A B S T R A C TWe collaborate with the Chinese Ministry of Agriculture (MOA) and conduct a randomized controlled trial (RCT) to examine the effects of farmer field schools (FFS) on the knowledge acquisition by farmers in rice production in Anhui, China. The intensification of China's agricultural production has raised widespread environmental concerns. Lack of advisory services to increase awareness and knowledge has been found to be the primary constraint to improving farming and environmental outcomes. However, training millions of small farmers is a significant challenge. To impart the knowledge of sustainable and low-carbon farm management, the MOA recently piloted a FFS program through its public extension system. A participatory approach to rural advisory services, FFS was initiated by the Food and Agriculture Organization during the late 1980s in Asia, and at present is being practiced in more than 90 developing countries. However, the effectiveness of the FFS program has not been conclusively demonstrated, and the results of previous impact evaluations have varied greatly according to evaluation methods. A major drawback of previous studies has been selective participation in the program, leading to biased estimates of program effects. We use an RCT to overcome these problems. The results are heterogeneous: FFS effectively improved farmers' knowledge of pest management and agro-environment; however, we find no effects on nutrient management and cultivation knowledge. Furthermore, the effects were smaller for female and old participants. Being a "best-design" approach of agricultural extension initiated by FAO, FFS faces challenges to be "best-fit" in China, where urbanization and agricultural transformation are emerging.

About 3ieThe International Initiative for Impact Evaluation (3ie) is an international grant-making NGO promoting evidence-informed development policies and programmes. We are the global leader in funding and producing high-quality evidence of what works, how, why and at what cost. We believe that better and policy-relevant evidence will make development more effective and improve people's lives. 3ie Impact Evaluations3ie-supported impact evaluations assess the difference a development intervention has made to social and economic outcomes. 3ie is committed to funding rigorous evaluations that include a theory-based design, use the most appropriate mix of methods to capture outcomes and are useful in complex development contexts. About this report3ie accepted the final version of this report as partial fulfilment of requirements under grant OW3.1216 issued under Open Window 3. The content has been copyedited and formatted for publication by 3ie. Due to unavoidable constraints at the time of publication, a few of the tables or figures may be less than optimal. All of the content is the sole responsibility of the authors and does not represent the opinions of 3ie, its donors or its Board of Commissioners. Any errors and omissions are also the sole responsibility of the authors. All affiliations of the authors listed in the title page are those that were in effect at the time the report was accepted. Any comments or queries should be directed to the corresponding author, Krishna B Kumar at kumar@rand.org Funding for this impact evaluation was provided by 3ie's donors, which include UKaid, the Bill & Melinda Gates Foundation, Hewlett Foundation and 12 other 3ie members that provide institutional support. A complete listing is provided on the 3ie website at http://www.3ieimpact.org/en/about/3ie-affiliates/3ie-members/ Suggested citation: Burger, N, Fu, M, Gu, K, Jia, X, Kumar, KB and Mingliang, G, 2015 ii AbstractIn China, a major agricultural challenge is the sub-optimal use of fertilizer and the environmental effects associated with overuse. The Chinese Ministry of Agriculture (MoA) is addressing this problem by instituting farmer field schools (FFS), but this initiative has not been rigorously evaluated. We used a randomised controlled trial to evaluate the FFS program in five counties in Anhui and Hebei provinces, for rice and tomato crops, respectively. We used a matched pair random assignment of villages into treatment and control groups, and we randomized additional farmers into an 'exposed' group to study diffusion effects. We found no significant effects of the FFS intervention on mean fertilizer use for either crop. However, we found that fertilizer usage is highly heterogeneous, and a simple comparison of means masks the differential response to the FFS programme at either end of the distribution. For rice farmers, the percentage increase in nitrogen fertilizer usage at the lowest quintile is significantly higher for the treatment group than that for the control group, with a less pronounced drop in usage in...