Increasing Organic Matter and Biology in Pastoral Systems | Sabbatical Fallows

Over the next month we are going to write a series of posts about how to increase organic matter and biology in pastoral systems. This is a very important topic and one that can have huge implications on a farming system. The posts are going to focus on the following topics:

  1. Diverse Pastures
  2. Topping
  3. Sabbatical Fallows
  4. Compost
  5. Targeted Biological Inputs

3. Sabbatical Fallows

 A sabbatical or, pastoral, fallow often involves the ‘spelling’ of a pasture from early spring (August/ September) to autumn (April/May). During the fallow much organic matter (plant litter) is returned directly to the soil surface. This includes nearly all the N fixed each year by legumes. The accumulation of organic N, as plant litter, continues until the pasture is mob stocked in autumn. This ‘pulse’ of organic N returned in the plant litter over the fallow might improve winter and spring production after the fallow.

In the longer term the soil’s improved N status might ensure more effective use of applied fertiliser and the build up of humus improves the soil structure and performance for the next season.