施肥对草地早熟禾草坪质量及土壤中硝态氮动态的影响

通过大田试验研究不同氮肥(缓释肥、尿素、磷酸二铵)、不同施肥次数、不同养分配施对草地早熟禾草坪质量及土壤中硝态氮动态的影响.研究发现速效肥可以迅速改变草坪颜色,缓释肥对草坪颜色的影响更为持久;施氮肥加剧了草坪夏季病害的发生,导致草坪分蘖密度下降,而施用磷酸二铵处理的草坪对褐斑病的抗性最强.整个生长季内尿素、磷酸二铵配施和4次施用缓释肥2处理草坪的均一度最好. 缓释肥的应用减小了草坪生长速率的波动;秋季2次施肥比1次施肥更有利于地下生物量的累积.土壤中0～20 cm土层硝态氮的含量受施肥影响很大,并且与不同类型肥料氮素释放模式有关.

Effects of fertilization on turf quality of Poa pratensis and nitrate dynamic in soil

A field study to compare the effects of various fertilization schemes on turf quality of Poa pratensis and nitrate dynamics in the soil was conducted in Beijing between May 2001 and November 2002. The results indicated that fast release fertilizer provided the greater initial response, while slow release fertilizer gave the outstanding residual characteristics based on color ratings. Fertilization in summer sharpened the injury of brown patch disease, whereas the least injury was observed for Diammonium-phosphate treatment. In addition, the reduced tiller number was found because of the brown patch. The turfs fertilized with slow release fertilizer at 4 applications and "Urea+Diammonium-phosphate" abtained best uniformity for the entire growing seasons. The turf fertilized with slow-release fertilizer had a slow fluctuation of growth rate. Fertilization at 2 applications in fall got more underground biomass than that at 1 application. Soil NO_3~--N concentration was mostly effected by fertilization and the NO_3~--N concentrations in soils of 0-20 cm were associated with different patterns of nutrition releasing.