滴灌枣树水肥一体化对土壤养分动态的影响

Effect of Water and Fertilizer Integration of Jujube Trees under Drip Irrigation on Soil Nutrient Dynamics

滴灌枣树在一定水分条件下,不同肥料配比的土壤养分变化特征,为枣树合理施肥提供理论参考。以7~9年骏枣为研究对象,氮磷钾不同的施肥配比,于萌芽新梢期、花期、坐果期、成熟期滴施;并于花期、坐果期、成熟期取土检测水解性氮含量、有效磷含量、速效钾含量。试验结果表明枣树在坐果期对土壤氮肥需求最高;花期和成熟期需要充足的磷素满足枣树的生殖生长;花期、坐果期需要大量的钾素,尤其在坐果期更要加大钾肥的施入。依据养分变化与产量分析,枣树在混合田间持水量(萌芽期60%,花期、坐果期60%~75%,成熟期55%)作为滴水下限控制指标时,优化出合理施肥方案,其最佳施肥组合处理5纯氮375 Kg/hm2,五氧化二磷243.75 Kg/hm2,氧化钾303.75 Kg/hm2 (比例为1:0.65:0.8)产量最高。

The change characteristics of soil nutrients under drip irrigation jujube under certain water conditions and different fertilizer ratios provide a theoretical reference for rational fertilization of jujube. Taking 7-year-old Jun Jujube as the research object, different fertilization ratios of N, P and K were applied dropwise at the germination and new shoot stage, flowering stage, fruit setting stage and mature stage. The contents of hydrolytic nitrogen, available phosphorus and available potassium were measured at flowering, fruit-setting and mature stages. The results showed that jujube trees needed the most nitrogen fertilizer in the fruit-setting stage, enough phosphorus in the flowering and mature stages to satisfy the reproductive growth of jujube trees, and a large amount of potas-sium in the flowering and fruit-setting stages, especially in the fruit-bearing period to increase the application of potassium fertilizer. According to the analysis of nutrient change and yield, the water holding capacity of Jujube in mixed field (60% at germination stage, 60%~75% at flowering and setting stage, and 55% at maturity stage) was used as the control index of the lower limit of drip water. The optimum fertilization combination treatment was deal with 5 pure nitrogen 375 kg/hm2, tetraphosphorus decaoxide 243.75 kg/hm2, potassium oxide 303.75 kg/hm2 (1:0.65:0.8) had the highest yield.