长期施用化肥和稻草对红壤性水稻土钾素固定的影响  

Effects of Long-term Application of Fertilizer and Rice Straw on Potassium Fixation of Reddish Paddy Soil

作　　者：廖育林[1,2,3] 郑圣先[1,3] 鲁艳红[1,2,3] 杨曾平[1,2,3] 聂军[1,3] 谢坚[1,3] 

机构地区：[1]湖南省土壤肥料研究所,长沙410125 [2]湖南农业大学资源与环境学院,长沙410128 [3]农业部望城红壤水稻土生态环境蘑点野外科学观测实验站,湖南长沙410125

出　　处：《水土保持学报》2011年第1期70-73,95,共5页Journal of Soil and Water Conservation

基　　金：国家“十一五”科技支撑计划项目(2006BAD05B09);国际植物营养研究所(IPNI)资助项目(Hunan-14);湖南省农业科学院科技创新项目(2009hnnkycx23)

摘　　要：研究了长期定位施肥试验中连续27年(1981-2007年)施用化肥和稻草对红壤水稻土钾素固定及其影响因素的影响。本试验选择了其中5个处理:CK(不施肥)、NP(施氮、磷肥)、NPK(施氮、磷、钾肥)、NP+RS(施氮、磷肥和稻草)和NPK+RS(施氮、磷、钾肥和稻草)。结果表明,在加入外源钾浓度0.4～4.0g/L的范围内,土壤固钾量均随着加入外源钾浓度的增加而增大。5个施肥处理的固钾能力存在差异,与试前土壤相比,长期不施钾(CK和NP)处理土壤的固钾能力增强,长期施钾肥或稻草(NPK、NP+RS和NPK+RS)处理土壤的固钾能力降低,长期施用钾肥和稻草是影响土壤固钾能力的重要原因,施钾量高的处理土壤的固钾能力低。在高强度稻-稻种植条件下,水稻作物从土壤中带走大量的钾。长期不施用钾肥,会导致土壤钾素的严重耗竭,此后施入的钾则会被土壤固定,导致钾肥对当季作物的有效性降低。当土壤中钾含量相对较高时,施入钾肥则不易被吸附固定。如果施入的钾不能及时被作物吸收利用,则极易被淋失。长期施用钾肥和稻草后,土壤速效钾和缓效钾含量增加,土壤的固钾能力降低;另外,长期施用钾肥和稻草引起土壤K+饱和度的增加,也使土壤的固钾能力降低。A 27 years of long-term experiment was conducted to evaluate the effects of fertilizer and rice straw application on potassium fixation changes and the factors affecting K fixation in reddish paddy soil.There were 5 treatments,namely,CK（without fertilization）,NP（N,P fertilizers）,NPK（N,P and K fertilizers）,NP＋RS（NP plus rice straw） and NPK＋RS（NPK plus rice straw） in this study.The results showed when added K ranging from 0.4 g/L to 4.0 g/L,the rate of K fixation increased with K addition after 54 season rice cropping over 27 years period.The values of K fixation capacity were different among five treatments.The K fixation value in the treatments with no application K treatments（CK and NP） was increased compared with initial soil value,while K fixation value in treatments with K application and rice straw application（NPK,NP＋RS and NPK＋RS） were decreased compared with initial soil value.The results indicated that the mail reason why affecting the increase of K fixation capacity was due to the long-term application of K fertilizer and rice straw,but the capacity of K fixation was relatively lower when application rate K fertilizer was higher.The long-term application of K fertilizer would be lead to K depletion of soil potassium,because a large amount of K was removed by rice crop from the soil under highly intensity rice-rice planting system.A long-term no application of K fertilizer would result in severe K depletion in soil,after that,K was applied into soil,a large amount of K was fixed by the soil,and reduced efficiency of K for crops in season.When the K was relatively higher in soil,it was not easily adsorbed and fixed by the soil.If the K can not be absorbed and utilized by crop in time,it was very likely to leach.After long-term application of K fertilizer and rice straw,the content of available K and slowly available K in soil was increased,and K fixation capacity was decreased.In addition,increasing K＋ saturation could also result in reduction of soil K fixation capaci

关 键 词：化肥 稻草 红壤水稻土 钾素固定 

分 类 号：S153.6[农业科学—土壤学]