Acid phosphatase activity under the impact of erosion level in agricultural soils of different type and land use

Kostadinka Nedyalkova, Radka Donkova and Iliya Malinov

Abstract: The suitability of soil enzyme activities as early and sensitive indicators of changes in soil status due to soil disturbances has been extensively studied. Little is known about the impact of soil erosion level. The aim of the work was to study changes in acid phosphatase activity depending on the degree of water erosion, soil type and land-use practices and to find out the relationships with chemical and physical soil properties. Samples from three soil types (Luvisol, Vertisol and Cambisol) of different land use (undisturbed, arable, abandoned and long fallow) and different degree of water erosion (slight, moderate or severe) were investigated. It was found that acid phosphatase activity varied between 1.69–6.69 μmol pNP.g-1.h-1 among studied soils. There was an evidence of negative influence of erosion gradient on the phosphatase activity. Depending on the land use, the activity was arranged in the row: undisturbed=arable> abandoned>fallow. Soil type effect was significant in the order Vertisol = Luvisol > Cambisol. Data pointed on stronger impact of soil type than land-use practices. For all soils, acid phosphatase activity was positively correlated with soil silt, clay and pH, and negatively correlated with soil sand content. Negative relations of erosion gradient with silt, clay, total organic carbon and total nitrogen contents for all soil types were established. The results obtained could contribute to establishment of soil degradation processes indicators and to soil quality monitoring.

Keywords: acid phosphatase activity; degree of erosion; eroded soil; land use

Date published: 2021-02-17