Organic matter

It is widely accepted that plenty of organic matter in the soil is the best guarantee for good quality soil. But is it true, and how much is plenty? We take a look at the benefits of organic matter, but also at what isn’t yet known.
Anyone who hasn’t heard of organic matter before is bound to be impressed by this miracle cure. So many benefits in one substance (see box)! But the question is how important organic matter actually is, say Hein ten Berge and Wijnand Sukkel, researchers at Wageningen University & Research. They don’t know whether it is the organic matter itself that delivers the benefits or whether other factors also play a role in the benefits to be gained by increasing organic matter content in the soil. This knowledge is important in choosing the right strategy. For example, how much organic matter do you need in the soil to be able to exploit all its benefits, and do the benefits outweigh the investment needed? What exactly goes wrong if there is too little organic matter in the soil? And then there is the issue of whether it is the content itself that is important or whether it is rather a regular supply of fresh material that provides the soil system with nutrition and energy.