Investigations on Fertigation of Peach on Three Soil Types - Patterns of Soil Wetting

KOUMANOY K., D. DOCHEV and G. STOILOY 1998. Investigations on fertigation of peach on three soil types - patterns of soil wetting. Bulg. J. Agric. Sci.,4:745-753 The results presented in this article are part of a larger investigation aimed at clarifuing of fertilizers' migration and localization in the root zone ofarborescent ffuit plants under fenigation, predicting the eco- lo-eical consequences of applying this method of fertilization. and verification of the currently used appli- cation ratcs- The experiment rvas carried.out in lysimeters'on three soil types: alluvial-meadow soil (Fluvisol) - sandy loam, ciniramon-forest soil (Luvisol) - clay loam, and smolnitsa (V-ertisol) - clay. Single peach trees, grown in every lysimeter *.ere drip-irrigated by single drippers rvith discharge of 4.6 l/tr and located at 0.75m from the trunk. The fertilizers - urea (CO(NH:):) and phosphoric acid (H.POJ, rvere supplied through the irrigation system, the annual amounts being partitioned to monthly doses. Investigation results rvere based on soil analyses, analyses oflysimetric waters, and electromenical readings (gypsum blocks). It u,as found that in soil types with diffarent hydraulic characteristics the same irrigation regime result- ed in essentially different patterns of soil u'ctting- Root activity n as also proven to play a substantial role in the irrigation water redistribution into the soil volume. The application efficiency proved to be closely related to the hydraulic conductivity ofthe soil and varied considerably between soil types. Invcstigation results suggested the need of changing the method- ology for schcduling and management of localized (drip/trickle) irrigation.