Of the many things we might often overlook, soil is perhaps the most important. Fertility in soil - or the lack thereof - has direct ties with the food that we eat and the nutrients we receive. With the advancement of technology and the Green Revolution, many countries experienced a huge growth in soil fertility and food security over the past century. However, soils in Africa did not reap much of the benefits of the Green Revolution, which completely bypassed Africa and left little conservation efforts there. Soils, agroecology and socioeconomic situation in Africa pose specific constraints to crop productivity that needs to be addressed; just by knowing U.S. agriculture, we cannot transform the soils in Africa. We need to not only utilize the scarce resources in the African farms, but also strategize creative solutions for the small farm holders to meet the needs of their soil conditions. Dr. Johannes Lehmann, Professor of Soil Science at Cornell University, therefore develops simple strategies to improve soil health for all farmers in a sustainable way, not only in the U.S. but also in Africa, in order to increase food security and alleviate poverty.

Collaborating closely with nongovernmental organizations and development agencies, Dr. Lehmann works with an interdisciplinary team of experts in economics, sociology, and engineering who study the basic principles and applied solutions of how organic matter and nutrients in soil work, how to increase them, and how to avoid losing organic matter and nutrients. The roadmap that these teams develop are reflective of priorities by local organizations which allows to ‘test-drive’ it under real-life scenarios. Throughout his research, Dr. Lehmann has experienced how important organic carbon in soil is to provide lasting soil fertility, mitigate nutrient pollution, and decrease greenhouse gas emissions. He has also learned that if strategies in developing countries are to work, they have to be as clever as they have to be simple and involve other sectors such as bioenergy and waste recycling from urban areas. Therefore, Dr. Lehmann and his team work across scales from small to large, starting with the nature and creation of soil organic matter on an atomic level, how organic molecules are stabilized on clays or processed by microorganisms using one-of-a-kind, high-resolution microscopes, to field studies on farms and to predicting the outcome of land use decisions on food security and climate at a global scale. Ultimately, Dr. Lehmann hopes to benefit both the people and our environment by improving soil health. Some of the team’s research materials involve: molecular techniques, isotope tracing approaches, x-ray and IR microscopy, greenhouse studies, field experiments, watershed and stream observations, as well as regional and global modeling.

Dr. Lehmann’s current areas of focus include:

• Soil Fertility: Dr. Lehmann and team are specifically addressing soil sustainability by managing soil organic matter including biochar, compost, and manures. The team’s previous investigation into the organic carbon that is left behind by fires has shown that this charcoal has a remarkable ability to improve soil health for the long-term. Especially evident in the so-called Terra Preta soils, or dark soils made by Amerindian populations in the Amazon before the arrival of Europeans, charcoal can retain soil fertility over several millennia. This tremendous success the team has learned of in South America, particularly in Brazil whose conservation agriculture efforts have named it the #1 producer of soybean, corn, and cotton in the world, unfortunately has so far not worked in Africa. Seeking a different roadmap and approaches in Africa from those taken in Asia and Central and South America where other tactics have worked, Dr. Lehmann has implemented the modern application of what is known as "biochar," or charcoal used for soil improvement. Biochar has since stimulated a new area of soil research, linking bioenergy production, waste management and carbon sequestration with soil fertility, and Dr. Lehmann now investigates the molecular properties of the biochar, its effects on soil microorganisms, soil carbon cycling, greenhouse gas emissions, nutrient availability and leaching. Ultimately, Dr. Lehmann hopes to understand the fundamentals of these soil fertility management techniques and use their practical application in the Sub-Saharan Africa.

• Waste Management: Often waste that has very valuable nutrients and carbon is being flushed down the toilet. Therefore, recycling nutrients to produce fertilizers (waste-to-value) will reduce wastes and bring nutrients to the farms that need it most. Dr. Lehmann and his team are developing innovative fertilizers from waste, utilizing not only human waste from modern toilets but also waste from agriculture and slaughterhouses to produce phosphorous fertilizers in Ethiopia. In landlocked countries in Africa where fertilizers are ironically many times more expensive than in the U.S., these locally made fertilizers, less expensive to produce, will perform as well as imported fertilizers at a price point nationally available in the region. Investigating opportunities to recycle nutrients from toilets in the slums of Nairobi and slaughterhouses in Ethiopia will allow the team to produce inexpensive yet effective fertilizers where they are needed most, while mitigating the environmental burden of human and animal wastes.

• Food Security: Dr. Lehmann and his team do a great deal of interdisciplinary research connecting different strategies of addressing food security issues in collaboration with nongovernmental organizations and local research organizations. Studying food security issues in relation to climate change, the team is able to mark agricultural approaches and recognize monumental challenges that face agricultural development in Sub-Saharan Africa. Connecting different sectors such as energy with agriculture, the team investigates ways to implement bioenergy plants in Kenya that will return carbon back to soil while generating fuels and energy. The team is also expanding their toolbox to make more out of scarce resources from small farm holders. By implementing practical applications, Dr. Lehmann hopes to increase crop productivity and thus alleviate poverty globally.