梯田田埂栽植萱草的固土防蚀效果及经济效益分析

为了解决梯田田埂的固土防蚀问题,以萱草为试验材料,采用试验室生理指标测定、护根苗种植和径流小区观测等方法对萱草种植保活技术、固土防蚀效果及经济效益进行了研究。结果表明,萱草的临界饱和亏为66.73%,第16天时叶片失水率为98.43%,具有较强的抗旱能力。梯田田埂土壤水分受田埂侧面蒸发的影响,其水分亏缺值随距田埂的距离增大而减小;而土壤养分则是田埂附近比田中间高,存在一定程度的积累;护根苗种植的成活率远远高于裸根苗;单株萱草根系固土量8年植株达到最大,为69.2kg;20°坡面种植萱草后年均土壤侵蚀模数（t/km^2）比对照低54.9%,年清水径流深分别比对照低53.7%,固土防蚀效果显著;梯田田埂种植萱草后,对其2m范围内的作物产量产生影响,但萱草收入远远大于作物减产的损失。

Studies on the Keeping-alive Planting Techniques and Fixing-soil Antierosion Effects of Hemerocallis fulva on Terrace Ridges

In order to solve the problems of soil-fixation and erosion-resistance of terrace ridge, we did some research about planting and keep-alive technology of Hemerocallis fulva, the effects and economic benefits of soil-fixation and erosion-resistance. We finished the research by laboratorial determination of physiological index, planting root-protective seedlings, observation of runoff plots, and use Hemerocallis fulva as experimental material. The results showed that the critical saturation deficit of the Hemerocallis fulva was 66.73%. The leaf water loss rate was 98.43% at the 16th day, with strong drought resistance. The soil moisture in the terrace ridges was affected by the evaporation from the ridge sides. The soil water deficit value decreased with the increase of the distance away from the ridge side, but the soil nutrient content was higher near the ridge than in the middle of the terrace. The planting survival rate of the root-protected seedlings was much higher than that of the bare-root seedlings. Soil-fixed weight of the roots of the single eight-year-old Hemerocallis fulva was 69.2 kg, reaching the maximum. Compared with the control, planting Hemerocallis fulva on slope decreased the average annual soil erosion modulus (t/km2) and the annual fresh water runoff depth by 54.9% and 53.7%, respectively. Therefore, planting Hemerocallis fulva on slope had significant effects on soil fixation and antierosion. Hemerocallis fulva planted in terrace ridge will affect the yield of neighboring crops 2 meters around. But the gain from planting Hemerocallis fulva will be far greater than the loss caused by crop yield reduction.