Phosphorus Supplying Capacity of Soils and Their Relationship with Phosphorus Removal by Maize

A greenhouse experiment was carried out to study the Q/I relationship of P in ten soils of Haryana and to correlate their supply parameter values with the uptake of P by maize. Application of increasing levels of P resulted in enhanced dry matter yield and P uptake of maize in almost all the soils. Supply parameter values, calculated by the expression (K₁ K₂)^1/4 (qc/K₁ K₂)^1/2 increased with P levels and had a wide range of variation. These showed positive and significant correlation with P uptake for eight out of the ten soils. The relative values of q were higher for the soils which had lower values of supply parameter.