Organic farming focuses on maintaining soil fertility and biodiversity. But for an insect-friendly future, the whole farm landscape will have to change.
Compared with conventional agriculture, organic farming has clear advantages for insects and for biodiversity in general. A 2015 study related to the EU Biodiversity Strategy found that organic farms generally have 30 percent higher species richness and 50 percent higher abundance of organisms than conventional farms. A study from Germany summarizing many individual investigations found that 23 percent more insect species that visit ﬂowers were present on organically farmed ﬁelds than on those subject to conventional management.
The organic ﬁelds had an average of 30 percent more types of wild bees and 18 percent more butterﬂy species. Organically managed land not only had a greater diversity of insects, it also had more insects in total. On average there are 26 percent more ﬂower-visitors and almost 60 percent
more butterﬂies on organic ﬁelds. Farmland birds are commonly used as indicators of biodiversity and of insects.
A 2010 EU wide study showed a higher number of farmland birds on organic farms than on conventional farms. Recent data from Germany indicate that there were 35 percent more such bird species on organically managed land, and they were 24 percent more numerous in terms of population. Overall, there has been a decrease in bird species that feed on small insects and spiders during the breeding season in Germany in recent years.
Scientists attribute this to a lack of food in conventionally managed ﬁelds and to the widespread use of insecticides. Organic farming has a positive effect on biodiversity and on insects for various reasons. It avoids using synthetic pesticides that conventionally managed farms apply to control weeds and pests. Instead, it removes weeds mechanically, or controls them by rotating and switching crop types each season.
Organic farms also do not use artiﬁcial nitrogen fertilizer. Instead, they sow clover, lucerne or lupins. These plants ﬁx nitrogen in the soil and therefore make a good green manure. At the same time they provide insects with both food and habitat. The German metastudy found that the number of wild plant species on organically farmed ﬁelds averaged 94 percent higher than on conventional ﬁelds, and 21 percent more plant species were found in the ﬁeld margins.
In cereal growing, the effects of organic farming on biodiversity are far-reaching because conventionally grown grain relies on heavy applications of mineral fertilizers and pesticides. Pollinators are very sensitive to pesticides. Because organic farms abstain from using chemicals, local pollinators become more abundant. But since pesticides may drift with the wind, and insects naturally visit conventionally managed farms nearby, the negative effects of pesticides may overshadow the positive ones.
This may also be true if hedges, ﬂowering ﬁeld margins and other ecological niches are missing. Overall, though, organic farming has a bigger positive effect on insect numbers if the surrounding area is monotonous: i.e., if it has few variegated landscape elements and is only covered with a single type of crop. Critics argue that the lower yields of organic farming would make it necessary to expand the area of cultivated land worldwide by converting previously unused land that is high in biodiversity.
This would make the net effect of organic farming negative, because uncultivated land has greater biodiversity than organically managed ﬁelds. Such criticism is justiﬁed in that, in temperate latitudes, yields from organic farming are lower than those from conventional farms. Nature would beneﬁt from 100 percent organic farming only if land is saved through lower meat consumption and if food losses are reduced. The production of 327 million tonnes of meat a year, the world’s current consumption, takes up almost 80 percent of the global agricultural area.
Therefore, lower meat consumption is of central importance to sustainable land management. Organic farming has so far been a niche business in many developed and emerging countries. Worldwide, it covers only 1.5 percent of the agricultural area; in the European Union the ﬁgure is 7 percent – though it is growing quickly.
Major differences exist among the EU’s members: in Malta, organic farmland covers a minuscule 0.4 percent of the total, while in Austria it accounts for over 23 percent. These ﬁgures only include areas that are certiﬁed as organic. But many farms worldwide follow the basic principles of organic farming: maintenance of soil fertility, the cycle of soil–plants–animals and humans, and farms’ independence from external inputs such as fodder and synthetic fertilizer.
Few of these farms are certiﬁed as organic. The broader concept known as “agroecology” is promoted by many civil society organizations around the world, along with international organizations such as the Food and Agriculture Organization of the United Nations. They all support the ecological and social restructuring of the agricultural and food system, including marketing and power structures – thus promoting an insect-friendly future.