施氮量对再生水灌溉番茄根际土壤供氮能力影响

为了探明施氮量对再生水灌溉设施番茄根际土壤供氮能力的影响,通过田间小区试验,对不同施氮处理番茄关键生育阶段根际、非根际土壤矿质氮和全氮、番茄生物量和产量、氮肥偏生产力、表观氮素损失量及土壤供氮能力进行了对比分析。研究结果表明,氮肥减施20%处理和氮肥减施30%处理,番茄关键生育期根际土壤矿质氮保持在55mg/kg以上,根际与非根际土壤矿质氮差异介于10.47%～12.63%之间,促进了非根际土壤矿质营养向根际土壤迁移;氮肥减施20%处理和氮肥减施30%处理氮肥偏生产力、作物氮生产力和产量均显著高于常规施氮处理。氮肥追施量控制189～216kg/hm2、辅以再生水灌溉,促进了非根际土壤矿质营养向根际土壤迁移,提高了根际土壤供氮能力,有效削减了0～30cm根层土壤表观氮素损失,保证了番茄关键生育阶段生长对土壤矿质营养需求,显著提高了番茄关键生育阶段氮肥偏生产力和番茄产量。

Nitrogen Topdressing on Rhizosphere Soil Nitrogen Supplying Capacity of Greenhouse Tomato with Reclaimed Water Irrigation

To discuss effects of different nitrogen topdressing on rhizosphere soil nitrogen supplying capacity of greenhouse tomato with reclaimed water irrigation,field experiments were carried on,and rhizosphere soil mineral nitrogen and total nitrogen,non-rhizosphere soil mineral nitrogen and total nitrogen,plant biomass and yields,apparent N loss and nitrogen supplying capacity of key growth stages of different treatments were measured and analyzed.The results indicated that rhizosphere soil mineral nitrogen content remained 55 mg/kg above of tomato key growth stage,and mineral nitrogen content differences between rhizosphere and non-rhizosphere soil were 10.47% to 12.63% of reduced 20% and 30% fertilizing quantity treatment,thus promoting non-rhizosphere mineral nitrogen to rhizosphere migrating,nitrogen use efficiency,crop nitrogen productivity and yield of reduced 20% and 30% fertilizing quantity treatment were significantly higher than conventional nitrogen topdressing treatment.Therefore,nitrogen topdressing in 189 to 216 kg/hm2 with reclaimed water irrigation,effectively reduced apparent N loss of 0 to 30 cm layer,which promoted the non-rhizosphere mineral nutrients to rhizosphere migrating,and ensured rhizosphere soil mineral supplying during key growth stages of tomato,the rhizosphere soil nitrogen supplying capacity,partial factor producitivity from applied N,yield of nitrogen topdressing in 189 to 216 kg/hm2 was significantly improved than conventional nitrogen treatment.