Effects of Small Amounts of Residue on Furrow Erosion

A study was conducted on a medium‐textured soil with 3% slope to determine if small amounts of plant residue placed in irrigation furrows would decrease furrow erosion to tolerable levels. Even the lowest residue rate, which was a clump of straw placed every 2 m down the furrow and equivalent to about 60 kg/ha on a total area basis, greatly reduced sediment in and turbidity of the runoff water. Erosion was essentially eliminated when furrows contained 2.2 metric tons/ha of straw along the furrow, equivalent to about 0.4 metric tons/ha on a total area basis. Inasmuch as small amounts of straw are very effective in reducing furrow erosion, it should be possible to perform limited tillage for herbicide incorporation and seedbed preparation and still leave sufficient residue in the irrigation furrows to control erosion. Techniques need to be developed for placing the residue in the furrows.