Measures to maintain, or improve, biodiversity are mainly related to areas excluded from agricultural use. Such uncultivated areas are prone to invasive species encroachment.
The treatment that is recommended to maintain the desired biodiversity is to mow them once a year or once every few years, depending on the type of community. Sometimes extensive livestock grazing is an appropriate form of their maintenance. Also, edge zones of cultivated fields, baulks, where herbicide spraying is not applied, can provide habitat for weed species traditionally found in this environment. Among these are a number of species threatened with extinction due to agricultural intensification. Leaving up to 3 m unsprayed zones at field edges is an effective method of protecting these species at a relatively low cost of agricultural production. Another habitat important for maintaining biodiversity is mid-field thickets and shrubs – sometimes referred to as ‘boles’- i.e. groups of trees, or sometimes single old trees growing on baulks and roadsides. Such places in the open agricultural landscape provide habitat for many species of insects, birds and sometimes bats. The creation of new habitats for naturally occurring plant and animal species and the maintenance of existing habitats in a suitable condition is a prerequisite for maintaining biodiversity in agricultural areas. In addition to the hitherto well-known positive protective effects of trees in the agricultural landscape in terms of reducing wind velocity and thus soil erosion, the reduction of evaporation, which has the beneficial effect of reducing water loss from the soil, is becoming increasingly important in view of the scarcity of precipitation. This increases soil microbial activity and soil biodiversity.