IMPACT OF FERTILIZATION ON AGROFORESTRY SYSTEM COMBINING ROWS OF WILD CHERRY AND SMALL-LEAVED LIME WITH PERENNIAL GRASSES AND LEGUMES IN LATVIA

Abstract

Interest in agroforestry as land use practice continues to revive due to it's social, economic, and especially environmental and climate change mitigation benefits. This article encompasses results of productivity of hemiboreal agroforestry system combining rows of wild cherry and small-leaved lime with perennial grasses (Phalaris arundinacea L. and Festulolium pabulare) and legumes (Galega orientalis Lam.). Experimental plot of agroforestry system was established in agricultural land on mineral soil in central part of Latvia in the spring of 2011. Different fertilizers such as by-products of bioenergy production (wood ash, digestate), municipal waste (wastewater sludge) and mineral fertilizers were used to compensate nutrients in the soil and soil buffer capacity. Survival rate of the trees (especially for wild cherry) in agroforestry systems was relatively very low, mostly due to winter frosts and later browsing by hares. Nevertheless, results of our study highlighted that both used fertilizers and interactions between trees and herbaceous plants impact total productivity of system including tree growth, yields of biomass and seeds of herbaceous plants as well as chemical composition of biomass of herbaceous plants. Whereas obtained biomass of herbaceous plants can be used for both forage and energy production purposes, the benefits and risks of fertilization must be assessed on a case-by-case basis depending on the intended use of biomass.