Responses of rainwater conservation, precipitation-use efficiency and grain yield of summer maize to a furrow-planting and straw-mulching system in northern China

In the rain-fed areas of northern China, maize (Zea mays L.) is a main field crop, as it is well adapted to high temperatures and bright sunshine. However, low and variable rainfall and high evapotranspiration rates are common in water-limited environments during the growing season, and often mismatched rainfall events with the critical growth stages, making yield unstable. In this study, the performance of a furrow-planting and straw-mulching system was compared with the conventional flat-planting system in a double-crop culture of winter wheat (Triticum aestivum L.) and summer maize for two consecutive years (2005-2006 and 2006-2007). The four tested treatments were: conventional flat planting (F), furrow planting between ridges (B), flat planting with wheat straw-mulching (FS), and furrow planting between ridges with wheat-straw mulch (BS). Soil water content and leaf area index (LAI) were measured throughout the growing season each year, and grain yield and precipitation-use efficiency (PUEY) were determined.On average, ridge tillage combined with furrow planting increased maize yield by 430kgha-1 (7.3%) and PUEY by 10.7% (1.5kgha-1mm-1), compared with the conventional flat planting; furrow planting coupled with straw mulching increased yield by an additional 16.9% and PUEY by 19.4%, respectively. From jointing to maturity, LAI values of BS were significantly higher than those of F-system (55.6% vs. 26.1% in 2006 and 81.4% vs. 21.7% in 2007). Our data suggest that maize production adopted by furrow planting with straw-covered ridges performed best under seasonal average rainfall below 480mm, which was associated with better synchronization of seasonal soil water supply and crop needs, leading to improved maize yield and PUEY. © 2011.