Any dips in which water accumulates can cause root asphyxiation and problems with passing machinery, so it is best level them. Best to remove topsoil, level subsoil, then replace topsoil. But don’t try it on wet soils.

It is important to assess the risk of erosion at this point. Erosion is influenced by:

• Slope.
• The type of soil & its structure: greater in sandy or silty soils low in humus.
• Spoils with crusts or caps will increase erosion by increasing surface run-off
• The type and depth of subsoil: shallow clay subsoils increase erosion
• The rate of rainfall: 1 – 2 mm/hr is OK, but 40 – 100 mm/hr causes erosion on most soils
• The size of droplets (larger ones run off more)
• The amount of rain that falls
• The weed control method: herbicide -> cultivation -> pasture

If there is a risk of erosion, then:

• Plant trees or dig ditches above the field
• Establish paths with ditches across field
• Lay concrete surface guttering
• Plant along the contours