Loss of biodiversity on fields

Plant protection products threaten farmland birds

LercheClick to enlarge
Plant protection products threaten farmland birds such as the skylark
Source: Dubultz / Fotolia.com

The extensive use of plant protection products in agriculture is causing increasing harm to birds on fields. This is the conclusion reached in a study done on behalf of the Federal Environment Agency The partridge and skylark in particular are finding less food because, besides killing pests, the chemicals used also kill prey such as butterfly caterpillars and other insects. In addition, herbicides eliminate wild arable plants which insects depend on from the fields. The result is permanent disruption of the food web. It is possible however to protect biodiversity on fields and grassland. "We need a certain land area where no plant protection agents are spread. Farmland birds, butterflies and bees would then find enough nutrition on such flowering strips and fallow land."

The researchers for the UBA study evaluated a great deal of existing research on the vulnerability of the populations of 27 bird and 22 mammal species. They wanted to determine the causes of the biodiversity loss observed in many areas. The use of an insecticide often means death by starvation for the young and endangerment of the species of farmland birds in particular, which depend on the insects found on fields to rear their young. In the cases of the partridge, the goldhammer and skylark, these indirect effects of plant protection products have largely been scientifically proven. All species of ground nesting birds also suffer as a result of the use of fungicides which allow crops to be planted ever more closely together, leaving too little room and food for birds to raise their young.

Compensatory measures are needed since a complete ban on chemical plant protection agents is incompatible with intensive agriculture. "Flowering strips, fallow land and low density seeding can also do their bit to protect biodiversity on fields in the age of modern, intensive agriculture. Many of these practices are already part of the agri-environmental programmes of the German Federal States, and therefore we have gained good experience with them in terms of practicability and effectiveness. The negative effects of plant protection products can thus be reduced considerably, without jeopardising crop yields," said Thomas Holzmann.
In any case efforts for the long term must work to reduce the dependency of the agricultural sector on the use of pesticides. This is also the clearly defined aim of the EU Framework Directive on the Sustainable Use of Pesticides which Member States must achieve. Organic farming practices are already proving that it is possible to do largely without chemical plant protection products. Organic farming in Germany has had a land area of only 6 per cent up to now – thereby failing to meet the target of the national sustainability strategy of at least 20 per cent for organic farming. “We can and must make a greater effort in this regard,” said Mr Holzmann.


Some 100,000 tonnes of plant protection agents are spread on fields, grassland, vineyards and orchards in Germany every year. The chemicals are subject to a strict authorisation procedure in which the UBA is also involved. Plant protection agents may only be used in compliance with good agricultural practice and may not cause any unacceptable effects on biodiversity. The UBA does an extensive analysis of the environmental risks of a plant protection agent before it is approved, and it issues recommendations for risk management.

Umweltbundesamt Headquarters

Wörlitzer Platz 1
06844 Dessau-Roßlau