Fluxes of methane and nitrous oxide in water-saving rice production in north China

Lowland rice production is currently facing serious water shortages in numerous Asian countries. In the North China Plain water limitations are severe. Water-saving rice production techniques are therefore increasingly searched for. Here we present the first study of trace gas emissions from a water-saving rice production system where soils are mulched and are kept close to field capacity in order to compare their contribution to global warming with traditional paddy rice. In a two-year field experiment close to Beijing, CH₄ and N₂O fluxes were monitored in two forms of the Ground Cover Rice Production System (GCRPS) and in traditional paddy fields using closed chambers. With paddy rice the observed CH₄ emissions were very low, about 0.3 g CH₄ m⁻² a⁻¹ in 2001 and about 1 g CH₄ m⁻² a⁻¹ in 2002. In GCRPS, the CH₄ emissions were negligible. N₂O fluxes in GCRPS were similar, 0.5 to 0.6 g N₂O m⁻² a⁻¹ in 2001 and 2002, and emission peaks mainly followed fertilizer applications. In paddy rice, N₂O fluxes were unexpectedly low throughout the year 2001 (0.03 g N₂O m⁻² a⁻¹), and in 2002 larger emissions occurred during the drainage period. So with 0.4 g N₂O m⁻² a⁻¹ the cumulative flux was similar to emissions in GCRPS. Total CO₂ equivalent fluxes calculated according to IPCC methodology were tenfold higher in GCRPS compared to paddy in 2001. In 2002, fluxes from both systems were similar with 175 and 141 g CO₂ equivalents m⁻² a⁻¹ from GCRPS and paddy. Burkhard Sattelmacher deceased.     

浅谈节水抗旱作物品种筛选

筛选节水抗旱品种,利用植物本身的生理功能调节和挖掘植物本身的节水潜力对我国北方半干旱地区具有重要意义.文中论述了"863"项目试验区对6个玉米品种的筛选过程及其产量、水分生产率的比较,并确定了该地区玉米节水抗旱作物的品种.     

迷宫式滴灌带生产及其在节水灌溉中的应用

介绍迷宫式滴灌带生产技术及其节水灌溉技术在农业生产中的应用。     

浅谈水资源合理配置

建立和完善适应市场经济体制的水权分配机制,已成为水资源管理体制改革的关键。建立规范和科学的水资源管理体制,形成有效的水权分配和交易机制,不仅有利于建设资源节约型社会,而且对落实科学发展观、实现社会的可持续发展,具有重大的现实意义。