不同耕作方式对黄土高原黑垆土有机碳库组成的影响  

Effects of Different Tillage Methods on Soil Organic Carbon Pool Composition in Dark Loessial Soil on Loess Plateau

作　　者：王旭东[1] 张霞[1] 王彦丽 李军[2] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]西北农林科技大学农学院,陕西杨凌712100

出　　处：《农业机械学报》2017年第11期229-237,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：农业部公益性行业科研专项(201503116)

摘　　要：以黄土高原黑垆土8年(2008—2015年)的不同耕作定位试验为对象,研究了在秸秆还田条件下3种连年单一耕作(翻耕(CC)、免耕(NN)、深松(SS))和3种轮耕措施(免耕-深松(NS)、深松-翻耕(SC)、翻耕-免耕(CN))对农田土壤有机碳库、玉米产量和秸秆还田后表观腐殖化系数的影响。结果表明:与翻耕相比,深松、免耕和轮耕措施主要增加了0~10 cm表层土壤有机碳(SOC)、微生物量碳(MBC)、水溶性碳(WSOC)的含量和储量,且提高了MBC/SOC和WSOC/SOC质量比。在0~10 cm表层土壤中,各耕作处理间难氧化有机碳(HOC)含量无明显差异,但深松、免耕和轮耕措施分别增加了10~20 cm、35~50 cm和20~35 cm土层的HOC/SOC质量比;免耕处理显著增加了0~50 cm土层的HOC总储量。与翻耕处理相比,深松、免耕和轮耕处理提高了玉米产量和玉米秸秆量,其中NS处理增加幅度最大,分别达到13.79%(籽粒)和12.04%(秸秆);进行8年玉米秸秆还田,在翻耕措施下其表观腐殖化系数为8.94%,免耕、深松和轮耕措施提高了还田玉米秸秆的表观腐殖化系数,其中NS处理达到14.09%,显著高于翻耕处理。从土壤碳库和玉米产量角度考虑,免耕与深松相结合的轮耕措施是适合当地土壤条件的耕作模式。To investigate the effect of different tillage methods on soil organic carbon pool,straw returning apparent humification coefficient and maize yield,an eight-year（ 2008—2015） field experiment with six tillage measures under straw returning in dark loessial soil on Loess Plateau was conducted. The tillage measures included three single continuous tillages（ no-tillage（ NN）,subsoiling（ SS） and conventional tillage（ CC））, and three rotational tillages（ no-tillage-subsoiling（ NS）, subsoilingconventional tillage（ SC） and conventional tillage-no-tillage（ CN））. The results showed that compared with the conventional tillage,the measures of NN,SS and rotational tillage increased the content of soil organic carbon（ SOC）,microbial biomass carbon（ MBC）,water-soluble organic carbon（ WSOC） in0 ~ 10 cm soil layer,improved the ratios of MBC to SOC and WSOC to SOC. Although there was no significant difference in the hardly oxidized carbon（ HOC） content for different treatments in 0 ~ 10 cm soil layer,the ratio of HOC to SOC was increased by SS,NN and rotational tillage in the soil layer of10 ~ 20 cm,35 ~ 50 cm and 20 ~ 35 cm,respectively. The store of HOC was increased significantly in the NN treatment in 0 ~ 50 cm soil layer. Compared with conventional tillage,the yield of corn and the dry mass of corn straw were increased in the treatments of SS,NN and rotational tillage,the maximum increment was found to be in the treatment of NS,by 13. 79% for grain yield and 12. 04% for straw dry mass,respectively. After eight-year straw returning,the apparent humification coefficient of straw in conventional tillage treatment was 8. 94%,which was lower than those in the treatments of NN,SS and rotational tillage. The apparent humification coefficient of returning straw was 14. 09% in the NS treatment,which was the highest among all the treatments. Based on soil carbon pool and corn yield,the tillage of NS was the most suitable measure for the local soil conditions.

关 键 词：黑垆土 耕作方式 有机碳库构成 表观腐殖化系数 

分 类 号：S153.6[农业科学—土壤学]