滴灌施肥时机对设施蔬菜产量品质与氮肥利用效率的影响

Effects of Drip Fertigation Strategies on Yield and Quality of Protected Vegetables and Nitrogen Use Efficiency

为了提高设施蔬菜滴灌水肥利用效率,在日光温室内开展了为期15个月不同滴灌施肥时机对设施蔬菜产量品质、土壤-蔬菜系统中氮素分布、氮素平衡和氮素利用效率的研究。结果表明:滴灌施肥时机对果实产量、全氮和硝酸盐含量有显著影响,灌水中前期施肥处理产量、全氮和硝酸盐含量均较高,随着施肥时段向后推移,蔬菜吸收氮素先增大后减小;灌水后期施肥处理在收获后各层土壤硝态氮含量最低且消耗量最高,灌水中期施肥处理土壤-蔬菜系统表观损失和氮盈余小,较其他处理低15.35%~59.13%;灌水中期施肥处理氮肥偏生产力和氮肥表观利用率高于前后期施肥处理,3茬平均氮肥表观利用率T2处理高于其他处理7.09%,7.41%,11.48%。施肥时机对土壤-蔬菜系统产量品质和氮素分布等综合影响明显,推荐滴灌施肥过程中尽量使施肥时机保持在灌水过程的中期。

In order to improve the water and fertilizer use efficiency of drip fertigation for protected vegetables, the effects of drip fertigation strategies on yield and quality of greenhouse vegetables, and soil nitrogen distribution, nitrogen balance and nitrogen use efficiency in soil-vegetable system were investigated for 15 months in a solar heated greenhouse. The results showed that the fruit yield and the contents of total nitrogen and nitrate were affected significantly by fertigation strategies. The yield, total nitrogen and nitrate content were all higher in the treatment of fertilizing at the early stage of irrigation, and the nitrogen uptake by vegetable increased first and then decreased with the time of fertilization progressing backwards. After harvest, the soil nitrogen contents of the treatment of fertilizing at the end stage of irrigation were the lowest in all soil layers, while the nitrogen consumptions were the highest. In the treatment of fertilizing at the medium stage of irrigation, the apparent loss and surplus of nitrogen in soil-vegetable system were 15.35%~ 59.13% less than those in other treatments. Nitrogen fertilizer partial productivity and nitrogen apparent efficiency of the treatment of fertilizing at the medium irrigation stage were higher than those in other treatments. The average nitrogen fertilizer apparent utilization rate of the three stubbles in the T2 treatment was 7.09%, 7.41% and 11.48% higher than that in other treatments, respectively. In conclusion, fertigation strategies had a significant comprehensive impact on the yield, quality and nitrogen distribution of soil-vegetable system, and the strategy of applying fertilizer at the medium stage of irrigation schedule was recommend.