Effect of Irrigation Water Salinity and Iron Fertilizers on Soil Salinity, Growth and Yield of Cucurbita pepo (L.)

Abstract

This study was conducted in the horticulture field , college of Agriculture, University of Al-Qasim Green, during the spring season of 2014 in loamy soil under drip irrigation system to study the effect of two levels ( 1.4 , 4 dS.m^-1 ) of irrigation water salinities and methods of application of two sources of iron fertilizers on soil salinity , some growth parameters , yield and percentage of response to iron by Cucurbita pepo (L ). ,  and iron availability in surface soil . Chelate - Fe EDDHA (6%Fe), and FeSO₄.7H₂O(20%Fe) iron fertilizer sources were used in this study. Each fertilizer source was applied at a rate of 10 kg Fe.ha^-1 by soil application at two equal doses ; first dose was after two weeks from transplanting and other dose is after six weeks; and by foliar application: Fe – EDDHA and FeSO₄.7H₂O fertilizers were sprayed on the plants at six times, the first was after two weeks from transplanting and the others were at week intervals from transplanting.Organic manure at a rate of 16 ton.ha^-1 was added to the soil two months before transplanting. Urea was added to the soil at a rate of 400 Kg.ha^-1 with four equal doses through the growing season while Di ammonium Phosphate (DAP) at a rate of 200 Kg.ha^-1 and Potassium sulfate at a rate of 200 Kg.ha^-1 were added to the soil before transplanting. Split – split plot design with three replicates was used. Results of the study can be summarized as follows:Soil salinity and available soil – Fe concentration after harvest were increased by 82% , 6% and chlorophyll content , plant - Fe , dry matter ,yield were decreased by 20% , 13% , 43% , 22% respectively with increasing irrigation water salinity from 1.4 to 4 dS.m^-1. High response for soil applications of iron compared with foliar applications and for chelated iron fertilizer compared with mineral iron fertilizer was observed.

Keywords: water quality  ,  Iron availability.