On-farm assessment of tillage impact on the vertical distribution of soil organic carbon and structural soil properties in a semiarid region in Tunisia
On-farm assessment of tillage impact on the vertical distribution of soil organic carbon and structural soil properties in a semiarid region in Tunisia
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DOI：
10.1016/j.jenvman.2012.05.029
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发表时间：
2012-12-30
影响因子：
8.7
通讯作者：
Gallali, Tahar
中科院分区：
文献类型：
--
作者：
Jemai, Imene;Ben Aissa, Nadhira;Gallali, Tahar
在半干旱地区，降雨量少且不稳定，再加上农业对土壤的大量使用，耗尽了土壤的有机碳，降低了土壤的化学、生物和物理肥力。为了制定有效的土壤管理办法，迅速恢复严重退化的土壤，采用了免耕、覆盖耕作制度。因此，在一个农场进行了一项研究，以评估免耕系统（NT）与常规耕作（CT）对土壤有机碳（SOC）、容重（BD）、总孔隙度（TP）、结构不稳定性（SI）、稳定的团聚体和渗透系数（Ks）在粘壤土雨水灌溉条件下，在突尼斯西北部的半干旱地区。CT由犁板犁到20厘米的深度用于连续小麦生产。在小麦/蚕豆轮作和小麦/苏拉轮作中，通过在残留物下直接钻孔的NT分别使用了3年（NT 3）和7年（NT 7）。在0-10 cm和0-20 cm土层，NT 3和NT 7处理的土壤有机碳含量比CT处理的增加更显著（p < 0.05），但NT 7处理的土壤有机碳含量在最上层10 cm土层的增加更显著。NT 3管理减少BD，从而增加TP在0-10 cm的深度。在0-30 cm深度处观察到NT 7处理的相同趋势。Ks不受NT 3处理的影响，但在0-30 cm深度处通过NT 7处理得到改善。在NT 7样地中，BD、TP和Ks的变化仅在前10 cm的土壤中显著。NT 3和NT 7均显着降低了整个土壤剖面的SI（p < 0.1）并增强了稳定团聚体（p < 0.05）。这些差异在NT 7下0-10 cm深度处最为明显。所选土壤特性的分层比（SR），除了SI，显示CT和NT试验之间的显着差异，表明土壤质量的改善。在这项研究中，突尼斯西北部的耕作系统中的NT管理被证明是提高土壤质量，特别是在表层，通过增加有机碳的储存和提高土壤的物理性质。这些影响在长期内最为明显。(C)2012爱思唯尔有限公司保留所有权利。
In semiarid areas, low and erratic rainfall, together with the intensive agricultural use of soils, has depleted soil organic carbon and degraded the soil's chemical, biological and physical fertility. To develop efficient soil-management practices for the rapid restoration of severely degraded soils, no-till, mulch-based cropping systems have been adopted. Thus, a study was conducted on a farm to evaluate the effect of a no-tillage system (NT) versus conventional tillage (CT) on the vertical (0-50 cm) distribution of soil organic carbon (SOC), bulk density (BD), total porosity (TP), structural instability (SI), stable aggregates and infiltration coefficient (Ks) in a clay loam soil under rain-fed conditions in a semiarid region of northwestern Tunisia. CT consisting of moldboard plowing to a depth of 20 cm was used for continuous wheat production. NT by direct drilling under residue was used for 3 (NT3) and 7 (NT7) years in wheat/fava bean and wheat/sulla crop rotations, respectively. SOC was more significantly increased (p < 0.05) by NT3 and NT7 than by CT at respective depths of 0-10 and 0-20 cm, but a greater increase in the uppermost 10 cm of soil was observed in the NT7 field. NT3 management decreased BD and consequently increased TP at a depth of 0-10 cm. The same trend was observed for the NT7 treatment at a depth of 0-30 cm. Ks was not affected by the NT3 treatment but was improved at a depth of 0-30 cm by the NT7 treatment. Changes in BD, TP and Ks in the NT7 plot were significant only in the first 10 cm of the soil. Both NT3 and NT7 considerably reduced SI (p < 0.1) and enhanced stable aggregates (p < 0.05) across the soil profile. These differences were most pronounced under NT7 at a depth of 0-10 cm. The stratification ratio (SR) of the selected soil properties, except that of SI, showed significant differences between the CT and NT trials, indicating an improvement in soil quality.NT management in the farming systems of north-western Tunisia was demonstrated in this study to improve soil quality, especially in the surface layers, by increasing storage of organic carbon and enhancing the physical properties of the soil. These effects were most pronounced in the long term. (C) 2012 Elsevier Ltd. All rights reserved.