Replacing synthetic fertilizer by manure requires adjusted technology and incentives: A farm survey across China

Improved recycling of animal manure may contribute to reduce synthetic fertilizer use in cropland, thereby to mitigate environmental and human health threats. However, the potential impacts of such strategies are not well-quantified, and the socioeconomic-cultural barriers are not well-understood, which limit the effectiveness of policy measures, especially in rapidly developing countries. We used a combination of scenario analyses and a farm survey among 1500 farmers across China to explore the impacts of replacing fertilizer by manure and to assess the existence of possible technical, socioeconomic, cultural barriers. We estimated the use of nitrogen fertilizer may be reduced by 3 to 32%, via increased manure recycling from 30% in 2015 to 34 to 70% in 2050, depending on fertilization measures and cropping system. However, only 55% of the interviewed farmers actually used manures. Eight out of 38 factors were evaluated as key barriers to manure use, which involved in the perceived high economic costs of manure use, lack of suitable application technology, and unknown manure quality and availability. Cereal farmers perceived greater barriers than cash crop growers. Several key actions have to be prioritized to achieve the high reduction in fertilizer use. There is need for a transparent manure exchange market, with manure-use advisors, accurate information on the composition and price of manure products, middle man for transporting manure from specialized livestock farms and distant crop farms, and contractors with manure application machinery. This requires specific policy incentives and outreach and control strategies.