摘要
【目的】揭示紫色土地区坡耕地不同施肥方式在不同雨强条件下对土壤养分流失途径及流失量的影响规律,为紫色土坡耕地肥料管理及养分流失治理提供理论依据。【方法】采用两因素、三水平随机区组试验,利用自然降雨和人工降雨相结合的方法,采用模拟径流小区观测地表径流量、壤中流量、泥沙侵蚀量,取样分析养分流失量。【结果】一次性施肥显著提高了玉米生育前期地下水中氮浓度,加大了氮的径流损失,降低了氮肥利用率,使玉米生育后期供肥不足,造成玉米减产。氮的主要损失载体是壤中流,平均损失量达5.08 kg.hm-2,对环境造成了较大压力。氮损失受雨强影响小,受施肥方式影响大,一次性施肥显著加大了氮的损失量。磷损失的主要载体是泥沙,受雨强影响大,雨强越大,磷损失量显著增加,而受肥方式影响小。钾损失的主要载体也是泥沙,平均损失量达29.1 kg.hm-2,雨强越大,钾损失量成倍增加,施肥方式对钾总损失量影响不大。【结论】氮的损失载体主要是壤中流,磷、钾的损失载体主要是泥沙。一次性施肥显著增加了玉米生育前期壤中流氮浓度,显著增加氮的损失。在紫色土地区,不仅要采用分次施肥等施肥技术控制磷、钾和部分氮损失,还需增厚土层,改良土壤结构、提高土壤蓄水保肥能力,才能更全面控制紫色土的氮、磷、钾损失。
【Objective】The purpose of this study was to investigate the influence of different fertilization methods on the pathway and amount of nutrients lost under different rain intensities in the purple hilly area and in return to provide a theoretical evidence for improving fertilizer management and nutrient loss control on sloping farmlands in purple soil area.【Method】 A completely randomized block design was employed in the experiment with three different artificial rain intensities（slight,medium and heavy）,three fertilization methods and three replications.【Result】 The nitrogen content in the underground runoff was increased notably by fertilization in one time and the amount of N lost through runoff was increased,while the maize yield and nitrogen efficiency were decreased.The main carrier of lost N was underground runoff with an average amount of 5.08 kg？hm-2.The N lost from the field put high pressure on the environment.The amount of N loss was slightly influenced by rain intensity but strongly by fertilization methods.The main carrier of P was the sediment which was closely related to rain intensity but slightly affected by fertilization methods.Similar to P,the sediment was also the main carrier of K responsible for 29.1 kg？hm-2 of soil K loss on average.The higher the rain intensity,the higher the amount of K loss,and the amount K loss was slightly affected by fertilization methods.【Conclusion】 N loss was highly correlated with runoff,especially the underground runoff in which N content was increased notably by one time fertilization.On the sloping purple farmland,P and K were mainly lost through sediments and the quantity was influenced by rain intensity,implying that to control P and K loss,soil erosion must be minimized first.In order to control N loss in the purple soil area,not only the splitting fertilization must be addressed,the integrated agronomic methods such as cultivation practices against soil erosion and water loss,soil depth improvement and soil structure improvement can be employed at the same time.
出处
《中国农业科学》
CAS
CSCD
北大核心
2011年第9期1847-1854,共8页
Scientia Agricultura Sinica
基金
国家公益性行业(农业)科研专项(20100314)
国家"十一五"科技支撑计划(2008BAD98B03和2006BAD05B06)
国际植物营养研究所
四川省科技厅应用基础项目(2008JY0022-1)
关键词
雨强
施肥方式
紫色土
养分流失
土壤侵蚀
rain intensity
fertilization method
purple soil
nutrient loss
soil erosion
