文献类型： 会议论文

第一作者： Destain M.-F

作者： Destain M.-F ¹ ; Roisin C ² ; Mercatoris B.C.N. ¹ ;

作者机构： 1.ULg (GxABT), 2 Passage des Deportes, 5030 Gembloux (Belgium)

2.CRA-W, 9 Rue de Liroux, 5030 Gembloux (Belgium)

关键词： Soil tillage;compaction;porosity structure;mercury intrusion porosity;soil strength

会议名称： Annual International Meeting of the American Society of Agricultural and Biological Engineers

主办单位：

页码： 878-890

摘要： The effects of long-term use (8 years) of two different tillage systems were assessed on a Luvisol, under temperate climate (Belgium). The tillage treatments were (i) conventional tillage (CT) with moldboard ploughing to 27 cm depth and (ii) reduced tillage (RT) with a spring tine cultivator to 10 cm depth. The measurements included bulk density (BD) and precompression stress (Pc) chosen as indicators of mechanical strength, and the pore size distribution (PSD) measured by mercury intrusion porosimetry (MIP). The tillage systems, the depth and their interaction had a significant effect on BD, Pc and PSD.In CT, in the topsoil, the soil strength was low and the total porosity n was about 50 %. In the subsoil, n decreased to 43 %. The PSD of CT was uni-modal in topsoil and subsoil in the MIP measurement range. The mean value of the mode r_(max) diminished from the topsoil toward the subsoil (from 2.5/.im to 1.9pm).In RT, in the topsoil, the soil strength was higher than CT. BD did not vary much according to the depth. The total porosity n of RT was comprised between 40-45 % in the soil profile. The PSD was uni-modal and r_(max) increased from topsoil (s2/.im) to subsoil (> 3/im). This suggested the agglomeration of fine particles under the long-termaction of mechanical loads, climatic agents, biological organisms or clay minerals acting as cementing agents. These phenomena could be at the origin of the increase of Pc with the depth without significant modification of BD. Such high values of Pc could be responsible of negative effects on root-growth leading to a more superficial root lateral development.

分类号： S-532