This experiment aims at testing the activity of biofertilizer, level of phosphorus and humic acid on P availability in the soil. The experiment has been executed in wood shade house of Soil and Water Resource Department College of Agriculture, Abu-Ghraib. Soil is collected from the soil surface (0-30 cm) of the field experiment, passed through the sieve of 4 mm then sterilized with methylbromide and packed at the rate of 5 kg soil / plastic pot.
The experiment involves three levels of P fertilizer (0 , 30 and 60 kg P ha-1) P0, P1 , P2, three levels of humic acid (0 , 20 and 40 kg H.A. ha-1), and two levels of biofertilizer BO (seed not inoculated) and B1 (seed inoculated with biofertilizer) and all possible combinations among these variables. There are 18 treatments each replicated three times. The N and K fertilizers were added to all experiment units at the rate of 240 kg N and 120 kg K . ha-1 . The RCD is adopted. P fertilizer and humic acid are added and mixed with soil surface in pots, and corn seed of biofertilizer treatments inoculated. Corn seeds of Var. 5018 are planted at the rate of 8 seeds pot-1 in 10-5-2013, then seedling thinned to 4 plant pot-1 after 10 days from planting. The results can be summarized as following:
1. The results from pot experiment show active biofertilizer as there is an increase in availability of P in the soil and its uptake by corn plant. Moreover, there are significant increases in dry weight, weight of corn roots by inoculating corn seed with biofertilizer.
2.There is no significant difference between 30 kg P ha-1 and 60 kg P ha-1 on the most of the studies variables (above).