, 1 600 m3/hm2, denoted as W1, W2, W3) and four nitrogen application levels (0, 120, 240, 360 kg/hm2, denoted as N0, N1, N2, N3). The effects of irrigation and nitrogen levels on sweet potato dry matter accumulation, yield, quality, and water-nitrogen use efficiency were studied. 【Result】 Increasing the irrigation volume can significantly increase the soil water content within 0~60 cm, reduce the amount of nitrate nitrogen and ammonium nitrogen in the soil, and promote the flow and transformation of nutrients in the soil. Soil nitrogen was mainly dominated by nitrate nitrogen, and the amount of nitrate nitrogen in 0~60 cm soil under different treatments increased with the increase of nitrogen application; The total dry matter of sweet potato in all fertility periods increased with the increase of irrigation volume, and showed a trend of increasing and then decreasing with the increase of N application, and the N3 treatment would inhibit the accumulation of dry matter volume; Irrigation volume and nitrogen application and their interactions had significant effects on the nutrient composition of sweet potato, the amount of soluble sugar of sweet potato increased with the increase of nitrogen application, the amount of starch and crude protein showed a tendency of increasing and then decreasing with the increase of nitrogen application, and the amount of starch and crude protein under the treatment of W3N3 decreased by 3.97% and 14.27%, respectively, compared with that under the treatment of W3N2; The sweet potato yield and water and nitrogen use efficiency varied significantly among different treatments, and the sweet potato yield, water use efficiency and nitrogen agronomic utilization were highest in the W3N2 treatment, which increased by 7.81%~61.61%, 0.38%~21.51% and 20.23~145.61%, respectively, compared with the other treatments. 【Conclusion】 In this study, the most suitable irrigation volume for sweet potato growth was 1 600 m3/hm2, and the nitrogen application rate was 240 kg/hm2, which promoted the increase of sweet potato yield on the basis of ensuring the efficiency of water and nitrogen utilization.
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