科尔沁沙地灌溉与施肥对退化草地生产力的影响

Effect of irrigation and fertilizer on grassland productivity in Horqin Sandy Land

在科尔沁沙地典型退化草地上开展了裂区组合设计的灌溉与施肥二因素试验。结果表明，科尔沁沙地退化草地土壤储水量受降水量的影响强烈。由于受到干旱气候和灌溉量的影响，灌水仅对地表0～30cm的土壤含水量变化有作用，对深层土壤的含水量没有作用。灌溉和施肥对沙地退化草地的植物生物量有着明显的促进作用。灌溉处理中，灌溉90mm试验区的植被生物量为最高（128．3g／m^2），施肥处理中，每hm^2施600kg氮肥试验区的植被生物量为最高（147．3g／m^2）。灌溉90，60，30mm和对照试验区的植被耗水量分别为379．00，349．90，313．20和293．50mm。与其相应的水分利用率分别为0．28，0．38，0．34和0．35kg／（mm·hm^2）。综合分析认为科尔沁沙地退化草地的基本耗水量为294mm。

A split-plot field experiment, with watering as main plot and fertilizer as sub-plot, was conducted in degraded sandy grassland in Horqin Sandy Land. The result showed that soil water storage was significantly affected by rainfall in this grassland. Watering treatments had a significant influence on soil water storage in the 0-30 cm depths but had no significant influence deeper than the 30 cm soil layer. Both the watering and fertilizer had important roles in increasing biomass in degraded sandy grassland. The best aboveground yield from watering treatments was 128. 3 g/m^2 from 90 mm of watering and from fertilizer was 147.3 g/m^2 from 600 kg/hm^2 of fertilizer. The water consumption and WUE of treatments was 379.00 mm and 0.28 kg/（mm · hm^2） with watering of 90 mm, 349.90 mm and 0.38 kg/（mm · hm^2） with watering of 60 mm, 313.20 mm and 0.34 kg/（mm · hm^2） with watering of 30 mm, and 293.50 mm and 0.35 kg/（mm · hm^2） with watering of 0 mm. Based on comprehensive analysis, we think that the basic amount of water consumption in this grassland was 294 mm.