环塔盆地不同施氮量对滴灌核桃生长及产量的影响

为解决新疆核桃树在氮肥利用上存在的高耗低效问题,探讨滴灌条件下不同施氮量对核桃生长及产量的影响,于2016年新疆农业大学林果实验基地开展滴灌核桃大田试验。以9 a生新温"185"核桃树为研究对象,设置3个氮肥(含氮量)梯度(低肥N1 0.37 kg/株,中肥N2 0.74 kg/株,高肥N3 1.47 kg/株),研究了滴灌条件下不同施氮量对核桃叶片SPAD值、叶面积指数、果实体积、产量及品质的影响,分析了不同施氮量下水、氮利用效率。试验结果表明:随着施氮量的增加,核桃的叶片SPAD值和叶面积指数呈现先增后减的趋势;果实体积增加至恒定后表现为:N2N3N1。低肥和中肥处理下核桃的个数、产量和出仁率均差异显著,说明增加施氮量显著提高了核桃产出;而高肥处理下产量和中肥处理无显著性差异,核桃产量在中肥处理下达到最大值,为2 854.38 kg/hm~2。蛋白质和脂肪在三种氮肥水平下无显著性差异;中肥处理下水分利用率最高;氮肥偏生产力与施氮量显著负相关。因此在环塔盆地滴灌条件下,中肥处理N2,即每株核桃施氮0.74 kg为最佳的施肥量。研究结果对类似地区核桃滴灌施肥管理具有参考意义。

Effects of different nitrogen application rates on growth and yield of walnut under drip irrigation condition around Tarim Basin

In order to solve the problem of high consumption and low efficiency from the application of nitrogen fertilizer to walnut tree in Xinjiang，a field experiment on the walnut under drip irrigation was carried out in the Fruit Trees Experimental Base of Xinjiang Agricultural University in 2016 for discussing the effects of different nitrogen application rates on the growth and yield of walnut under drip irrigation． By taking 9-year-old walnut tree ( variety‘Wen 185’) as the study object，three nitrogen fertilizer application rates ( nitrogen contents) ，i． e． N1-low application rate－0. 37 kg /plant，N2-medium application rate－0. 74 kg /plant，and N3-high application rate－1. 47 kg /plant，were set up for studying the effects of different nitrogen application rates on SPAD value，leaf area index，fruit volume，yield and quality of walnut under drip irrigation condition and analyzing the water and nitrogen utilization efficiencies of different nitrogen application rates． The experimental result shows that the SPAD value，leaf area index of walnut exhibit increases at first and then decreases along with the increase of the nitrogen fertilizer application rate，while the walnut fruit volume from increase to constant shows an order of N2＞ N3＞ N1． Significant difference is there among the numbers，yields and kernel yields of walnut under the treatments of both the low and the medium fertilizer application rates，which indicates that the yield of walnut is significantly increased by the increase of nitrogen application rate，while no significant difference of the yield is there between the treatments with high and medium fertilizer application rates and the walnut yield reaches to the maximum value of 2854. 38 kg /hm2 under the treatment with the medium fertilizer application rate． No significant difference is there between protein and fat at three levels of nitrogen fertilizer application rates，while the water utilization efficiency is the highest under the treatment of medium fertilizer application rate ( N2) ，moreover，the nitrogen partial factor productivity is negatively correlated with the nitrogen fertilizer application rate． Therefore，the treatment with N2-medium application rate－0. 74 kg / plant is the optimal fertilizer application rate under the drip irrigation condition around Tarim Basin． This study result has a referential significance for the management of the fertilizer application to the walnut under the drip irrigation condition in the similar regions．