不同渗灌方法和氮肥用量对保护地黄瓜产量及氮肥利用率的影响

Effects of Subsurface Irrigation Methods and Different Nitrogen Application Amounts on Cucumber Yield and Nitrogen Use Efficiency in Protected Field

用保护地田间小区试验的方法,研究节点渗灌与普通渗灌及不同氮肥用量对黄瓜产量及氮肥利用率的影响,以期为保护地生产选择灌溉方法和确定适宜氮肥用量提供依据。试验采用裂区设计,灌溉方法为主区,氮肥用量为副区;普通渗灌、节点渗灌的计划湿润层深度、灌水控制上限和下限等灌水参数相同,氮肥用量（N素）设0,75,225,375,525 kg.hm-2共5个水平。用方差分析、回归分析方法比较各处理间黄瓜产量、氮肥利用率差异显著性,用土壤含水量剖面观测结果分析了产生这一差异的原因。结果表明：无论是普通渗灌、还是节点渗灌,黄瓜产量随氮肥用量增加均呈先增加、再下降的变化趋势,且均以375kg.hm-2施氮处理最高,分别为82878.06kg.hm-2和104664.77kg.hm-2;但在相同氮肥用量条件下,节点渗灌处理的黄瓜产量、氮肥利用率均显著高于普通渗灌。节点渗灌处理的黄瓜氮肥利用率和氮肥农学效率分别较普通渗灌处理提高4.82%和60.98%。这是由于以不同灌溉方法灌水其土壤含水量剖面不同,黄瓜生长的水肥耦合效应不同,灌水后节点渗灌水分主要分布于15~25cm土层,而普通渗灌主要分布于25~35cm土层。保护地蔬菜栽培选用节点渗灌方法灌溉并进行灌溉施肥,能较好地发挥水肥耦合效应;节点渗灌与普通渗灌相比高产、节肥效果更好,且栽培黄瓜适宜施氮量以375g.hm-2为宜。

A field plot experiment on protected field was to study the effects of sectional subsurface irrigation,common subsurface irrigation and different nitrogen application on yield and nitrogen use efficiency,in order to choose irrigation method and suitable nitrogen amount.Split-plot experimental treatments were a factorial combination of two irrigation scheduling regimes and five nitrogen application rates（0,75,225,375and 525 kg·hm-1）.The main plot was irrigation method and the subplot was nitrogen application amount.All plots had the same low and high irrigation limits and planned moisture layer.Significance of yield and nitrogen use efficiency of all plots is compared in the method of analysis of variance and regression analysis.The results showed that the increase of nitrogen amount,cucumber yield of sectional subsurface irrigation and common subsurface irrigation had a trend of rise first then fall,and the yield of treatment 375kgN·hm-1 was the highest,82878.06 kg·hm-1 and 104664.77 kg·hm-1 respectively.Cucumber yield and nitrogen use efficiency of sectional subsurface irrigation were significantly higher than those of common subsurface irrigation in the same nitrogen fertilizer conditions.Cucumber recovery efficiency of applied nitrogen and agronomic efficiency of applied nitrogen of sectional subsurface irrigation were 4.82 % and 60.98 %higher than those of common subsurface irrigation respectively.This was due to different soil moisture profile of different irrigation methods and a difference coupling effect of water and fertilizer.Soil moisture of sectional subsurface irrigation distribut mainly in 15-25cm soil layer,while that of common subsurface irrigation distribute mainly in 25-35cm soil layer after irrigation.Protected vegetable cultivation should select sectional subsurface irrigation for irrigation and fertilization that could play a better coupling effect of water and fertilizer.Compared with common subsurface irrigation,cucumber yield and nitrogen use efficiency of sectional subsurface irrigation were better,and the appropriate optimum amount of nitrogen in cucumber cultivation was about 375 kg·hm-1.