Effect of organic compounds on acid and alkaline phosphatase activity in some soils of Iran

Phosphorus availability in soils is largely depended on acidic and alkaline phosphatase activities. Soil organic matter content is one of the most important factors influencing the activity of those f enzymes. The present experiment was carried out in a randomized complete block design with three replications on corn planting time in four provinces of Khuzestan, Khorasan, Fars and Mazandaran. Treatments included chemical phosphorus fertilizer (P 100%), caw manure (P0 M2) 20 tons per hectare, organic fertilizer (P0 M4) 20 tons per hectare, the first treatment plus second treatment (P100% M2), the first treatment plus third treatment (P100% M4) and without any chemical phosphorus fertilizer and manure (P0 M0) as control. In all provinces cow manure was used but organic fertilizers were different in each province. In Mazandaran, compost of wood and paper industries; In Khorasan, compost of municipal waste; In Khuzestan, sugar cane bagasse compost and in Fars, municipal homemade was used as organic fertilizer. From each province 36 samples (before and after planting) were collected and a total of 144 samples were analyzed. The results of different treatments showed the positive effect of the simultaneous use of vegetation and organic fertilizers on acidic and alkaline phosphatase in soil samples. In all Provinces, the mean activity of alkaline phosphatase before and after corn planting period, was higher than acidic phosphatase.