有机肥替代化学氮肥对黄壤活性有机碳组分、酶活性及作物产量的影响

Effects of Replacing Chemical Nitrogen Fertilizer with Organic Fertilizer on Active Organic Carbon Fractions,Enzyme Activities,and Crop Yield in Yellow Soil

以贵州典型黄壤为研究对象,设置不施肥(CK)、单施化肥(NP)、50%有机肥替代化学氮肥[1/2(NPM)]和100%有机肥替代化学氮肥(M)这4个处理进行田间试验,研究有机肥替代化学氮肥对黄壤有机碳及其活性组分、土壤碳库管理指数、土壤酶活性及玉米大豆产量的影响,可为该地区科学施肥和土壤质量提升提供理论依据.结果表明,有机肥替代化学氮肥显著提高土壤p H、有机碳(SOC)、全氮(TN)含量和C/N.与CK和NP处理比,有机肥替代化学氮肥对土壤活性有机碳组分含量及其分配比例和土壤碳库管理指数(CPMI)均有提升效果,且均以50%有机肥替代化学氮肥提升效果最佳.与NP处理相比,1/2(NPM)处理显著增加了土壤易氧化有机碳(ROC_(333)和ROC_(167))、可溶性有机碳(DOC)和微生物生物量碳(MBC)含量,其增幅依次为22.90%、8.10%、29.32%和23.22%.相对于CK和NP处理,有机肥替代化学氮肥均提高了土壤酶活性,1/2(NPM)处理的土壤过氧化氢酶、脲酶、蔗糖酶和磷酸酶活性较NP处理分别显著提高了21.89%、8.24%、34.91%和18.78%;各施肥处理均显著提高了玉米大豆产量,与NP处理相比,1/2(NPM)和M处理的玉米产量分别显著提高了44.15%和17.39%,大豆产量在各施肥处理之间无显著性差异.相关性分析表明,土壤SOC与ROC_(333)、ROC_(167)、ROC33、DOC和MBC以及各土壤活性有机碳组分之间呈显著正相关,CPMI与土壤SOC及其活性组分之间呈极显著正相关关系(P<0.01).玉米产量与土壤酶活性、CPMI、土壤SOC及其活性组分均呈显著正相关关系(P<0.05).因此,从增产和土壤培肥角度看,50%有机肥替代化学氮肥有利于改善土壤质量,提高土壤肥力,是贵州安顺黄壤地区实现作物高产的关键施肥技术.

Taking the typical yellow soil in Guizhou as the research object,four treatments were set up:no fertilization(CK),single application of chemical fertilizer(NP),50%organic fertilizer instead of chemical nitrogen fertilizer[1/2(NPM)],and 100%organic fertilizer instead of chemical nitrogen fertilizer(M).The effects of organic fertilizer instead of chemical nitrogen fertilizer on organic carbon and its active components,soil carbon pool management index,soil enzyme activity,and maize and soybean yield in yellow soil were studied in order to provide theoretical basis for scientific fertilization and soil quality improvement in this area.The results showed that the replacement of chemical nitrogen fertilizer by organic fertilizer significantly increased soil pH,organic carbon(SOC),total nitrogen(TN)content,and C/N ratio.Compared with those in the CK and NP treatments,the content and distribution ratio of soil active organic carbon components and soil carbon pool management index(CPMI)were improved by replacing chemical nitrogen fertilizer with organic fertilizer,and the effect of replacing chemical nitrogen fertilizer with 50%organic fertilizer was the best.Compared with those in the NP treatment,the 1/2(NPM)treatment significantly increased the contents of soil readily oxidizable organic carbon(ROC_(333),ROC_(167)),dissolved organic carbon(DOC),and microbial biomass carbon(MBC)by 22.90%,8.10%,29.32%,and 23.22%,respectively.Compared with those under the CK and NP treatments,organic fertilizer instead of chemical nitrogen fertilizer increased soil enzyme activities.The activities of catalase,urease,sucrase,and phosphatase in the 1/2(NPM)treatment were significantly increased by 21.89%,8.24%,34.91%,and 18.78%,respectively,compared with those in the NP treatment.Compared with that of the NP treatment,the maize yield of the 1/2(NPM)and M treatments was significantly increased by 44.15%and 17.39%,respectively.There was no significant difference in soybean yield among different fertilization treatments.Correlation analysis showed that soil SOC was significantly positively correlated with ROC_(333),ROC_(167),ROC33,DOC,MBC,and soil active organic carbon components,and CPMI was significantly positively correlated with soil organic carbon and its active components(P<0.01).Corn yield was significantly positively correlated with soil enzyme activity,CPMI,total organic carbon,and its active components(P<0.05).Therefore,from the perspective of yield increase and soil fertility,50%organic fertilizer instead of chemical nitrogen fertilizer was conducive to improving soil quality and soil fertility,which is the key fertilization technology to achieve a high yield of crops in the yellow soil area of Anshun,Guizhou.