Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 1, 2001
Publication Date: June 1, 2002
Citation: ALVA, A.K., HODGES, T., BOYDSTON, R.A., COLLINS, H.P. EFFECTS OF IRRIGATION AND TILLAGE PRACTICES ON YIELD OF POTATO UNDER HIGH PRODUCTION CONDITIONS IN THE PACIFIC NORTHWEST. COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS, 33:1451-1460. 2002. Interpretive Summary: The Columbia Basin region in the Pacific Northwest of the United States represents a premium potato production area with highest per acre yields of high quality potato tubers in the country. The mean rainfall in this region is < 180 mm, thus irrigation is critical for growth of the plants, and optimal tuber yields. Deficit irrigation (85 percent of evapotranspiration) )decreased the tuber yield of two potato varieties (Russet Burbank and Hilite Russet) as compared to that of the plants which received irrigation to replenish full evapotranspiration. Generally, soil preparation for potato production includes ridges and furrows with dammer-dike to conserve the soil moisture. However, three years of field study showed no signifi- cant difference in tuber yields between the conventional soil preparation as explained above, and the reduced tillage, i.e. flat planting. This study demonstrated in coarse textured soil with adequate water infilration, ,excessive tillage and/or dammer-dike may not provide additional benefits for increased production or tuber quality.
Technical Abstract: The soil and climate conditions prevalent in the Pacific Northwest region are favorable for production of high potato (Solanum tuberosum L.) yields. Much of this production occurs on coarse, low organic matter, sandy soils which can be subject to wind and water erosion, and excessive leaching of water and soluble agrichemicals below the root zone, particularly when irrigation is not managed adequately. Tuber production and quality are adversely impacted when potatoes are subjected to water stress. Therefore, optimal irrigation scheduling is important to support high production of good quality tubers and to minimize potential adverse impacts on water quality. Effects of two irrigation regimes and three tillage practices on production of two potato varieties were studied under four years rotation with either corn (Zea mays L.) or wheat (Trilicum aestivum L.). In two out of three years, as compared to irrigation to replenish full ET deficit irrigation [85% of evapotranspiration (ET)] decreased total tuber yield by 8 to 11 percent and 10 to 17 percent, and U.S. No. 1 tuber yield by 5 to 17 percent and 16 to 25 percent, in Russet Burbank and Hilite Russet cultivars respectively. Tillage treatments evaluated were: (i) conventional including raised ridges with dammer-dike; (ii) optimal, i.e. lower depth of the tillage and shallow furrow; and (iii) reduced tillage, i.e. flat planting. The effects of tillage treatments were non-significant on the total as well as U.S. No. 1 tuber yield in both cultivars, except in 1995, the tuber yield was significantly lower in flat planting treatment as compared to that in the other tillage treatments.