Francesca Cotrufo, Colorado State University скачать в хорошем качестве

Francesca Cotrufo, Colorado State University

Can perennialization and diversification solve the soil C dilemma? Keynote talk by Francesca Cotrufo, Colorado State University at the conference "Is the Future of Agriculture perennial?", Lund University, May 2019. To feed the growing world population we need to regenerate and sustain the health of our agricultural soils. Healthy soils, by definition, are able to support productivity through nutrient recycling, water retention, and increased organic matter content. The accrual of soil carbon (C) while maintaining nutrient recycling is not an easy task, since it requires that crop inputs and other organic amendments are processed by microbes, assuring the mineralization of nutrients, while the C is efficiently stored in persistent organic matter fractions. Henry Janzen elegantly presented this issue as the “soil C dilemma”. We propose that increasing and maintaining consistent crop inputs through time in particular via the root system along the soil profile with perennialization will promote C accrual both by the increased addition of crop residues and root exudates, and by maintaining a connected microbial community. This, in conjunction with diversification through the addition of a legume to the cropping system, will maintain a diverse microbial community, promoting co-metabolic activities and the recycling of soil organic matter to provide fertility. We have started testing this hypothesis using dual, 15N and 13C labeled residues to trace their fate in cropping systems with different degree of diversification, perennialization and diversification and will present concepts and preliminary results.