节水减氮对温室土壤硝态氮与氮素平衡的影响  

Effects of Reduced Application of Nitrogen and Irrigation on Soil Nitrate Nitrogen Content and Nitrogen Balance in Greenhouse Production

作　　者：李若楠[1,2] 武雪萍[1] 张彦才[2] 王丽英[2] 陈丽莉[2] 翟凤芝[2] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所/耕地培育技术国家工程实验室,北京100081 [2]河北省农林科学院农业资源环境研究所,石家庄050051

出　　处：《中国农业科学》2016年第4期695-704,共10页Scientia Agricultura Sinica

基　　金：国家"十二五"科技支撑计划(2015BAD22B03);国家"863"计划(2013AA102901);国家公益性行业(农业)科研专项(201203077);河北省农林科学院科学技术研究与发展计划(A2015130101)

摘　　要：【目的】针对日光温室蔬菜生产中肥水超量施用问题,以提高氮肥利用率和实现温室菜田可持续利用为目标,研究节水减氮在温室蔬菜生产中的增效潜力,推荐适宜水氮用量。【方法】采用当地典型种植茬口冬春茬黄瓜一秋冬茬番茄,在沟灌方式下设计农民习惯灌溉(W_1,>100%田间持水量)和减量灌溉(W_2,75%-95%田间持水量)2个灌水水平;农民习惯施氮(N_1)、较农民习惯减氮25%(N_2)、减氮50%(N_3)和无氮(N_0)4个氮肥水平,对应黄瓜季施氮1200、900、600和0 kg·hm^(-2),番茄季施氮900、675、450和0 kg·hm^(-2),共W_1N_1、W_2N_2、W_2N_3、W_1N_0和W_2N_05个水氮用量组合处理,3年6季定位研究蔬菜关键生育期0-100 cm土体硝态氮动态变化,分析氮素平衡和经济效益,推荐合理水氮用量。【结果】农民习惯水氮管理W_1N_1处理土壤硝态氮积累明显,并向土壤深层迁移。节水减氮W_2N_2处理3年0—60 cm土层硝态氮供应保持在相对适宜水平,平均硝态氮含量为53.3—80.9 mg·kg^(-1);0-100 cm土体硝态氮未出现明显积累,平均含量较W_1N_1处理下降13.9%-31.1%;氮素表观损失下降56%,氮肥利用率提高2.4-3.3个百分点,并保持较高的经济效益。依据0-20 cm土层硝态氮含量与产量之间的显著回归关系,获得最佳产量土壤硝态氮含量黄瓜为37.4-72.9 mg.kg^(-1),番茄应低于90 mg·kg^(-1)。根据蔬菜氮素需求量和关键生长期适宜的土壤硝态氮含量,结合根区土壤水分监测,推荐与供试条件相近的温室,沟灌冬春茬黄瓜产量160-180 t·hm^(-2)下灌水450-550 mm配合施氮600 kg·hm^(-2)较适宜,秋冬茬番茄产量70-80 t·hm^(-2)时灌水170-200 mm配合施氮250 kg·hm^(-2)较适宜。分析水氮减施增效原因为:节水20%-30%使土壤硝态氮趋近根区分布,节氮50%降低土壤剖面硝态氮积累,节水20%-30%配合减氮50%将根区硝态氮供应维持在适宜水平的同时,降低进入损失途径的氮素,从而实现增效[Objective] Excessive applications of nitrogen and irrigation water in greenhouse vegetable production lead to lower nitrogen （N） use efficiency and unsustainable use of land. The aim of this study was to investigate the potential of a saving on N and water in vegetable production and the best combination of N and irrigation rates. [ Method ] An experiment was conducted in a 4-year cultivated greenhouse with winter-spring cucumber and autumn-winter tomato double cropping system. Two irrigation levels as conventional irrigation （Wb 〉 100% field capacity） and reduced irrigation （W2, 75% field capacity） and 4 N levels as conventional N rate （NO, saving 25% N compared to conventional management （Nz）, saving 50% N compared to conventional management （N3） and no nitrogen control （No） was designed. The corresponding N rates were 1200, 900, 600 and 0 kg.hm2 for cucumber season and 900, 675, 450 and 0 kg·hm^-2 for tomato season. Five combination treatments were designed as WIN1, W2N2, W2N3, WxN0, and W2N0 in this experiment. [ Result ] （1） Severe accumulation of NO3^-N was observed in the conventional management, and the NO3^-N was leached away from the surface soil layer. No significant NO3^-N accumulation was observed in W2N3 treatment. The average NO3^-N content in W2N3 treatment at 0-60 cm depth was at the proper level, and the average NO3^-N content at 0-100 cm depth decreased by 13.9%-31.1% compared to W1N1 treatment. Moreover, the apparent N loss decreased by 56% and the N use efficiency increased by 2.4-3.3 percentage point in W2N3 with relatively higher economic benefit. （2） Based on the significant correlations between the NO3^-N content and the yield, the optimal NOa-N contents were 37.4-72.9 mg＇kgx for cucumber growing, and the corresponding values were lower than 90 mg kg^-1 for tomato growing. （3） In order to keep the proper NO3^--N value for uptaking by plants at 0-20 cm depth, 600 kg.hmZof N with 450-550 mm of irrigation were recommended for cucumber with the yiel

关 键 词：温室蔬菜 水氮用量 土壤硝态氮含量 氮肥平衡 经济效益 

分 类 号：S626[农业科学—园艺学] S641.2S642.2