长期施肥旱地土壤易分解与耐分解氮的矿化特性  

Mineralization Characteristics of Upland Soil Labile and Recalcitrant Nitrogen Under Long-Term Different Fertilization Systems

作　　者：武红亮 于维水 朱平[2] 张水清[3] 赵雅雯[1] 刘婧[1] 王士超[1] 孟繁华 卢昌艾[1] 

机构地区：[1]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 [2]吉林省农业科学院农业资源与环境研究所,长春130124 [3]河南省农业科学院植物营养与资源环境研究所,郑州450002 [4]河南省土壤肥料工作站,郑州450002

出　　处：《中国农业科学》2015年第23期4698-4706,共9页Scientia Agricultura Sinica

基　　金：国家科技支撑计划(2012BAD05B05);国家"973"计划(2013CB127404);国家公益性行业(农业)科研专项(201203030)

摘　　要：【目的】土壤易分解氮库和耐分解氮库是土壤有机质的重要组分,其矿化能力的大小可反映土壤有机氮的周转性能。论文旨在研究长期不同施肥制度下土壤易分解氮库与耐分解氮库的矿化特性,为了解不同培肥措施及其氮素供应提供依据。【方法】以中国长期不同施肥处理的2种旱地土壤(黑土和潮土)为例,选取不施肥(CK)、单施化肥(NPK)、化肥配施秸秆(NPKS)和化肥配施有机肥(NPKM)4个处理,采用颗粒密度法,将土壤有机氮分为易分解氮和耐分解氮2个组分,室内培养分析不同组分氮的矿化特性。【结果】筛分及培养结果显示,黑土和潮土的平均质量回收率和氮回收率均超过97%,易分解和耐分解氮组分矿化量之和占原土矿化量的平均比例为99.91%(99.89%—99.93%),是一种研究土壤易分解和耐分解氮组分矿化特性的可行方法。2种旱地土壤NPK、NPKS和NPKM处理易分解氮组分净氮矿化潜势(除黑土NPK处理差异不显著)较CK处理显著提高26.82%—137.10%;不同施肥处理对旱地黑土、潮土易分解氮组分净氮矿化潜势影响显著,其中,黑土NPKM处理易分解氮组分净氮矿化潜势为1.48 mg·kg-1·d-1,显著优于NPKS(1.02 mg·kg-1·d-1)与NPK(0.75 mg·kg-1·d-1)处理;潮土NPKM处理易分解氮组分净氮矿化潜势为1.17 mg·kg-1·d-1,显著优于NPKS(0.89 mg·kg-1·d-1)与NPK(0.76mg·kg-1·d-1)处理;旱地土壤各处理耐分解氮组分净氮矿化潜势之间差异不显著,其中,黑土各处理耐分解氮组分平均净氮矿化潜势为0.58 mg·kg-1·d-1(0.52—0.63 mg·kg-1·d-1),潮土为0.51 mg·kg-1·d-1(0.40—0.62 mg·kg-1·d-1)。不同施肥处理旱地黑土、潮土易分解氮组分净氮矿化潜势均显著大于同处理耐分解氮组分净氮矿化潜势,NPKM处理两者显现出最大差异,其中,黑土易分解氮组分净氮矿化潜势是同处理(按CK、NPK、NPKS、NPKM顺序)耐分解氮组分的1.41、1.39、1.75和2.35倍,潮土易分�【Objective】Labile nitrogen（Lab-N） and recalcitrant nitrogen（Rec-N） are important components of soil organic matter, and their mineralization ability has an effect on organic nitrogen turnover properties. The objective of this study is to research the mineralization characteristics of soil labile and recalcitrant nitrogen under different long-term fertilization, and to provide a basis for different fertilization measures and their nitrogen supplying capacities. 【Method】Using laboratory incubation method, soil labile and recalcitrant nitrogen fractions separated by particle size-density separation method were studied under four treatments, namely no fertilizer（CK）, chemical fertilizer（NPK）, chemical fertilizer combined with straw（NPKS）, and chemical fertilizer combined with manure（NPKM） from two typical long-term experiment sites（black soil and fluvo-aquic soil） in China. 【Result】Results of laboratory sieving and incubation showed that the method was simple and suitable to study the mineralization characteristics of soil labile and recalcitrant nitrogen fractions in which average soil mass recovery and average soil nitrogen recovery were both above 97%, and average mineralization contribution rate（soil labile and recalcitrant nitrogen fractions mineralization amount to that oforiginal soil） was 99.91%（99.89%-99.93%）. Net-nitrogen（Net-N） mineralization potential of soil labile nitrogen under treatments of NPK, NPKS and NPKM were higher than that under CK treatments by 26.82%-137.10%（except NPK of black soil）. Different fertilizer treatments had a significant influence on Net-N mineralization potential of soil labile nitrogen in black soil and fluvo-aquic soil. The Net-N mineralization potential of soil labile nitrogen in black soil under NPKM treatment was 1.48 mg·kg-1·d-1, which was higher compared with NPKS（1.02 mg·kg-1·d-1） and NPK（0.75 mg·kg-1·d-1）. The Net-N mineralization potential of soil labile nitrogen in fluvo-aquic soil under NPKM treat

关 键 词：易分解氮 耐分解氮 黑土 潮土 矿化特性 长期施肥 

分 类 号：S158[农业科学—土壤学]