Study On Ecological Field Of Sheltbelts For Farmland

Farmland originated in the mid-fourteenth century, since the eighties of the 20th century, setting off a climax on farmland researching, Construction of farmland shelterbelt has been gradually recognized by the international community. As the main shelter, farmland protection forest in the hot wind and sand disasters reduced, improving the climate, soil, hydrological conditions and also with a certain degree of negative effects. The constructions of forestry in the plains, especially in the construction of agro forestry, negative effect problem become the focus of debates between the forestry and agriculture sectors. Depth study of threatened farmland to the mechanism of control and threatened to weaken the impact of farmland as a key factor in dispute resolution. Relying on the interface theory, this study introduced the ecological field theory to research the negative effect problem of farmland shelterbelt and explore its Sphere of influence in different directions, which improved the basic ecological field theory & modeling, and also found a mutually beneficial to agriculture and forestry by the competition between the equilibrium regions, the results are as follows:(1)Belts shade help improve the soil moisture content near south of shelterbelts. The soil moisture content within 0.7H east,1.0H west and 2.OH north of the shelterbelts are greatly influenced by Forest belt. Light intensity within 0.5H north,1.7H south of shelterbelts suffers greater influence by Forest belt. The shelterbelt has the greatest impact on the north area of shelterbelts, no matter the effects or the range.(2)The range of influence that the belts have on the air temperature in south of shelterbelts can reach 1.2H; within 0.3H in north; within 0.5H in east; within 0.5H in west.(3) The area percentage of high production in shelterbelts is 59.30%; medium production is 23.38%; low production is 9.28%; lower production is 8.04%. Wheat yield rate in the shelterbelts is 9.17%. (4) Improved integrated ecological interference potential model suits to agro forestry model, the simulation of ecological interference potential are capable of reflecting shelterbelt's influence to wheat production, The order of negative effect range made by forestry belt on wheat that in shelterbelts is as follows:the south of shelterbelts> the east of shelterbelts> the west of shelterbelts> the north of shelterbelts.The balance domain of comprehensively ecological interference in south of shelterbelts is 0.7H-1.4H,0.5H-0.8H in north of shelterbelts,0.5H-0.9H in west of shelterbelts,0.6H-1H in east of shelterbelts.(5) Negative interference range made by forestry belt on wheat that in south of shelter belts is 0.7H, 0.3 H in north of shelter belts,0.4H in west of shelter belts,0.6Hin east of shelter belts.