The Effect of Organic Matter Application on Phosphorus Status in the Calcareous Soil

A field experiment is conducted to study the effect of different levels of peat (0, 25, 50, 75, and 100 Mg ha-1 to uncropped and cropped soil to wheat. Soil samples are taken in different period of time (0, 3, 30, 60, 90, 120, and 180 days after cultivation to determine (NaHCO3-Exteractable P at 3 different depths (0-10, 10-20, and 20-30 cm). Field Experiment is conducted in a randomized complete block design (RCBD) with four replicates. Wheat, Al-Rasheed variety, is cultivated as a testing crop. The entire field is equally dived in two divisions. One of the two divisions is cultivated to wheat and the second is left uncropped. The effect of five levels of peat namely 0, 25, 50, 75, 100 Mg ha-1 is investigated. Soils are fully analyzed to determine its physical and chemical characteristics. The soil samples are collected after 3, 30, 60, 90, 120, and 180 days for determining essential parameters and indicators that reflect the effect of the level of peat applications. Sodium bicarbonate - extractable P in uncropped and cropped soils at all depths, markedly decreases with time after peat application which has been attributed to plant uptake and rapid reaction of P with soil constituents. Sodium bicarbonate - extractable P with time in soil receiving 50 Mg ha-1 in both uncropped and cropped soil linearly decreases with the time of cultivation.