Seasonal changes of physical properties of an Oxic Paleustalf (Red Kandosol) after 16 years of direct drilling or conventional cultivation

• Published in: Soil & tillage research 1998-11, Vol.49 (1), p.65-77
• Main Authors: Suwardji, P, Eberbach, P.L
• Format: Article
• Language: English
• Subjects: Aggregate stability; Agronomy. Soil science and plant productions; Biological and medical sciences; CEREAL CROPS; CERO-LABRANZA; CONVENTIONAL TILLAGE; Cropping systems. Cultivation. Soil tillage; CULTIVOS DE CEREALES; DENSIDAD DEL SUELO; DENSITE DU SOL; DIRECT SOWING; Earthworms; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Generalities. Cropping systems and patterns; GRAIN LEGUMES; Hydraulic conductivity; LABRANZA CONVENCIONAL; LABRANZA MINIMA; LEGUMINEUSE A GRAINS; LEGUMINOSAS DE GRANO; Macroporosity; MINIMUM TILLAGE; NEW SOUTH WALES; NON TRAVAIL DU SOL; NOUVELLE GALLES DU SUD; NUEVA GALES DEL SUR; OLIGOCHAETA; PERMEABILIDAD; PERMEABILITE; PERMEABILITY; Physical properties; Physics, chemistry, biochemistry and biology of agricultural and forest soils; PLANTE CEREALIERE; POROSITE DU SOL; SEMIS DIRECT; SIEMBRA DIRECTA; SISTEMA POROSO DEL SUELO; SOIL DENSITY; SOIL PORE SYSTEM; Soil science; SOIL SORPTION; SORCION DEL SUELO; SORPTION DU SOL; Structure, texture, density, mechanical behavior. Heat and gas exchanges; Tillage methods; TRAVAIL DU SOL CONVENTIONNEL; TRAVAIL DU SOL MINIMAL; ZERO TILLAGE
• ISSN: 0167-1987; 1879-3444
• DOI: 10.1016/S0167-1987(98)00149-4

Oxic Paleustalf soils, as occurring in the Wagga Wagga region of New South Wales, are widely used for cereal and pulse cropping. However, the surface structure of these soils declines when frequently cultivated. In recognition of this problem, direct drilling of crops on these soils is advocated by agricultural advisory staff, and in 1977 a long-term trial was established to contrast differences that may develop over time in soil properties and in crop yield. The present study was conducted to evaluate the effect of 16 years of tillage practices, on these soils, on some physical and biological properties, such as macroporosity, water stability of aggregates from the 0–5 cm and 5–10 cm layers, and surface-layer saturated ( K sat) and unsaturated ( K-40) hydraulic conductivity. The tillage treatments at this site consisted of (i) conventional cultivation (CC), i.e. three cultivations before sowing; (ii) reduced cultivation (RC), i.e. one cultivation before sowing and a knockdown herbicide; and (iii) direct drilling (DD), i.e. no cultivation before sowing and a knockdown herbicide. Temporal changes in aggregate stability and hydraulic conductivity were observed during the growing season. Aggregates sampled at four time intervals from the surface (0–5 cm) layer were more stable under DD than under RC nor CC at each sampling ( P