摘要
该研究的目的是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。试验采用两因素、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。一次性施肥显著提高了玉米生育前期地下水中N浓度,加大了N的径流损失,降低了N肥利用率,使玉米生育后期供肥不足,造成玉米减产。N的主要损失载体是壤中流,平均损失量达5.08kg/ha,对环境造成了较大压力;并且受雨强影响小,受施肥方式影响大,一次性施肥显著加大了N的损失。P损失的主要载体是泥沙,受雨强影响大,雨强越大,P损失量显著增加,而受肥方式影响小。K损失的主要载体也是泥沙,平均损失量达29.1kg/ha,雨强越大,K损失量成倍增加,施肥方式对K总损失量影响不大。氮的损失载体主要是壤中流,磷钾的损失载体主要是泥沙。一次施肥显著增加了玉米生育前期壤中流N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P、K和部分N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。
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 intensity in the purple hilly area and in return to provide theoretical evidence in improving fertilizer management and nutrient loss control on sloping farmlands in purple area.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.The nitrogen content of under ground runoff was increased notably by fertilization in one time,by the way,the N loss by runoff was increased,and the nitrogen efficiency was decreased,corn yield was decreased also.The main carrier of N loss was underground runoff,the average lost amount of N was5.08 kg/ha,the lost N from field make high pressure to the environment,and N lost amount was influenced by rain intensity slightly,but was influenced by fertilization methods strongly.The main carrier of lost P was sediment,P loss was influenced by rain intensity strongly,but by fertilization methods slightly.The main carrier of lost K was sediment also,the average lost amount of K was 29.1 kg/ha,the rain intensity higher,the lost amount of K times bigger,lost amount K was influenced by fertilization methods slightly.The nitrogen content of under ground runoff was increased notably by fertilization in one time,by the way,the N loss by runoff was increased remarkablely.On the sloping purple farmland,P and K were lost in sediment 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 losses in the purple soil area,not only fertilization separately must be adopted,the integrated agronomicmethods such as cultivation practices against soil erosion and water loss,soil depth improvement and soil structure improvement can be employed also.
作者
林超文
罗春燕
庞良玉
黄晶晶
涂仕华
Lin Chaowen;Luo Chunyan;Pang Liangyu;Huang Jingjing;Tu Shihua(Soil and Fertilizer Institute,Sichuan Academy of Agricultural Sciences Chengdu 610066)
基金
作者感谢国家科技支撑计划(项目编号:2008BAD98B03和2006BAD05B06)、国际植物营养研究所、四川省科技厅应用基础项目(项目编号:2008JY0022-1)的资助。
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
