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Water is the most limiting factor for crop production in dryland farming. A better understanding of the long-term impact of tillage and residue management systems on soil structure and water infiltration is necessary for the further development of conservation tillage practice to improve water use efficiency. The objectives of this study were to assess the influence of no-till with residue retention (NT) and conventional (plough) tillage with residue removal (CT) on soil properties and soil water transmission characteristics in a winter wheat (Triticum aestivum) monoculture system in Shanxi, on the Chinese Loess Plateau. Soil physical parameter measurements were made in the top 30 cm depth in September 2007 after 16 years under the two tillage treatments. Compared with CT treatment, NT significantly (P < 0.05) reduced soil bulk density (7.1%) in the 20-30 cm soil layer, and increased macroporosity (>60 µm, 17.0%) and saturated hydraulic conductivity (249%) in the 15-30 cm soil layer. There were no significant differences in these soil physical properties between tillage systems in the 0-15 cm layer. In addition, plant available water and water infiltration rate were greater in the NT treatment. The improved soil quality parameters and water infiltration from this long-term experiment indicate that no-tillage with residue retention is a promising farming system for the dryland farming areas of northern China.

Challenges for dryland farming on the Loess Plateau of China are continuous nutrient loss, low soil organic matter and crop yield, and soil degradation. Controlled traffic, combined with zero or minimum tillage and residue cover, has been proposed to improve soil structure and crop yield. From 1998 to 2006, we conducted a field experiment comparing soil organic matter and wheat productivity between controlled traffic and conventional tillage farming systems. The field experiment was conducted using 2 controlled traffic treatments (zero tillage with residue cover and no compaction, shallow tillage with residue cover and no compaction) and a conventional tillage treatment. Results showed that controlled traffic treatments significantly increased soil organic matter and microbial biomass in the 0–0.30 m soil profile. Controlled traffic with zero tillage significantly increased total N in the 0–0.05 m soil profile. The mean yield over 8 years of controlled traffic treatments was >10% greater than that of conventional tillage. Controlled traffic farming appears to be a solution to the cropping problems faced on the Loess Plateau of China.

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Controlled traffic zero and minimum tillage management with residue cover has been proposed as a solution to erosion and other soil degradation challenges to the sustainability of dryland farming on the Loess Plateau of China. This was assessed between 1998 and 2007 in a field experiment involving a conventional tillage treatment, and 2 controlled traffic treatments, no tillage and shallow tillage, with full straw cover in both cases. This paper reports the soil physical properties after 9 years of dryland wheat production under these treatments, and the substantial improvements seen in soils under controlled traffic. Compared with conventional tillage, controlled traffic significantly reduced soil bulk density in the 0–0.15 m soil layer, and increased total porosity in the 0–0.60 m soil layer, where macroporosity (>60 µm) and mesoporosity (0.2–60 µm) increased at the expense of microporosity (<0.2 µm). Readily available water content and saturated hydraulic conductivity were greater in controlled traffic treatments. Controlled traffic farming appears to be an improvement on current farming systems on the Loess Plateau, and valuable for the sustainable development agriculture in this region.