Wheat is an important cereal crop of Saudi Arabia grown on an area of 250,000 ha with an annual production of 1,260,000 metric tons. The crop is cultivated on sandy soils using sprinkler irrigation under center pivots. The crop is sown in November and harvested in April. Efficient use of nutrients and irrigation water under such conditions would result in improving wheat yields and increasing profitability. Investigations are underway to understand the spatial variability in soil properties and determine the most optimum fertilizer dose and irrigation regime for obtaining higher grain yields of wheat. The research is being carried out in TE 11 pivot (50 ha area) of Todhia farm of H.H. Prince Sultan Bin Mohammed Bin Saud Al Kabeer. Management zones in the pivot were delineated based on different criteria such as bare soil satellite imagery, soil EC and historic NDVI. A field experiment was laid out in this pivot in Split Plot design with three replications. Four irrigation treatments consisting of Irrigation at 100, 90, 80 and 70 % Evapotranspiration (ET) were randomly allocated to the main plots and three fertilizer treatments consisting of 300:150:200; 400:250:300 and 500:300:300 kg N: P2O5:K2O per ha were randomly allocated to the sub-plots. The area covered by two spans formed each replication. The results of the study are presented in this paper.
