Linking land use and peat soil distribution and properties in agricultural lands of Latvia

Abstract

Agricultural practice on peat soils represents an explicit tradeoff between carbon sequestration and farmland productivity, i.e., peat soils are a pool of carbon and a fragile component of biodiversity but also highly productive farmland. Agricultural land use and land-use change can have a significant impact on peat soil distribution and properties.This study aims to clarify the distribution of various agricultural land uses in peat soils and to analyse potential drivers of the distribution patterns. The presented research is based on the case studies of agricultural activities in peatlands in substantial landscape locations – a) lowland polder in the ancient coastal lagoon; b) drained inland wetland (inland polder); c) marginal upland landscape; d) undulated plains in a mosaic landscape.Our study shows that peatland distribution has reasonably impacted agricultural land use and its intensity, however in different landscapes, it reveals differently. In coastal lowland polders, due to intense agricultural use, peat soils have significant mineralization levels; in inland polders, the mineralisation is more decelerated; in upland and mosaic landscapes the peat soils have faced farmland abandonment. Mineralization of peat depends on plowing, which promotes it, as well as impacts the thickness of the peat layer. If the peat layer is thinner, the faster the loss of organic matter occurs. Peat soils determine the current use of the land. In the depressions of the undulated topography there are land abandonment and overgrowing by bushes, while polder soils are intensively used by plowing. The presented results provide additional criteria for decision support in agricultural land-use planning, i.e., the implication of agri-environmental schemes in agricultural lands on peat soils.