David MengelDr. David Mengel is a recently retired, Professor Emeritus of Agronomy at Kansas State University. He remains active in retirement doing research and extension programs and operating a 150 hectare family farm, where he currently produces both grain nd forage sorghum. A Certified Professional Soil Scientist and Certified Crop Advisor, he has over 40 years professional experience and is recognized as an authority on soil fertility and nutrient management. Read More Read Less