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