publication PARI Policy Brief No. 13: How to Keep Tractors Running in Africa? This policy brief presents some answers based on a comprehensive study on the knowledge and skill requirements for machinery owners and operators in Zambia Published: 2019 Download Policy Brief (0.2 MB) Available here in English and here in German. This Policy Brief is based on Thoelen, Jan (2018). New approaches to training and education in sustainable agricultural mechanization for emerging farmers in Zambia. Master thesis. University Hohenheim.