不同水氮用量对日光温室黄瓜季硝态氮淋失的影响

于2010年3～7月,在河北省辛集市马庄农场研究了不同水氮用量对黄瓜季硝态氮淋失的影响,结果表明,通过调节不同生育阶段灌水量使黄瓜全生育期土壤含水量保持在18.7%～22.1%,不仅可以满足黄瓜生长发育对土壤水分的要求,而且可以减少用水量30%。不同处理中以节水灌溉、习惯施氮处理（W2N1）土壤硝态氮含量最高,习惯灌水、减量施氮处理（W1N2）最低。全生育期内,土体95cm深度硝态氮淋失量与土壤含水量、土壤硝态氮含量均呈正相关,其中以初瓜期和盛瓜期相关性系数最高。与农民习惯水氮处理（W1N1）相比,节水减氮处理（W2N2）在节水30%减施氮25%的情况下,可以显著降低黄瓜季土壤硝态氮淋失量,整个生育期降低淋失量35.0%。3年连续试验结果表明,节水减氮处理（W2N2）与习惯水氮处理（W1N1）间黄瓜产量结果差异不显著,说明河北省温室大棚蔬菜生产,目前农民习惯施氮和灌水量有很大的节水节肥空间,根据蔬菜不同生育期需肥量和土壤含水量来合理分配水、氮可取得明显的节水节氮效果。

Effects of different water and nitrogen amounts on nitrate leaching in sunlight greenhouse during cucumber growing season

The study was conducted to determine the effects of water and nitrogen amounts on nitrate leaching during cucumber growing season in a greenhouse in Xinji,Hebei province in 2010.The results indicate that the water-saving treatment which maintains soil moisture contents at 18.7%-22.1% in the whole period can fully meet the demand of water for cucumber growth.The highest value of soil nitrate nitrogen content is achieved in the water-saving and conventional nitrogen rate treatment,and the lowest value is achieved in the conventional water rate and nitrogen-saving treatment.The nitrate nitrogen leaching amount in the depth of 95 cm is closely related to soil moisture and nitrate nitrogen contents during cucumber growing season,especially of the primary fruit stage and full fruit stage.Comprehensive analysis shows that the optimal treatment is W2N2 with 30% reduction in water and 25% reduction in nitrogen compared with the conventional treatment,and the nitrate nitrogen leaching amount is reduced by 35.0% in the whole period.In this study,the yields between the water-saving and nitrogen-saving treatment and the conventional treatment are not significantly different.There are water-saving and nitrogen-saving approaches compared to the conventional treatment of farmers.According to fertilizer demand and soil moisture in different periods,we can gain obvious water-saving and nitrogen-saving effect through the control of water and nitrogen.