摘要
【目的】长期过量施用化学氮肥加剧了红壤区农田土壤酸化,严重制约着该区域农业的可持续发展。施用石灰和有机肥是防治红壤酸化的主要措施,我们研究了有机无机肥配合提高红壤抗酸化能力的作用与机理。【方法】本研究基于2009年在湖南祁阳中国农业科学院红壤站开展的有机肥替代化学氮肥长期定位试验,其中4个处理分别为单施化肥(由于酸化严重,于2018年底添加石灰改良)、有机肥替代化肥氮20%、40%和60%,供试有机肥为猪粪。采集2018和2020年的土壤样品,分析各施肥处理红壤pH、交换性酸铝、阳离子交换量、有机质、酸缓冲能力等指标的变化及相互关系。【结果】至2018年,单施化肥处理较试验之初土壤pH降低了0.48个单位,交换性酸、铝分别增加了2.74和1.06 cmol/kg;添加石灰改良后,土壤pH升高了0.58个单位,交换性酸、铝分别降低了2.62和1.45 cmol/kg。有机肥替代化肥氮40%和60%处理均可有效防治红壤酸化,其中以替代60%处理效果最佳;至2020年60%有机替代处理土壤pH较初始值提高了0.78个单位,交换性酸和交换性铝分别降低了1.10和1.25 cmol/kg。有机肥替代化肥氮40%和60%处理较单施化肥处理显著提高了土壤阳离子交换量,而石灰改良前后土壤阳离子交换量无显著变化。土壤酸缓冲曲线表明,土壤交换性铝含量随着pH的降低而显著升高,单施化肥、有机肥替代化肥氮20%、40%和60%处理的斜率分别为2.71、2.42、1.93和0.16;土壤交换性铝对pH响应斜率与土壤pH、交换性镁、阳离子交换量、交换性钾、有机质含量呈极显著或显著负相关关系。【结论】有机肥替代40%以上化学氮肥既能防治红壤酸化,又能提升红壤抗酸化能力。土壤阳离子交换量和有机质可能是导致土壤交换性铝对pH响应差异的主要因素,即阳离子交换量和有机质含量高的土壤pH降低1个单位时,交换性铝增幅较小,�
【Objectives】Red soil acidification has intensified due to the overuse of chemical N fertilizers;liming and manuring are two main methods of preventing red soil acidification.However,there is a limited understanding of how manure impacts the acid resistance of red soils.【Methods】An 11-year field experiment started in 2009 in Qiyang Experimental Station,Hunan Province.Here,we tested red soil in a double rice planting system.The four treatments were 100%chemical fertilizer control(with lime application in 2018 to neutralize severe soil acidity)and an organic fertilizer ratio of 20%,40%,and 60%of the total N input.The organic fertlizer used in this experiment was swine manure.After harvesting rice in 2018 and 2020,soil samples were collected for pH,exchangeable acidity,cation exchange capacity,organic matter,and acid buffer capacity.【Results】CK decreased soil pH by 0.48 units and increased exchangeable acidity and aluminum by 2.74 and 1.06 cmol/kg by2018(P<0.05),compared to the initial soil.The liming in 2018 increased soil pH by 0.58 units and decreased the exchangeable acidity and aluminum by 2.62 and 1.45 cmol/kg,respectively.Replacing 40%and 60%of the total N with swine manure controlled soil acidification effectively.By 2020,the 60%manure treatment increased the soil pH by 0.78 units and decreased the exchangeable acidity and Al by 1.10 and 1.25 cmol/kg,respectively,as compared with the initial value in 2009.Soil exchangeable acidity was positively correlated with exchangeable Al and the slopes and negatively correlated with pH and exchangeable Ca(P<0.05);the slopes of soil exchangeable Al to pH had a(P<0.05)negative correlation with soil pH,exchangeable Mg and cation exchange capacity,exchangeable K and organic matter.【Conclusions】In conclusion,replacing more than 40%of the total N source with swine manure could effectively prevent red soil acidification.Soil cation exchange capacity and organic matter are two main drivers of soil exchangeable Al response to pH among treatments.This implies that
作者
胡天睿
蔡泽江
王伯仁
张璐
文石林
朱建强
徐明岗
HU Tian-rui;CAI Ze-jiang;WANG Bo-ren;ZHANG Lu;WEN Shi-lin;ZHU Jian-qiang;XU Ming-gang(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/Qiyang Farmland Ecosystem National Observation and Research Station,Beijing 100081,China;College of Agriculture,Yangtze University,Jingzhou,Hubei 434025,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2022年第11期2052-2059,共8页
Journal of Plant Nutrition and Fertilizers
基金
国家自然科学基金项目(41977104,U19A2046)。
关键词
红壤旱地
长期施肥
土壤酸碱缓冲性能
土壤交换性铝
阳离子交换量
upland red soil
long-term fertilization
soil acid-base buffer performance
soil exchangeable aluminum
cation exchange capacity
