Mulching is a collection of NbS that focuses on covering the soil and adding nutrients and organic matter to it. This can be leaves, grass compost, twigs, chopped plant material, or even living mulch in form of intercropping plants that grow under the main crop (see crop rotation). The residues help to create a soil structure with plenty of smaller and larger pores through which rainwater can easily infiltrate into the soil, thus reducing surface runoff. As the mulch material decomposes, it increases the content of organic matter in the soil. Soil organic matter helps create good soil with stable crumb structure. Thus, the soil particles will not be easily carried away by water. Therefore, mulching plays a crucial role in preventing soil erosion.  

Mulch applied to a crop is not dependent on any ecosystem and can be applied wherever you grow crops. The effect and outcomes may vary depending on soil type and local climate. 

Why

How

Organic mulching is achieved by applying chopped or whole plants, or even shredded paper, to the soil under or between the crops. There should be a rather thick layer that completely covers the soil and shuts out light.  

The mulch, often as organic material, covers the soil around the crop and protects against evaporation, which increases soil moisture, and represses weed growth. Different organisms will start to decompose the material, and the organic matter and available nutrients will increase over time. Organic mulch usually increases soil diversity and activity, which can also improve soil structure. Furthermore, it can reduce erosion by increasing soil stability. However, some mulches can be more effective than others. Some studies show that yields can also increase. 

The selection of mulching material is important with respect to crop type, management practices, and climatic conditions. There can sometimes be hard to find the amount of mulch needed to cover larger areas of crops. Care must be taken to not spread diseases to the grown crop. Therefore, it is advised not to use mulch based on material from the same crop as grown where the mulch is applied. 

How much do we know

Mulching has been and is used in agriculture worldwide, but to a lesser extent in more intensive agriculture.

Costs

The cost involved includes time for applying mulch and potentially time and new machinery to prepare and apply the mulch.