A greenhouse pots experiment has been carried out using silty clay loam soil collected from Agronomy department field/College of Agriculture / University of Baghdad to study the behavior and effects of adding different phosphate sources and compost on wheat growth and soil content of phosphor in two stages of wheat growth (tillering& spikes formation). Wheat seeds Triticumaestivum L. are grown in 26/11/2013. Completely randomized block design (CRD) has been used and three mineral phosphate sources، phosphate rock PR (Ecashat region، Iraq),partial Acidulated phosphate rock PR (40 %) (PAPR) and Tri super phosphate (TSP) has been added at one rate (100 kg. p. ha-1 ) by mixing with soil before planting with two levels of compost 0 and 20 mega gram.ha-1 .The available soil phosphor and wheat growth parameters such as plant height , number of tillers , dry weight of vegetation and root plants and total dry weigh of plant are measured at tillering stage and spikes formation stage.
The results show that addition of the mineral phosphate sources and compost and their interaction show significant increases in soil available phosphor values. TSP addition gives the best significant differences followed by PAPR while addition of the phosphate rock does not give asignificant difference compared with the control at the two wheat growth stages. The percentages of increases in the average of the soil available phosphor are 32.7% , 12.81% at tillering and spikes formation stages in TSP and PAPR treatments respectively, and 46.7% , 42.8 % at tillering and spikes formation stages respectively when compost was added and 13. 61% at tillering stage and 11.4 %at spikes formation stage in interaction of compost with TSP. The addition of the mineral phosphate sources and compost and together show positive significant effects in most of growth parameters such as plant height ,tillers number and roots dry weight at spikes formation stage and total dry weight of plant , weight of straw at tillering and spikes formation stages .The TSP treatment is the best followed by PAPR treatment in increasing the last growth parameters compared with PR at which non-significant increases are recorded .