ZONED TILLAGE FOR POTATO PRODUCTION

Studies in southeastern Idaho evaluated the potential of tillage under the potato row (zoned tillage) to influence tuber yield and grade. Such tillage is estimated to provide significant improvement in control of water erosion. The 'Russet Burbank' variety was grown on silt loam soil under sprinkler irrigation. Major variables included 1) depth of tillage; 2) timing of tillage; 3) amount of irrigation; 4) amount and timing of nitrogen applications; and 5) depletion of soil moisture. Zoned tillage with the Tye Paratill was also compared to that of a conventional chisel. Zoned tillage did not generally affect total yield, but sometimes reduced the amount of malformed tubers. Zoned tillage tended to perform better as plant stress conditions became more severe. Late application of zoned tillage can reduce yield due to plant root disturbance. Lower soil bulk density persisted longer after zoned tillage than after conventional chiseling. The most suitable depth of zoned tillage appears to be 38 to 46 cm. Field traction conditions for zoned tillage are not favorable for large drawbar pull which will limit machine width.