Many years ago I worked with a group to control very large erosion ditches – sometimes 10 metres across. We used hardwood posts which we sank 1 metre deep into the ground, with the tops level with the original ground level. We planted them in two rows across the ditches and tied wire diagonally between them. We filled the ditch with straw or grass and planted cuttings of willows. As the level of straw and grass fell, we filled it up again.
Two years later the ground was level, the willows growing well, and the land again producing crops.
Dr William Dobson, Tecuitata, Nayarit 63777, Mexico.