膜下滴灌水氮调控对甘薯品质、产量及土壤水氮分布的影响

Abstract

【目的】探究甘薯在膜下滴灌条件下的需、耗水规律与生长特征，明晰水氮调控对甘薯品质、产量及土壤水氮分布的影响。【方法】基于二因素田间裂区试验，设置3个滴灌水平（0、800、1 600 m3/hm2，分别记为W1、W2、W3）和4个施氮水平（0、120、240、360 kg/hm2，分别记为N0、N1、N2、N3），研究灌水量和施氮量对甘薯干物质量、产量、品质及水氮利用效率的影响。【结果】增加灌水量能够显著提高0~60 cm土层的土壤含水率，降低土壤硝态氮、铵态氮量，促进土壤养分流动与转化。土壤氮素的赋存形态以硝态氮为主，0~60 cm土层的土壤硝态氮量随施氮量的增加而升高；甘薯干物质量随灌水量的增加而增大，随施氮量的增加呈先增后减的变化趋势。灌水量、施氮量及其交互作用对甘薯营养成分均有显著影响，甘薯可溶性糖量随施氮量的增加而增加，淀粉量与粗蛋白量随施氮量的增加呈先增后减的变化趋势，W3N3处理下的淀粉量与粗蛋白量相比W3N2处理分别降低了3.97%、14.27%；不同处理下的甘薯产量与水氮利用效率差异显著，甘薯产量、水分利用效率和氮素农学利用效率在W3N2处理下最高,分别相比其他处理提高了7.81%~61.61%、0.38%~21.51%和20.23~145.61%。【结论】本试验条件下，适宜甘薯生长的最佳灌水量为1 600 m3/hm2，最佳施氮量为240 kg/hm2，在保证水氮利用效率的同时可促进甘薯增产。

Alternate 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 three 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 from 0 to 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.