VARIATION OF THE PARAMETERS OF HARMFUL ACIDITY IN ERODED CINNAMON FOREST SOILS (CHROMIC LUVISOLS) AND ITS RELATION WITH THE SOIL HETEROGENEITY
Published in AgroLife Scientific Journal, Vol. II, Number 1
Written by Stefka TODOROVA, Krasimir TRENDAFILOV
In this study, the soil acidity is characterized by pH, and content of exchangeable Al3+, H+and Mn2+. It is established the content of exchangeable ions, with neutralizing in respect to harmful acidity effect - exchangeable Ca2+ and Mg2+. On the basis of the results is calculated the degree of saturation of the permanent sorption positions in soil with easily mobile bases V3%. The latter is used as a quality criterion for characterizing the degree of need of liming of soil. The amount of neutralizing lime material is calculated based on the content of easily mobile Al3+, H+and Mn2+ in meq/100g soil. Overcoming the heterogeneity of soil, as regards to the need and rates of liming is done by application of method for geospatialization based on the distribution of sampling points in graticule. The data for eroded cinnamon forest soil show that relatively greatest variation in soil acidity is found in the most eroded areas. In them is more pronounced spatial heterogeneity of soil in respect to easily mobile exchangeable Al3+, H+and Mn2+, while as regards to the contents of easily mobile bases - Ca2+ and Mg2+eroded areas are relatively homogenous. Relatively greatest need of liming, based on the degree of base saturation is observed in average eroded soils, mainly in areas where illuvial clay issettled on the surface and forms relatively deep layer. Application of this ameliorative concept to full neutralization of the harmful Al3+ and part of the H+ and Mn2+ led to calculation of high rates of neutralization meliorants up to 6000 kg/ha.