Maintenance of Phosphorus Fertilizer and Residual Phosphorus Effect on Corn Production

Hayriye Ibrikci, Janine Ryan, Ahmet Can Ulger, Gokhan Buyuk, Berk Çakır, Kursat Korkmaz, Ebru Karnez, G. Ozgenturk, O. Konuskan. (1/7/2005). Maintenance of Phosphorus Fertilizer and Residual Phosphorus Effect on Corn Production. Nutrient Cycling in Agroecosystems, 73 (3), pp. 279-286.

Abstract

Phosphorus (P) deficiency is invariably a common crop growth and yield-limiting factor in unfertilized soils, especially soils high in calcium carbonate, which reduces P solubility. Even when such soils are fertilized, adsorption and desorption lead towards a reversion to stable and less soluble P forms, thus reducing fertilizer use efficiency. Field trials that examine the implications of such P reactions and residual fertilizer P responses in the field are relatively rare in Mediterranean environments. A 5-year field experiment in southern Turkey examined the residual effects of repeated P fertilizer applications for corn production in a calcareous soil Typic Xerofluvent. Following the initial year's fertilization (0, 33, 66 and 99 kg P ha−1) to establish a range of soil P levels in subsequent years, the main plots received 0, 9, 18, 27 and 36 kg P ha−1 annually. Grain P uptake was calculated for each year and used in the prediction of P recovery. All plots were sampled and analyzed for available P prior to planting with a local corn hybrid. Soil P values increased with the initial P levels (8–24 mg kg−1) but declined after 3 years (6–10 mg kg−1). Only the lowest annual P application rate (9 kg P ha−1) produced an available P level that was not in the sufficiency range. Grain yields across the main and subplots and years ranged from 6.6 to 13.2 t ha−1. Overall corn yield averaged over the years increased by 8–33% compared to the control as the rates of applied P increased. However, P application had no effect in a year when below-average rainfall restricted crop growth. A residual P effect on grain yield occurred with higher P application levels in the last year. Leaf and grain P concentrations were in the sufficiency range in general. Grain P uptake was calculated for each year and used in the prediction of P recovery. Actual recovery was higher with low P application rates and ranged between 10.8 and 46.4%. The study indicated that under irrigated conditions, corn is likely to respond to P fertilization, but that buildup of available P can occur within a few years and adequate plant available P levels can be maintained by modest P fertilizer application rates.