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以2001年在东北典型黑土上进行的保护性耕作长期定位试验下免耕、垄作及常规耕作土壤进行了室内培养实验,按照田间持水量(water-holding capacity,WHC)的30%、60%、90%、120%、150%、180%、210%、240%、270%设定了9个水分梯度,并分别对其二氧化碳(CO_2)排放量进行了22 d的短期观测,以研究不同耕作方式下土壤水分状况对土壤呼吸的初期影响.结果表明:1干土条件下在加水培养初期,3种耕作方式均产生了明显的激发效应,并且土壤呼吸速率与土壤含水量间存在正相关关系.2除干旱(30%WHC)及淹水(240%WHC、270%WHC)条件下,3种耕作方式CO_2排放通量分别为免耕>垄作>常规耕作.3对不同耕作方式下土壤水分状况及CO_2排放通量进行了方程拟合,在30%~270%WHC条件下,免耕的CO_2排放通量与水分状况拟合为二次回归方程,而垄作与常规耕作则是线性回归方程.在30%~210%WHC条件下,免耕与垄作下土壤CO_2排放通量与水分状况均可拟合为较好的对数方程,可决系数R~2分别为0.966、0.956.
The cultivation experiments of no-tillage, ridge-tillage and conventional tillage were carried out in long-term conservation tillage experiments on typical black soil in northeastern China in 2001. According to 30% and 60% of water-holding capacity (WHC) Nine water gradients were set at 90%, 120%, 150%, 180%, 210%, 240% and 270%, respectively, and their carbon dioxide (CO 2) emissions were observed for 22 days to study the effects of different tillage The results showed that under the condition of dry soil, there was a significant stimulating effect on the three tillage modes during the initial stage of hydroponics, and there was a positive correlation between soil respiration rate and soil moisture content .2 Under the conditions of drought (30% WHC) and flooding (240% WHC, 270% WHC), the CO 2 fluxes of the three tillage modes were no-tillage> ridge-tillage> conventional tillage, respectively.3 Soil moisture under different tillage systems State and CO 2 flux were fitted by equation. Under the condition of 30% ~ 270% WHC, CO 2 emission flux and water condition of no-till were fitted to quadratic regression equation, and the linear regression equation Under the condition of 30% ~ 210% WHC, the soil CO_2 row under no - till and ridge - field conditions The flux and water conditions can be fitted as a good logarithmic equation, the coefficient of determination R ~ 2 were 0.966,0.956.