Effect of different levels of organic fertilizer and phosphorus on yield, quality and nutrient balance of corn.


This investigation was conducted at Grdarasha field, College of Agriculture ,University of Salahaddin ,Erbil with GPS reading of (Latitude: 36.11 deg. N, Longitude: 44.00 deg. E, Altitude: 434 meters above sea level). The study included the effect of 6 levels of organic fertilizer (0,20,40,60,80 and 100) tons ha-1 which equivalent to (0, 0.5, 1. 0 , 1.5 , 2.0 and 2.5)% of soil weight of experimental unit) and 2 levels of triple super phosphate (TSP) (0 and 160 kg P2O5 ha-1 which equivalent to( 0 and 72) kg P ha-1 and their interaction on , N, P , K availability , nutrient balance , yield and quality of corn plant. The results indicated that the increase in application of organic fertilizer caused (11- 36%)increase in corn yield .The significant correlation coefficient was recorded between each of yield and relative yield with nutrient balance index(NBI)values, with correlation coefficient value of (r=0.56* and 0.56*respectively). Application of phosphorus fertilizer without organic matter caused 5% increase in yield ,while with organic fertilizer reached to 36% increase .On the other hand depending on nutrient balance index (NBI) values the application of organic fertilizer caused 4 times decrease in NBI comparing with control treatment. The phosphorus status of control treatment depending on P-index value was very low in control treatment which was (-30.40) while application of organic fertilizer solved this problem or increase in the mentioned index to positive value (3.63).