Improving climate protection in agriculture

Technische Universität München: Agriculture is responsible for around ten to twelve percent of all greenhouse gases attributable to human activities. This raises the question of how these emissions could be reduced. A recent study has investigated – for the first time – the full range of factors that contribute to greenhouse gas emissions, namely soil and climate conditions, the agricultural model and the farming intensity on both organic and conventional holdings. The study has enabled scientists to develop a new model that will allow agricultural landholders to determine and improve their climate balance.

As part of the study, scientists investigated 40 organic and 40 conventional agricultural holdings across Germany’s four agricultural regions. They focused exclusively on crop and dairy farms. The scientists recorded all relevant climate gas streams during the entire production process, including methane, nitrous oxide and carbon dioxide. In the case of dairy farms, they also factored in the purchase of soybean meal from South America and all related greenhouse gas emissions.

..."There are different ways of improving a farm’s climate balance," explains Professor Kurt-Jürgen Hülsbergen from Technische Universität München (TUM). “One effective strategy is for landholders to grow feed themselves rather than purchase soy from another source. Farms can also streamline production processes and deploy modern technology to obtain higher yields without increasing the amount of energy required.”

In crop farming, increasing nitrogen efficiency is a key factor. High levels of nitrous oxide are released into the environment if crops are unable to utilize all of the nitrogen fertilizer that was spread. The production of nitrogen fertilizer is also energy intensive, which further increases the climate balance of unused nitrogen.

In contrast, the greenhouse gas CO2 can be stored long term as humus in the soil, and thus eliminated from the climate balance. “This can be achieved by planting legumes as part of a diversified crop rotation strategy,” explains Professor Gerold Rahmann at the Thünen Institute. “Using soil less intensively and applying organic fertilizer also helps.”

Organic farming is more energy efficient and produces less land-specific CO2 emissions. This advantage, however, is offset by the significantly lower yields achieved through organic farming practices. The pilot organic crop farms produce around twenty percent less emissions per yield unit than conventional holdings....

A farm near Cuxhaven, shot by Martina Nolte, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Germany license.