氮肥深施对旱作覆膜农田土壤养分含量及春玉米产量的影响

以春玉米为供试作物，于2021—2022年在甘肃省定西市进行不同深度施肥田间试验，以双垄沟覆膜种植为基础，设置3个氮肥施用深度：5 cm(D5)、15 cm(D15)和25 cm(D25),以不施氮(N0)处理为对照，共4个处理，分析不同氮肥施用深度对农田土壤养分含量、干物质积累、水分利用及玉米产量的影响，为优化施肥模式和进一步提升其节水增产效能提供理论依据。结果表明，随施肥深度的增加，农田0～40 cm土层土壤养分含量逐渐增大，D25处理较D15和D5处理的土壤有机碳、全氮、速效磷和速效钾含量分别平均提高8.67%、2.23%、22.11%和15.18%;氮肥深施可提高生育后期养分供给能力，玉米干物质积累量显著提高，D25处理播后105 d～收获期干物质积累量分别较D15和D5提高6.53%和25.30%;2个试验年份农田耗水量和水分利用效率均随着施肥深度的增加逐渐增大，D25处理分别较D15和D5平均提高10.09%和10.08%;D25处理玉米生物产量和经济产量较D5处理分别平均提高27.20%和34.93%。在西北旱作区，氮肥25 cm深施模式能为玉米提供更好的养分供给，是提高...

Effects of deep application of nitrogen fertilizer on soil nutrient content and spring maize yield in dryland film mulched farmland

A field experiment with three nitrogen fertilizer application depths (D5: 5 cm, D15: 15 cm, and D25: 25 cm) and no nitrogen (N0) under double ridge and furrow plastic film mulching planting was carried out in Dingxi City, Gansu Province in 2021-2022. The effects of different nitrogen fertilizer application depths on soil nutrient content, dry matter accumulation, water use and maize yield were analyzed in order to provide a theoretical basis for optimizing fertilizer application mode and further improve its water\|saving and yield\|increasing efficiency. The results showed that with the increase of fertilization depth, the soil nutrient content in 0~40 cm was gradually increased. Compared with D15 and D5, the soil organic carbon, total nitrogen, available phosphorus and available potassium contents under D25 treatment were increased by 8.67%, 2.23%, 22.11% and 15.18%, respectively. The dry matter accumulation of maize was also significantly increased with the increase of fertilization depth, and D25 was 6.53% and 25.30% higher than D15 and D5 from 105 d after sowing to harvest, respectively. Each depth of fertilization treatment increased the water consumption and water use efficiency (P<0.05), which both gradually increased with the increase of fertilization depth. Compared with D5, the biomass and economic yield of maize under D25 were increased by 27.20% and 34.93%, respectively. These results showed that nitrogen fertilizer application at 25 cm depth can effectively improve soil nutrient content and water use efficiency, which is an effective measure to improve the maize yield under film\|mulched farmland in northwest of China.