速效氮肥和缓释肥配施对高羊茅草坪质量及土壤硝态氮动态的影响

为了研究氮肥对草坪观赏质量及草坪土壤的影响，本试验分析了速效氮肥和缓释氮肥的不同配比对高羊茅（Festuca arundinacea）草坪质量及土壤硝态氮分布的影响。试验设六个处理：普通尿素与包膜尿素比例为7∶3（A），6∶4（B），5∶5（C），4∶6（D），3∶7（E），及对照为不施肥（CK）。结果表明，当速效氮肥和缓释氮肥配施比例为3∶7时，草坪生长速率稳定，地上生物量增长均匀，分蘖数增加快，地下生物量增长大，草坪的观赏质量高。当高羊茅休眠时，各处理0～60 cm土层硝态氮积累量占0～100 cm土壤剖面积累总量的百分比为48%～60%，硝态氮的淋溶风险顺序为A > C > B > D > CK > E。综合分析速效氮肥和缓释氮肥配施比例对高羊茅观赏质量和土壤硝态氮时空分布下的环境风险，合理的配施比例应控制在3∶7左右。

Effects of Combined Application of Both Fast-release Fertilizer and Slow-release Fertilizer on Festuca arundinacea Growth and Nitrate Nitrogen Dynamic in Soil

In order to study the effects of nitrogen fertilizer on turfgrass quality and soil,this trial analyzed the effects of different proportions of fast-release fertilizer and slow-release fertilizer application on the quality of grass and the nitrate nitrogen (NO₃^--N) on the field of tall fescue (Festuca arundinacea). The trial was designed with six treatments:the ratios of common urea (U) and coated urea (S) were 7:3 (A),6:4 (B),5:5 (C),4:4 (D),3:7 (E),and the control (no fertilization,CK). The results showed that when the ratio of fast-release fertilizer and slow-release fertilizer was 3:7,the grass growth rate of lawn was stable,the aboveground biomass increased more uniformly,the number of tillers increased more quickly,the underground biomass increased more greatly,and the quality of grass was the highest. When tall fescue was dormant,the accumulation of NO₃^--N in 0~60 cm soil layers was 48% to 60% of those in 0~100 cm soil layers. The risk of leaching was A > C > B > D > CK > E. Based on a comprehensive analysis of fast-release fertilizer and slow-release fertilizer application on the visual quality of Festuca arundinacea and the environment risk of soil NO₃^--N leaching,the reasonable proportion should be at about 3:7.