红壤酸化及石灰改良影响冬小麦根际土壤钾的有效性  

The response of soil potassium availability in rhizospheric soil of winter wheat to acidified and limed red soil

作　　者：梅旭阳 高菊生[2,3] 杨学云[1] 黄晶[2,3] 蔡泽江[2,3] 李冬初[2,3] 王伯仁[2,3] 柳开楼[2,4] 徐明岗[2,3] 张会民[2,3] 

机构地区：[1]西北农林科技大学资源环境学院,农业部西北植物营养与农业环境重点实验室,陕西杨凌712100 [2]中国农业科学院农业资源与农业区划研究所,耕地培育技术国家工程实验室,北京100081 [3]中国农业科学院农业资源与农业区划研究所,祁阳农田生态系统国家野外科学观测研究站,湖南祁阳426182 [4]江西省红壤研究所,国家改良工程技术研究中心,江西进贤331717

出　　处：《植物营养与肥料学报》2016年第6期1568-1577,共10页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金(41371293,41671301);国家“973”计划(2011CB100501);国家公益性行业(农业)科研专项(201203030)资助

摘　　要：【目的】了解初始酸度对石灰改良红壤钾素有效性的效应,为酸化红壤改良提供依据和支撑。【方法】利用湖南祁阳典型的第四纪红土,制备p H分别为4.0、4.5、4.8、5.2的土壤。每个酸度土壤的一半加石灰改良至p H 6.0(石灰改良处理),另一半不变(酸化对照),以该土壤进行了小麦盆栽试验。每盆内放入一个尼龙网根袋,袋内添加供试红壤150 g,其余放置袋外,共1.65 kg。小麦生长80天后收获,调查了小麦生物量和钾吸收量,测定比较了小麦根际和非根际土壤不同形态的钾含量变化。【结果】1)冬小麦生物量(地上部和根部)与供试土壤初始p H显著正相关(P<0.05),也与钾吸收量显著正相关(P<0.05)。石灰改良处理冬小麦生物量均显著高于相应的酸化对照,并随供试土壤初始p H升高而显著升高。2)不同酸化土壤冬小麦根际土壤速效钾含量均随p H升高显著降低,非根际土壤的速效钾含量显著高于相应的根际土壤(除p H 4.0外)。石灰改良处理根际土壤速效钾含量均显著低于相应的酸化对照,且非根际土壤显著高于根际土,非根际土壤速效钾含量随初始p H升高而显著下降。3)不同酸化土壤冬小麦根际土壤钾离子饱和度随p H升高而显著下降,非根际土壤钾离子饱和度则随p H升高呈增加趋势。石灰改良处理土壤各处理根际土钾离子饱和度均显著低于非根际土,非根际土钾离子饱和度与酸化对照的变化趋势一致。4)不同酸化处理红壤冬小麦生物量与根际速效钾亏缺量呈极显著正相关(P<0.01),冬小麦根际土壤速效钾亏缺率和冬小麦吸钾量、根际钾离子饱和度亏缺率均呈极显著正相关(P<0.01);而石灰改良处理根际土壤速效钾亏缺率则与初始p H呈显著负相关(P<0.05)。【结论】在本试验的p H范围内,酸化条件下,根际土壤速效钾含量随p H降低而升高,而冬小麦吸钾量及生物量均随p H升高而升高。表明�【Objectives】Understanding the effect of soil initial acidity on the potassium availability will provide basis to remediate acidified soil.【Methods】A typical quaternary red clay soil in Qiyang County, Hunan Province, was acidified into soil pH gradient of 4.0, 4.5, 4.8 and 5.2（refer to acidified）. For each pH gradient,half of the soil was added with lime to regulate the pH to a final value of 6（refer to limed）. A winter wheat pot experiment was then conducted using the treated soils. A nylon root bag was placed inside each pot, 150 g soil was placed inside the nylon root bag and total 1.65 kg of the treated red soil was add into the pot. Wheat biomass and potassium uptake were investigated after 80 days＇ growth of winter wheat, and the changes of potassium content in different forms of rhizospheric and bulk soils of winter wheat were measured and compared.【Results】1） The biomass of winter wheat（roots and shoots） was significantly higher in all the limed treatments than in the corresponding acidified treatments; The biomass was positively and significantly（P〈0.05） correlated to the soil initial pH value for both acidified and limed soils, but it was only positively and significantly（P〈0.05）correlated to the potassium uptake for acidified treatments. 2） The concentration of soil available potassium was markedly higher in bulk soils than those in corresponding rhizospheric soils for both sets of soils except for acidified soil of pH 4.0 where the same value was observed; soil available potassium in rhizospheric soils of acidified treatment and in bulk soils of limed declined with increasing initial soil pH value. 3） Soil potassium ion saturation was significantly higher in bulk soils than in corresponding rhizospheric soils for both sets of the soils;Soil potassium ion saturation in rhizospheric soils of acidified treatment declined with increasing soil pH value;whereas it showed an increasing trend in bulk soils of both acidified and limed treatments. 4） The winter wheat

关 键 词：红壤 酸化 根际土 石灰 钾有效性 

分 类 号：S156.6[农业科学—土壤学] S158[农业科学—农业基础科学]