滴灌条件下不同氮肥处理对红枣生长及产量的影响

Effects of Different Nitrogen Fertilizer Levels on Jujube Growth Indexes and Leaf SPAD Values under Drip Irrigation

为探究滴灌条件下不同氮肥施用水平对枣树生长及产量的影响,并确定适宜当地的氮肥施用量,以民勤当地7 a生枣树为研究对象,设置4个氮肥施用水平(407 kg/hm^(2),CK;610 kg/hm^(2),T1;814 kg/hm^(2),T2;1020 kg/hm^(2),T3)作为处理进行大田试验。结果表明:各生育时期叶片SPAD值均随着施氮量的增加而上升;氮肥量的增加可以在一定程度上促进枣吊的生长,T3处理较CK枣吊长度增加了16.75 cm,增幅为11.57%;增施氮肥可有效提高当地枣树坐果率,坐果率最高的处理为T3,比CK和T1的坐果率分别增加了3.69%和3.06%;T3处理下红枣产量最高,较CK处理增产2444.44 kg/hm^(2),增幅为24.76%。通过使用隶属函数法进行综合评价,认为T3处理(1020 kg/hm^(2)氮肥施用量)为最优处理,是适宜当地的氮肥施用水平。

In order to explore the effects of different nitrogen fertilizer levels on the growth indexes and SPAD value of jujube under drip irrigation,and determine the appropriate local nitrogen application rate,the field experiment was conducted with 7-year-old jujube trees in Minqin,and four nitrogen fertilizer levels(407 kg/hm^(2),CK;610 kg/hm^(2),T1;814 kg/hm^(2),T2;1020 kg/hm^(2),T3)were set as the treatment.The results showed that the SPAD value of leaves increased with the increase in nitrogen application rate in each growth period.The increase in nitrogen fertilizer can promote the growth of jujube bearing branches to a certain extent.Compared with CK,T3 treatment can increase the length of jujube bearing branches by 16.75 cm,an increase of 11.57%.Increasing nitrogen fertilizer can effectively improve the fruit setting rate of local jujube trees,and T3 has the highest fruit setting rate.Compared with CK and T1,the fruit setting rate increases by 3.69%and 3.06%respectively.T3 treatment has the highest yield,which is 162.99 kg/m^(2) higher than CK treatment,with an increase of 24.76%.Through the comprehensive evaluation by using the membership function method,it is considered that T3 treatment(1020 kg/hm^(2) nitrogen fertilizer application rate)is the optimal treatment and is suitable for the local nitrogen fertilizer application.