Farming and fertilizers: how ecological practices can make a difference: Agriculture involves a difficult balance between food production and environmental impact. For example, fertilizers can help to achieve good crop yields, but over-using them produces greenhouse gas emissions and pollution. Some of these impacts also threaten future agricultural production. Greenhouse gas emissions, for instance, contribute to climate change and increase the likelihood of extreme weather events.
To sustain agriculture, then, it is necessary to minimize the use of inputs like fertilizers, and support crop growth in other ways. One approach is through increasing ecological functioning within farms. This means enhancing relationships between different on-farm organisms, including crops, livestock, microbes, and wild plants and animals. Using these relationships to support crop yields is called “ecological intensification”.
Previous research has shown that ecological intensification can be effective. But studies have only been done over short timescales of just a few years, whereas the effects of agricultural practices often take longer to become clear. Variation in weather between years can obscure effects in the short term, and some ecological processes take several years to stabilize.
In a recent study, my colleagues and I explored whether long-term studies also support ecological intensification. To answer this, we sought out 30 long-term experiments from around Europe and Africa. We used these experiments to look at whether ecological intensification could reduce the need for two inputs: nitrogen fertilizer and tillage. We found that ecological intensification can partly replace fertilizers to support crop yields, because both ecological intensification and fertilizers increase soil nutrients. So farmers could use ecological intensification to reduce fertilizer use while maintaining the same yields. Farmers who already used low or no fertilizer could increase their yields.