Effect of acidic rhizosphere fertilizer on the soil pH and Fe availability of calcareous soil

A diffusion experiment and pot trial were conducted to evaluate the effect of acidic rhizosphere fertilizer on the soil pH and Fe availability and the growth, iron deficiency correction of peanut on calcareous soil. The results indicate that application of acidic fertilizer with pH 1-2 decreased the soil pH within 6cm from application point due to the diffusing of H+ from the acidic fertilizer in incubation period of 4 weeks. The extent of pH changes reached 0.9 unit and soil DTPA extractable iron concentration increased by 5.9 mg/kg with 2cm diameter of fertilizer. Results also indicated that acidic fertilizer application increased in the chlorophyll SPAD value, active Fe concentration in peanuts leaves and the total amount of Fe uptake. Therefore, the acidic rhizosphere fertilizer was efficient in correcting iron chlorosis on the calcareous soil in this experiment.