旱作农田沟垄微型集雨结合覆盖玉米种植试验研究

On-Field Ridge and Furrow Rainwater Harvesting and Mulching Combination for Corn Production in Dry Areas of Northwest China

田间沟垄微型集雨结合覆盖技术有效地利用了膜垄的集水和沟覆盖的蓄水保墒功能,改变了降雨的时空分布,使降雨集中富集在种植沟中,显著地提高了降水的利用效率,特别是小雨的利用率。研究结果表明:土垄的平均集水效率为7% ,而垄上覆膜后集水效率为87% ,膜垄能产生径流的最小降雨量为0 8mm。田间沟垄微型集雨结合覆盖技术能提高土壤贮水量,增加玉米的产量。垄上覆膜结合沟覆盖处理玉米产量比平地增加2 339～5 2 97kg/hm2 (44 %～14 3% ) ,水分利用效率基本都在2kg/m3 以上。

The on-field ridge and furrow rainwater harvesting and mulching combination system was built by shaping the soil surface with alternate ridges and furrows along the contour. The plastic-covered ridges served as a rainfall harvesting zone and furrows as a planting zone. This system can significantly improve rainwater use efficiency by concentrate rainwater into the furrow through the plastic-covered ridge and particularly can make better utilization of light rain. Some materials were also used to mulch the furrows to reduce soil evaporation and thereby increase the effectiveness of the harvested water. The results indicated that plastic-covered ridge had an average runoff efficiency (runoff/rainfall) of 87% as compared to 7% for bare ridge, and it could generate runoff at a threshold value of 0.8 mm rainfall. Moreover, this system can increase soil water storage and grain yields. Grain yields in the system with mulches were significantly higher than the controls, with an increase of 2 339～5 297 kg/hm^2 (44%~143%). In most treatments, the water use efficiencies (WUE) were in excess of 2.0 kg/m^3.