塔里木盆地西北缘区密植核桃的滴灌水肥适宜用量

目的]确定核桃主产区塔里木盆地西北缘区滴灌条件下核桃水肥适宜用量,实现核桃园水肥高效利用,为当地密植核桃滴灌水肥投入量提供指导。方法]以9 a生密植新温"185"核桃树为研究对象,设置3个灌水量(W_1:375 mm; W_2:435 mm; W_3:495 mm)和3个施肥量(F_1:2 250 kg/hm~2; F_2:4 500 kg/hm~2; F_3:9 000 kg/hm~2。其中尿素:磷酸一铵1∶1.25),在新疆阿克苏红旗坡农场新疆农业大学林果实验基地开展滴灌核桃大田试验,研究滴灌条件下水肥耦合对核桃产量、品质及水肥利用效率的影响,建立了水肥投入量与产量及灌溉水利用效率的二元回归模型。结果]灌水和施肥对核桃硬核期、油脂转化期和成熟期土壤硝态氮、核桃产量、品质和水肥利用率的影响均达显著水平(p0.05);水肥耦合效应对核桃产量和水肥利用率有显著性影响(p0.05);硬核期和油脂转化期为核桃的需肥关键期;F_3处理施肥量造成了土壤硝态氮的累积;W_2和W_3处理对滴灌核桃品质、产量和肥料偏生产力的影响无显著性差异,均与W_1差异显著;施肥处理对核桃出仁率、产量和水肥利用效率的影响均达显著水平。结论]新疆环塔盆地滴灌密植核桃全生育期适宜的水肥投入范围分别为438～469 mm(包含冬春灌)和7 074～7 168 kg/hm~2,其中尿素3 144～3 186 kg/hm~2,磷酸一铵3 930～3 982 kg/hm~2。

Suitable Amounts of Water and Fertilizer for Dense Planting of Walnut Trees Under Drip Irrigation in Northwest Margin of Tarim Basin

Objective] The appropriate quantities of water and fertilizer were determined to understand their efficient utilization for walnut trees under drip irrigation in the Northwest Margin of Tarim Basin, which is a main production area of walnuts. The aim was to provide guidance for the extent of irrigation and nitrogen input to be used for drip irrigation for local dense planting of walnut trees.Methods] The field experiment was conducted in the fruit trees experimental base of Xinjiang Agricultural University. Taking the nine-year-old dense planting of walnut trees (variety "Xinwen 185") as the research object, three irrigation levels (W₁:375 mm, W₂:435 mm, W₃:495 mm) and three fertilizer doses (F₁:2 250 kg/hm², F₂:4 500 kg/hm², F₃:9 000 kg/hm²) were arranged to study the effects of water-fertilizer coupling on walnut yield, walnut quality, and water and fertilizer utilization efficiency under drip irrigation. Mathematical models of the relationship between water-fertilizer investment and walnut indicators were established through multiple quadratic regression analysis.Results] The effects of irrigation and fertilizer on the soil NO^-₃-N in the walnut tree growth periods of hard stone and oil conversion, on the walnut yield, quality, irrigation water use efficiency (IWUE), and partial factor productivity (PFP) reached significant levels (p<0.05). The interaction effects of irrigation and fertilizer on walnut yield, IWUE, and PFP reached significant levels (p<0.05). Hard stone and oil conversion periods were the key periods of fertilizer demand for walnut trees. The F₃ treatment resulted in the accumulation of soil nitrate nitrogen. There was no significant difference in the effects of W₂ and W₃ treatments on the quality, yield, and PFP of drip irrigation of walnut trees, which were significantly different from those of W₁. The effects of fertilizer application on the kernel yield, yield, IWUE, and PFP of walnut trees were significant.Conclusion] Around Tarim Basin, the suitable ranges of water and fertilizer applications for the whole growth period of walnut trees were, 438 to 469 mm (including winter and spring irrigation) and 7 074 to 7 168 kg/hm², respectively, including 3 144 to 3 186 kg/hm² urea and 3 930 to 3 982 kg/hm² monoammonium phosphate.