tailieunhanh - Erosion control in the tropics - Part 8

8 Underlying causes of erosion In the previous chapters we have seen how the chance of erosion can be lessened by taking certain precautions. However, circumstances are sometimes such that a farmer cannot adopt another method of production that would be less damaging. | 8 Underlying causes of erosion In the previous chapters we have seen how the chance of erosion can be lessened by taking certain precautions. However circumstances are sometimes such that a farmer cannot adopt another method of production that would be less damaging. So we are confronted with the underlying cause of erosion. A simple comparison can be made here with a farm track it is sometimes forgotten that roads and paths can be a serious erosion hazard . Naturally a road is seldom covered with a protective mulch layer moreover roads are preferably laid out as straight as possible if necessary straight through an erosion prone area straight up a hill. This is for the simple reason that roads are laid out to transport people and products and not to control erosion. Just as it is for the road in our example so is it too in agriculture agriculture is primarily for food production or as a money earner. The choices that are made in agriculture basically have an economic social or agronomic background. Thus it is very important to study these backgrounds carefully when asking yourself why erosion occurs in a certain area. Not only will the deeper causes of erosion be found in the socio-economic backgrounds but the incentive will be found which motivates the farmer to alternative land use which would have less disastrous results for the soil. Crop choice In Chapter 5 the importance of a good crop choice was pointed out. However the choice of crop is not free. Under given circumstances some crops would dry out others require tillage for which there are no machines. Some crops don t protect the soil well such as maize or cassava but they are staple food. People are dependant on these crops for survival. Mulch Farmers in certain areas used to use mulch before but not any more. The reason for this is probably the increasing population pressure which brings with it an increasing need for fuel. The grasses that are Underlying causes of erosion 73 there and the residues of .

• Nông nghiệp
• chống sói mòn
• sói mòn đất đai
• kĩ thuật canh tác
• kĩ thuật trồng trọt
• tài liệu nông nghiệp
• Dẫn liệu hình thái giải phẫu
• Giải phẫu loài rù rì
• Loài rù rì trồng ven sông suối
• Phòng chống sói mòn
• Phòng chống sạt lở