西南丘陵区不同耕作模式下玉米田土壤呼吸及影响因素分析

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 西南丘陵区不同耕作模式下玉米田土壤呼吸及影响因素 DOI: 10.5846/stxb201302010211 作者: 作者单位: 西南大学农学与生物科技学院,西南大学农学与生物科技学院,西南大学农学与生物科技学院,西南大学农学与生物科技学院,西南大学农学与生物科技学院,西南大学农学与生物科技学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(31271673); 国家自然科学基金项目(30871474); 重庆市科技攻关项目(CSTC,2008AB1001) Analysis of soil respiration and influencing factors in maize farmland under different tillage patterns in hilly area in Southwest China Author: Affiliation: College of Agronomy and Biotechnology,Engineering Research Center of South Upland Agriculture,Ministry of Education,College of Agronomy and Biotechnology,Engineering Research Center of South Upland Agriculture,Ministry of Education,College of Agronomy and Biotechnology,Engineering Research Center of South Upland Agriculture,Ministry of Education,College of Agronomy and Biotechnology,Engineering Research Center of South Upland Agriculture,Ministry of Education,College of Agronomy and Biotechnology,Engineering Research Center of South Upland Agriculture,Ministry of Education,College of Agronomy and Biotechnology,Engineering Research Center of South Upland Agriculture,Ministry of Education Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:为了探讨不同耕作模式对旱作农田土壤呼吸的影响,采用LI6400-09在重庆北碚西南大学实验农场对平作(T)、垄作(R)、平作+覆盖(TS)、垄作+覆盖(RS)、平作+覆盖+秸秆速腐剂(TSD)、垄作+覆盖+秸秆速腐剂(RSD)6种处理下的西南紫色土丘陵区小麦/玉米/大豆套作体系中玉米生长季节的土壤呼吸及其水热生物因子进行了测定和分析.结果表明,玉米整个生育期阶段农田土壤呼吸先增强后减弱,变化范围为1.011-5.575 μmol m-2 s-1,不同处理土壤呼吸速率差异显著,表现为RSD > TSD > TS > RS > T > R.垄作降低了玉米农田土壤呼吸速率,秸秆覆盖提高土壤呼吸速率.10 cm土层的土壤温度表现为R>T>RSD>TSD>RS>TS,土壤呼吸的土温敏感指标Q10值排序为TS > TSD > RS=R > T > RSD.5 cm土层的土壤含水量高低排序为TSD > TS > RS > RSD > R > T.土壤呼吸的土壤水分响应阈值大小排序依次为R < T < RS < RSD < TS < TSD,介于11.98%-13.11%.其中垄作下的响应阈值较低,秸秆覆盖的作用提高了土壤水分的响应阈值.干漏斗法捕获的土壤动物在玉米农田生态系统中优势类群有弹尾目、螨目和双翅目.单纯的垄作减少了土壤动物数量,秸秆覆盖下土壤动物数量明显增多,土壤动物多样性指数较高;陷阱法捕获的土壤动物与土壤呼吸存在正相关关系,地表活动的土壤动物越多,土壤呼吸作用就越强,其中R的相关系数最高,r=1.000,P=0.017,TS的相关系数r=0.915,P=0.029,而传统耕作下土壤动物数量与土壤呼吸没有明显的关系.玉米田整个生长季均表现为碳汇,净碳汇为679.244-723.764 g(C)/m2.与对照相比,垄作和秸秆覆盖有利于农田生态系统的碳汇,增汇达2.91%-6.55%. Abstract:In order to investigate the effects of different tillage patterns on soil respiration in dry cropping farmland in purple hilly region in southwest China, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Beibei District of Chongqing. The soil respiration rate and the soil hydrothermal and biotic factors were measured during the growth period of maize in the triple intercropping system of wheat/maize/soybean. There were six treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching), RS (ridge tillage + straw mulching), TSD (traditional tillage + straw mulching + decomposing inoculants), and RSD (ridge tillage + straw mulching + decomposing inoculants), which were replicated for three times. The results indicated that the soil respiration rate was firstly increased and then decreased during the whole growth period of maize, with the variation range of 1.011-5.575 μmol m-2 s-1. There were significant differences of soil respiration rate among different treatments, which could be ranked as RSD > TSD > TS > RS > T > R. Ridge tillage reduced soil respiration in maize farmland, whereas straw mulching treatment was opposite. The treatment of straw mulching added with decomposing inoculants resulted in the highest soil respiration rate because of the high activity of microbial. The soil temperature in 10 cm layer was ranked as R > T > RSD > TSD > RS > TS. It was higher under ridge tillage than under straw mulching, while that under the treatment of straw mulching added with decomposing inoculants was in between the two above. The sensitive indicator of soil temperature (Q10) was ranked as TS > TSD > RS=R > T > RSD. Ridge tillage and straw mulching treatments enhanced the sensitivity of soil temperature, but the influence of adding decomposing inoculants was uncertain. A high Q10 meant that the decrease of soil temperature would lead to a big reduction in soil respiration. The straw mulching treatment could lower soil temperature and thus helped to reduce emissions of carbon dioxide. The soil moisture in 5 cm layer was ranked as TSD > TS > RS > RSD > R > T. The response threshold of soil moisture was sorted as R < T < RS < RSD < TS < TSD, which varied within 11.98%-13.11%. The response threshold was improved by straw mulching but it was relatively low under ridge tillage. In a sense, under the condition of certain soil moisture, the soil respiration would be inhibited prematurely under ridge tillage. The dominant groups of soil animals in maize field were Collembola, Acarina and Diptera. Compared to the control, ridge tillage reduced the number of soil animals, but straw mulching increased it and improved the index of soil animal diversity. This indicated that soil tillage patterns had great impact on soil animals. Soil respiration was only related with the animals above soil surface. The more was the amount of animals being active above soil surface, the stronger was the soil respiration. In all the treatments, the correlation coefficient of R was the highest (r=1.000, P=0.017), followed by TS (r=0.915, P=0.029). However there was no remarkable relationship between soil animals and soil respiration under traditional tillage. The farmland system showed a carbon sequestration during the whole growth period of maize and the net carbon sink was 679.244-723.764 g(C)/m2. Compared with the control, ridge tillage and straw mulching treatments increased carbon sequestration by as much as 2.91%-6.55%. It was concluded that conservation tillage paterns of ridge planting and straw mulching could improve the carbon sink in maize farmland ecosystem. 参考文献 相似文献 引证文献