Investigation the Effect of Adding Fertilizer on the Crop Coefficient, Growth of Roots and Shoots of Maize Forage

In order to investigate effect of adding fertilizer on crop coefficient root and shoot growth of maize a factorial experiment in a completely randomized design with three texture treatment including silty clay loam, loam and sandy-loam soil and three fertility treatment was conducted at the experimental farm in Jey and Qahab district of Isfahan was conducted. Reference evapotranspiration and actual evapotranspiration of maize were measured by evaporation pan method and volumetric soil water balance method using micro lysimeters. The results of this study showed that using fertilizer caused increasing of crop coefficient of maize at all growth stages except for the initial stage of plant growth. Maximum and minimum effect of soil fertility on increasing crop coefficient of maize in the middle stage was equal to 37.8% in the loamy soil and 18.3% in the sandy loam soil with two percent fertilizer. The results also showed that the addition of fertilizer to the soil in each soil type significantly increased shoot yield (fresh and dry weight of shoot dry weight of leaf, stem and ear, plant height and the distance between nodes), but had no significant differences on corn root traits. The highest increase in fresh and dry weight of corn shoots loam soils, respectively 3.46% and 55.2% with the addition of two percent of the fertilizer into the soil, respectively.