Microbial ecology of soil and manure

Microorganisms are important for crop production as well as the environment. Bacteria, fungi and other microbes decompose organic matter from e.g. crop residues and manure, releasing nutrients to the soil, and nutrients in fertilisers are transformed. As a result of the microbial activity, solutes and and gases may be lost to the aquatic environment and atmosphere. 

A basic understanding of microbial processes and their interaction with the soil environment makes it possible to adjust a cropping system so that nutrients are primarily released to the soil in periods with plant growth, and in amounts which reduce the risk of environmental losses, including emissions of greenhouse gases such as nitrous oxide and methane. 

An important challenge is the development of cropping systems that are sustainable with respect to biodiversity and soil quality, including soil organic carbon stocks. Recirculation of organic residues (manure, crop residues, organic waste, biochar) may stimulate soil biology and fertility, but also poses challenges with respect to environmental losses during handling and after field application.

Selected focus areas are:

  • Emission of methane during manure management for agricultural use
  • Contribution of nitrification and denitrification to nitrous oxide emissions
  • Methods to reduce nitrous oxide emissions and nitrate leaching, e.g. using nitrification inhibitors
  • Effects of organic residues on soil microbial activity
  • Role of microorganisms in maintenance of soil carbon stocks