| Water and soil preserving function of planting grass on slope under natural rain condition was systematically studied.The masterstroke is selecting grass species,utilization of grassland,extending grassland greatly,and influential factors on water and soil loss is assistant line of the research.It studies correlative indices for exploring eminent grass whose effect of prevention and cure of water and soil loss is preferably good.The results showed:1.It had correlation between water and soil loss amount and types of vegetation.The radicel in the section of planting grass relatively developed,combined with the soil tightly,reduced loss of sand.In the section of planting crop,loss of the sand was more,because of plough up the soil when planting and bareness after its harvest.2.The order of runoff of the six grass species was as follows:Festuca arundinaceae > James > Agropyron smithii > Bozoisky > Bromus inermis > Bromus biebersteinii;The order of erosion modulus of the six grass species was as follows: Festuca arundinaceae > James > Bozoisky > Agropyron smithii > Bromus biebersteinii > Bromus inermis.3. Planting Zea mays and Bromus biebersteinii had function of prevention and cure on slope,Planting Zea mays can reduce annual runoff and soil erosion modulus by 18.9% and 65.9%,but Planting Bromus biebersteinii can reduce annual runoff and soil erosion modulus by 98.2% and 99.9%,capability of protecting water and solidifying soil was 5.2 and 1.5times as much as planting Zea mays. The effect of prevention and cure of water and soil loss was better than Zea mays.4. It had correlation between water and soil loss and leaf area index of vegetation on slope.The more leaf area index was,the more coverage of vegetation was, decreased soil erosion of slope.In June of the next year,leaf area index was 7.24 and the coverage 91.5%, 11.4 and 2.2 times as much as planting Zea mays. Compared with Zea mays, planting Bromus biebersteinii was more propitious to prevention and cure of water and soil loss in former period, reduced annual runoff and soil erosion modulus.5.The runoff amount between the two different treatments are significantly,but the soil erosion amount are not significantly at 0.05level,it also means that the effect of keeping water was better than keeping soil of planting grass on slope. |
