Ridge tillage in Australia: a review

This paper reviews research on ridge tillage in Australia. Ridge tillage is used successfully in Australia, mainly for vegetables or irrigated crops grown on poorly drained alfisols and vertisols. The better yields from crops grown on ridges compared with those on flat land were attributed mainly to better soil aeration. Prolonged ponding of water in furrows reduced the yield of cotton and other annual crops, so that yield was best related to the rate at which the air-filled porosity recovered in the 0–0.2 m or 0.1–0.2 m depth in the ridge. However, yields will probably not reach their potential unless these fine-textured soils are either better drained through the profile and the surface is never flooded, or an optimum balance is maintained between water and air in the soil, such as with wet-soil culture. Nitrogen fertilizer, banded beneath the crop or applied in irrigation water from furrows, moved to the top of the ridge, and, without adequate rainfall during the growing season, was unavailable to the crop. New systems of ridge tillage for irrigated soybeans, fruit trees and other annual crops are described.