再生水灌溉条件下减量追氮对设施番茄根层土壤氮素利用的影响

为探讨再生水灌溉减量追氮对于设施番茄生产的可行性，以期确定再生水灌溉设施番茄合理氮肥追施量。通过田间小区试验，对再生水灌溉不同氮肥追施水平根层土壤氮素残留、 番茄生物量、 产量、 氮肥偏生产力及表观氮素损失量进行了对比分析。研究结果表明，设施番茄土壤矿质氮的消耗主要集中在30 cm以上根层土壤；与常规氮肥追施处理相比，减量追氮处理，可协调番茄营养生长和生殖生长平衡，番茄产量增加明显，同时显著提高氮肥偏生产力；番茄收获后，减量追氮处理的表观氮素损失量显著低于常规氮肥追施处理。因此，减少氮肥追施量辅以再生水灌溉可以实现番茄产量和氮肥偏生产力同步提升。

Root-layer soil nitrogen use of greenhouse tomato under reducing nitrogen topdressing with reclaimed water irrigation

Field experiments were carried out to clarify the effects of reducing nitrogen topdressing with reclaimed water irrigation on root layer soil nitrogen residual of greenhouse tomato. Root layer soil mineral nitrogen residual, total nitrogen residual, plant biomass, tomato yield, partial factor productivity from applied N and apparent N loss of all treatments were analyzed. The results indicated that soil mineral nitrogen consumption of greenhouse tomato was mainly concentrated in 0 to 30 cm root layer, and compared with the conventional topdressing application with reclaimed water irrigation treatment, the yield and partial factor productivities from the applied N of the reducing nitrogen topdressing treatments were significantly improved. After the post harvest of tomato, soil apparent N loss of the reducing topdressing was significantly less than that of the conventional topdressing. Tomato yield is therefore notably improved under reducing nitrogen topdressing with reclaimed water irrigation, maintaining soil fertility, and which is an effective nitrogen management strategy of alleviating soil environment.