Xirui Zhang

Influence of conservation tillage practices on soil properties and crop yields for maize and wheat cultivation in Beijing, China

Conservation tillage is becoming increasingly attractive to farmers because it involves lower production costs than does conventional tillage. The long-term effects of sub-soiling tillage (ST), no tillage (NT), and conventional tillage (CT) on soil properties and crop yields were investigated over an 8-year period (2000–07). The study was conducted in a 2-crop-a-year region (Daxing) and a 1-crop-a-year region (Changping) of the Beijing area in China. At 0–0.30 m soil depth, water stability of macro-aggregates (>0.25 mm) was much greater for ST (22.1%) and NT (12.0%) than for CT in Daxing, and the improvements in Changping were 18.9% and 9.5%, respectively. ST and NT significantly (P   CT at both sites. Consequently, crop yields in ST and NT plots were higher than in CT plots due to improved soil physical and chemical properties. Within the conservation tillage treatments, despite similar economic benefit, the effects on crop yields for ST were better than for NT. Mean (2000–07) crop yields for ST were 0.2% and 1.5% higher than for NT at Daxing and Changping, respectively. We therefore conclude that ST is the most suitable conservation tillage practice for annual 2-crop-a-year and 1-crop-a-year regions in the Beijing area.

Spring wheat performance and water use efficiency on permanent raised beds in arid northwest China

Permanent raised beds have been proposed as a more productive and water-efficient alternative to the conventional system of flat, flood-irrigated bays for planting narrow-spaced crops in arid north-west China. Data from a field experiment (2005–2007) conducted in the Hexi Corridor at Zhangye, Gansu Province, China, were used to compared the effects of traditional tillage (TT), zero tillage (ZT), and permanent raised beds (PRB) on crop growth, yield, and water use in a spring wheat monoculture. The results show that PRB significantly (P < 0.05) increased soil water content to 0.30 m depth by 7.2–10.7% and soil temperature to 0.05 m depth by 0.2–0.9°C during the wheat-growing period relative to TT and ZT treatments. Bulk density in 0–0.10 m soil layer under PRB was also 5.8% less than for flat planting treatments. Mean wheat yields over 3 years on PRB plots were slightly greater and furrow irrigation in permanent beds was particularly effective in increasing irrigation water use efficiency (~18%), compared with TT and ZT treatments. This increase in water use efficiency is of considerable importance for these arid areas where irrigation water resources are scarce.