控释氮肥对土壤NH_4~+-N、NO_3~--N及番茄产量和质量的影响

通过温室小区试验 ,研究了日本热塑性树脂包膜尿素MEISTERLP10 0以及LP10 0配施双氰铵 (DCD)后土壤NH+ 4-N、NO-3 -N以及番茄产量和质量的变化。结果表明 ,分次施用尿素会引起土壤NH+ 4-N的急剧变化 ,而施用了LP10 0处理的土壤NH+ 4-N和NO-3 -N在试验的前 115天一直平稳地维持在较高水平 ,且在此之后 ,仍有大量的NH+ 4-N和NO-3 -N存留于土壤。DCD发挥了抑制土壤NH+ 4-N硝化的作用 ,这种作用维持了大约 3个月左右 ,这使土壤NH+ 4-N含量增加 ,而使土壤NO-3 -N的累积量降低 ,这种降低作用尤其表现在 2 0～ 40cm耕层。施用LP10 0并没有取得比分施尿素更高的番茄产量 ,但却可以明显改善番茄果实的品质。施用LP10 0处理的番茄果实干物质、蛋白质、维生素C和总糖含量以及糖酸比均显著高于单施尿素处理。DCD的施用并没有进一步提高番茄的产量和品质

Ammonium and Nitrate of Soil and Yield and Quality of Tomato as Influenced by the Application of Controlled Release Nitrogen Fertilizer

A plot experiment was conducted to study the changes of soil ammonium and nitrate,and yield and quality of tomato after application of Japanese thermoplastic resin coated urea MEISTER LP100 and LP100 plus dicyandiamide (DCD) in greenhouse. The results showed that split application of urea induced the vigorous fluctuation of soil NH 4-N, but application of LP100 could steadily keep soil NH 4-N and NO - 3-N at high levels during the first 115 days of experiment.After this period, much NH 4-N and NO - 3-N still accumulated in soil.DCD inhibited nitrification for about three months, thus increased soil NH 4-N, and diminished soil NO - 3-N,and the accumulation of NO - 3-N in the 20-40cm tillage layer of the soil. Application of LP100 didn't increase tomato yield, but improved tomato fruit qualities.Comparing with split application of urea,that of LP100 significantly increased the contents of dry mass, protein, vitamin C,and total sugar in tomato fruits. However,DCD didn't further improve tomato yield and fruit qualities.