(N.P.K) fertilizer application levels in Onion Crops and Using the Diagnosis and Recommendation Integrated System – DRIS

Abstract

Fertilizations is one the efforts done to increase the production and quality of crops. Nitrogen, phosphorus and potassium fertilizers rate used in the production of Onion are excessive, so the essential elements present in the soil can be imbalanced ,nutrient balance determines crop yield and quality. This research aimed to evaluate Onion productivity subjected to various ratios of(NPK) to establish the DRIS-Norms and indexes, by using leaf nutrient analysis. The Diagnosis and Recommendation Integrated System-DRIS depended on interrelation between elements, compares crop mineral nutrient proportions with DRIS-norms (Optimal values) and we can know imbalances, deficiencies and excesses in nutrient of plants .The research was conducted in the experimental farm of college of agriculture ,university of Salahaddin in Grdarash field Erbil-Iraq,3.5Km to the south of Erbil city, (36° ON, 44° 01 E), (0411359, 03997002 UTM) ,planting date 30/1/2020 and harvesting at 30/6/2020 so the research period 5 months. We used spilt – spilt design in the experiment, first factor was Nitrogen (0, 40, 80, 160 Kg.ha-1), second factor was Phosphorus (0, 80, 160 Kg.ha-1) and the third factor was Potassium (0, 50, 100 Kg .ha-1) .The results indicated that the best fertilizer combinations that recorded highest Onion-Yield (18.36 Mg. ha-1) was(K 50 Kg. ha-1, P 160 Kg. ha-1, N 40 Kg. ha-1) which had lowest Nutrient Balance Index-(NBI), its values was (9.04) but the highest value was (73.18) for (K0P0N0) treatment.