Investigation on Fertigation of Peach on Three Soils.
III. Zones of Salt Accumulation
K. KOUMANOV, G. STOILOV and D. DOCHEV
Institute of Fruit-Growing, BG-4004 Plovdiv, Bulgaria
KOUMANOV, K., G. STOILOV and D. DOCHEV, 1999. Investigations on fertigation on three soils – zones of salt accumulation. Bulg. J. Agric. Sci., 5: 725-730
The experiment was carried out in lysimeters on three soils: 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 applied by the irrigation water amounts of urea and phosphoric acid did not enhanced salt concentrations in the soil solution to unfavorable for the plants values.
The zones of salt accumulation coincided (by location, shape, and size) with the areas of increased nitrate content. Based on a strong correlation, it was derived a regression equation which allowed the concentrations of nitrate nitrogen in non-saline soils to be determined from the soil electrical conductivity, independently on the soil type and with a satisfying for practical purposes exactness.
Key words: drip-irrigation, fertigation, lysimeters, peach, soil electrical conductivity, nitrates