毛竹林生态系统地表径流及其氮素流失形态研究

Studies on Surface Runoff and Nitrogen Loss in Bamboo Forest Ecosystem

通过在四岭水库流域代表性毛竹林地设置定位径流小区,研究了不同施肥条件下毛竹林生态系统地表径流及其氮素流失状况。该定位试验设有对照(CK,不施肥)、农民常规高产栽培(FFP)与适地养分科学管理(SS-NM)共3个施肥处理。结果表明,在2009年6-12月的观察期内,各处理(CK、SSNM、FFP)在各次自然降雨条件下产生的径流总量分别达到279,284,267m3/hm2,泥沙流失总量分别达到393,369,396kg/hm2,全氮流失量分别为0.87,0.92,0.82kg/hm2。径流量、泥沙流失量和全氮流失量都与降雨量之间呈极显著正相关。径流量的产生主要集中在8月份,泥沙流失量主要集中在6,7,8三个月。土壤氮素流失的主要形态是颗粒氮(PN)和水溶性总氮(DN),分别占全氮流失量的51%和49%。CK、SSNM、FFP处理在此期间的径流可溶性氮(DN)流失量分别为0.37,0.46,0.49kg/hm2。与农民常规施肥措施相比,适地养分科学管理(SSNM),不仅可以明显减少毛竹林地泥沙的流失量,而且可以减少径流可溶性氮的流失量。

Through setting runoff fields in typical bamboo （Phylostachys pubescens） forests to investigate the effect of different fertilization treatments on runoff and nutrient losses under field conditions.The results showed that in the period from June to December of 2009,under the treatments of control （CK）,site-specific nutrient management （SSNM）,and farmers’ fertilizer practice （FFP）,the runoff loss reached 279,284,267 m^3/hm^2,the soil particle loss reached 393,369,396 kg/hm2,respectively.The runoff and soil particle losses had close correlations with the precipitation of the period.Largest losses happened in August for runoff and in June,July and August for soil particles.The losses of particle nitrogen （PN） and water-soluble nitrogen （DN） are about 51% and 49% of the total N losses,respectively.The loss of water-soluble N in the period reached 0.37,0.46,0.49 kg/hm2 for CK,SSNM and FFP,respectively.The main factor influencing soil N loss is precipitation.Comparing with FFP,the SSNM treatment significantly reduced soil particle loss and water-soluble N loss as well in this experiment.