Can mulching or composting be applied to maintain semi-natural grassland managed for biodiversity?

Abstract

Traditional, extensive management systems in grasslands have played a fundamental role in the formation, maintenance and conservation of grassland of high natural value. Contemporary processes in the agricultural economy make this type of management unprofitable. Simplified management systems are implemented as part of agricultural and environmental programmes and in protected areas, but these can cause changes in botanical composition. An experiment was conducted for six years on grassland in the Carpathian Mountains to compare mulching and compost application with late cutting and biomass removal. In the conditions of mountain grassland of medium fertility, the level of biomass and the species composition of the vegetation were the same following mulching as in the case of cutting and biomass removal. Mulching was only found to affect the temperature of the topsoil. Compost application caused a significant increase in the amount of biomass. The species composition was the same as for the other management types, but there were changes in the proportions of individual species and functional groups. High grasses were dominant, while the proportion of legume plants was small. Moreover, the N:P ratio was lower following the use of compost, indicating a shift from P limitation to N limitation. Mulching can be used as a simplified means of management in the case of certain types of grassland communities, but its effects must be monitored. Compost application would necessitate modification of other elements of management, e.g. increased frequency of cutting.