微润灌施下施氮方式对空心菜生长及水氮利用效率的影响

Effect of N Application Method Under Moistube Irrigation on the Growth Process and Water and N Use Efficiency of Water Spinach

为探寻微润灌施条件下大棚空心菜高产高效模式,进行大棚空心菜种植试验,试验设置压力水头为1.5 m,施氮方式分别为全生育期不施氮(CK);全生育期施氮浓度为300 mg/L(T1);生长前期施氮浓度为300 mg/L,中后期施氮浓度分别为600 mg/L(T2)、900 mg/L(T3)和1200 mg/L(T4)。对不同处理土壤硝态氮含量、空心菜株高、茎粗、产量等指标进行测定,研究不同施氮方式对空心菜生长状况、水氮利用情况的影响。结果表明:不同施氮方式对空心菜生长状况影响显著,T1至T4处理空心菜长势显著优于CK处理,空心菜株高、茎粗随施氮量增加先增大后减小,叶片SPAD值随施氮量的增大而增大;不同处理土壤硝态氮含量随时间增大先增长后下降,不同施氮方式对土壤硝态氮含量影响显著,土壤硝态氮含量随施氮量的增加而增大;不同处理空心菜产量:T2>T3>T1>T4>CK,灌溉水分生产率:T2>T1>T3>CK>T4,T1、T2处理的氮肥农学利用效率显著大于其他处理。综合空心菜的生长指标和水氮利用效率,T2处理是微润灌溉空心菜种植的最佳施氮方式。

The experiment was conducted to find out the high-yielding and high-efficiency mode of greenhouse water spinach under moistube irrigation conditions.N was applied at 300 mg/L at the first stage of growth and 600 mg/L(T2),900 mg/L(T3)and 1200 mg/L(T4)at the middle and late stages,respectively.Soil nitrate nitrogen content,height,stem thickness and yield of hollow cabbage were measured in different treatments to study the effects of different nitrogen application methods on the growth condition and water nitrogen utilization of hollow cabbage.The results showed that different nitrogen application methods had a significant effect on the growth of water spinach.The growth of water spinach was significantly better in the T1 to T4 treatments than in the CK treatment.The plant height and stem diameter of water spinach first increased and then decreased with the increase of nitrogen application,and the leaf SPAD value increased with nitrogen application.The soil nitrate nitrogen content of different treatments firstly increased and then decreased with the increase of time.Different nitrogen application methods had a significant effect on the soil nitrate nitrogen content,and the soil nitrate nitrogen content increased with the increase of nitrogen application rate.The order of water spinach yield of different treatments is T2>T3>T1>T4>CK,the order of irrigation water productivity is T2>T1>T3>CK>T4.The nitrogen fertilizer agronomic use efficiency of T1 and T2 treatments was significantly higher than that of other treatments.Considering the growth index and water and nitrogen use efficiency of water spinach,T2 treatment was the best nitrogen application method for moistube irrigation water spinach planting.