Abstract

In this study, interactive effects of different potassium application and water restrict on: root penetration at Iran. The experimental unit had designed by achieved treatment in factorial on the basis completely randomized block design with three replications. Certain factors including potassium and non-potassium applications (0 and 200 kg/ha), certain field crops (maize, sorghum and millet) and water supply were studied. In this study crops water supply was determined by indicated irrigation conditions by keeping leaf relative water content  (RWC) > 95% (non-drought stress condition or irrigation conditions) and drought condition by RWC = 60 - 70%. We noticed, however K fertilizer significantly increased the root penetration of plants. Although the non-drought stress treatment significantly increased root penetration and highest root penetration of maize was achieved under irrigation conditions (non-drought), but the highest roots penetration of sorghum and millet were indicated under the drought condition. Whereas K application persist less damaging of drought stress result and it enabled plant to significantly grew its  root and penetrating along soil depth under the drought condition. Our finding may give applicable advice to farmers and agricultural researchers for management and concern on fertilizer strategy and carefully estimate soil potassium supply within arid or semi arid regions as most challengeable issues of environmental safety.

Key words: Potassium fertilizer, drought stress, root penetration, maize, sorghum, millet.