Investigations on Fertigation of Peach on Three Soils II. Migration and Localization of Phosphorus

G. STOILOV, D. DOCHEV and K. KOUMANOV

Institute of Fruit-Growing, BG-4004 Plovdiv, Bulgaria

Abstract

STOILOV, G., D. DOCHEV and K. KOUMANOV, 1999. Investigations on fertigation on three soils. II. Migration and localization of phosphorus. Bulg. J. Agric. Sci., 5: 615-620

The experiment was carried out in lysimeters on three soil types: alluvial-meadow soil (Fluvisol) sandy loam, cinnamon-forest soil (Luvisol) clay loam, and smolnitsa (Vertisol) clay. The fertilizers urea [CO(NH2)2] and phosphoric acid (H3PO4), were supplied through the irrigation system, the annual amounts being partitioned to monthly doses.
It was found that, the application of phosphoric acid (H3PO4) through the systems for micro-irrigation increased considerably the migration ability of phosphorus, compared to traditional methods of fertigation and irrigation. The mobile phosphorus was distributed concentrically with maximal concentrations under the point of dripping, despite the pattern of wetting, the root activity, or the soil type. Forming a significantly deep zone with high content of available phosphorus and with a favorable soil moisture, the fertigation proved to provide optimal conditions for supplying of the fruit-tree species with phosphorus and for increasing the effectiveness of the phosphorus-fertilization.

Key words: drip-irrigation, fertigation, phosphoric acid, lysimeters, peach