RESPONSE OF TOW WHEAT CULTIVARS FOR HIGH RATES OF FERTILIZATION IN GYPSIFEROUS SOILS UNDER CENTER PIVOT SPRINKLER IRRIGATION SYSTEM

Abstract

Field experiment was conducted in gypsiferous desert soil in western desert of Iraq/ to the west of Baghdad 260km. at the season 2003-2004 to study the response of wheat (Ebba-99 and Rabeha-2) to high rates of fertilization and the method of nutrient application under center pivot sprinkler irrigation system. Treatments were distributed according to the factorial experiments by using completely randomized design with three replicates in experimental units with area 300 m2. Four treatments of fertilization were used: Control, fertilization according to the recommendation of ministry of agriculture (160 kg./hec.DAP +300Kg./hec.Urea), and 40 kg. /ha. DAP was used with water or brad casting to the soil besides to recommendation fertilization. Measurements were carried out after 50,100 days and at harvesting which consisted of morphological properties like number of branches, plant height, leaf area, dry weight, number of spikes, number of grains in spike, weight of 1000 grain, biological yield, grain yield and harvesting index. Some physiological and qualitative properties were estimated that are chlorophyll a, b and total, carbohydrate, protein, total nitrogen, available phosphorus in soil and plant. Also water use efficiency was calculated. Results showed that class of Ebba-99 cultivar achieved significant increasing in yield as compared with Rabea-2. The yield was 3086 kg. /hec. For the treatment of DAP with water by significant increasing percentage about 9.82% as compared with recommended fertilization treatment ,and increased 12.6%as compared with Rabea-2 cultivar. The followed treatment was DAP added to the soil with significant increasing percentage 6.04%.The highest percentage of protein in grains were corresponded by DAP with water and reached to 17.8%. Treatments of DAP added with water or to the soil conserved good level of Nitrogen whorl cover the requirement of plant to age 100 days. But for phosphorous there was decreasing under minimum limits which cover plant requirement after 50 days. That is mentioned the importance of phosphorous application with water at later stages (after 50 days). It will be concluded the importance of fertilization with rates more than recommended quantities in gypsiferous soils conditions and adding the elements with water after age 50 days.