What is it?
Pesticides are used in agriculture and horticulture to limit crop damage caused by gnawing lice, by caterpillars and by diseases (fungi and bacteria). The problem is that the pesticides also find their way into soil and water, and then pose a risk to the environment and public health. An alternative is to use natural enemies, like lady-birds and wasps, which eat the pests or act as parasites. Pests can also be infected. Microorganisms (bacteria or fungi) in the soil can thus help to control pests.
Sustainability
Insects needed to control pests the natural way rely greatly on green infrastructure and nature areas in the immediate vicinity of crop fields. Besides the pests in the field that serve as their food, insects require florid vegetation to gather nectar, pollen and other prey animals. Rising vegetation (like hedgerows and farmland plants) provide sheltered spots for hibernation. Many insects are only able to cover small distances, so these landscape elements must form a joined-up network around the crop fields. It is also important to manage these perimeters and adjacent parcels of land sustainably.
In real life
Creating florid field borders and hedgerows is conducive to pest control. The restoration and natural management of structures already present in arable farming areas (ditch edges, soft shoulders and farmyards) will give the pest-controlling organisms a helping hand. Natural elements are frequently usable for multiple purposes. For example, in the Hoekse Waard region in South Holland province, ditch edges have been configured to serve as a buffer strip for water purification in a Functional Agro-Biodiversity (FAB) project. The ditch edges are being adapted to make them suitable for pest-controlling insects and for farmland birds: doing more with less!