Differences in soil structure of silt loam Typic Fluvaqents under various agricultural management practices

• Published in: Agriculture, ecosystems & environment ecosystems & environment, 1994-11, Vol.51 (1-2), p.21-42
• Main Authors: Boersma, O.H., Kooistra, M.J.
• Format: Article
• Language: English
• Subjects: CAPA ARABLE DEL SUELO; COUCHE ARABLE; ESTRUCTURA DEL SUELO; Farming system, conventional; Farming system, integrated; FARMING SYSTEMS; FAUNA DEL SUELO; FAUNE DU SOL; FLORA DEL SUELO; FLORE DU SOL; INTEGRATED PLANT PRODUCTION; LABRANZA; LOAM SOILS; PRODUCCION VEGETAL INTEGRADA; PRODUCTION VEGETALE INTEGREE; SILTY SOILS; SISTEMAS DE EXPLOTACION; SOIL FAUNA; SOIL FLORA; SOIL STRUCTURE; SOL LIMONEUX; SOL SABLOLIMONEUX; STRUCTURE DU SOL; SUELO FRANCO; SUELO LIMOSO; SYSTEME D'EXPLOITATION AGRICOLE; TILLAGE; Tillage system; TOP SOIL; TRAVAIL DU SOL
• ISSN: 0167-8809; 1873-2305
• DOI: 10.1016/0167-8809(94)90033-7

Soil structure was studied in five farming systems to trace the contribution of soil organisms to soil structure formation. These farming systems were: a conventional high-input system; an integrated system, i.e. reduced N-fertilisation, reduced biocide use and shallower tillage; a new minimum tillage system with only 7 cm ploughing (started in 1986); an old minimum tillage system with only 7 cm ploughing (started in 1967) and an old pasture land (started in 1966). These farming systems were developed in the same parent material, viz. sedimentary calcareous silt loams classified as Typic Fluvaquents. To determine the impact of different structure-forming agents on the resulting soil structure, the following soil attributes were studied: field soil structure, susceptibility to surface slaking and crust formation, total porosity in relation to the macroporosity, soil micromorphology with respect to biological impact on soil structure and internal slaking. The impact of different farming systems was restricted to the topsoil (0–30 cm depth) in the arable farming systems and to 42 cm depth in the old pasture. Topsoils of all farming systems had a different soil structure. Of the arable systems, the old minimum tillage had the best overall structure and was largely formed by soil organisms (over 10%). The integrated system had a better overall structure than was observed in the conventional system and was also largely formed by soil organisms. However, this system showed distinctly less biological influence than the old minimum tillage system. Primary biological voids in the integrated system comprised less than 5% and the mean macroporosity was 5% of the total soil volume. The new minimum tillage system had the worst soil architecture with less than 5% primary biological voids and a mean macroporosity of 3%. Old pasture land had a strong biologically generated structure (over 10%) largely formed by earthworms, but was not distinctively better than the soil architecture in the old minimum tillage system. Comparison over the years 1985, 1987 and 1990 showed no clear trends in overall changes in soil architecture of the integrated system, except for the impact of soil organisms on the soil architecture increasing from less than 2% to over 5%. Correlation of the impact of different groups of soil organisms on the soil structure and the populations could not be made, as no functional groups based on contribution to soil structure were distinguished. Reducing soil t