The effects of composts on soil physical properties and crop growth

Climate change has a major impact on agricultural production. By the end of this century, climate models project that Belgium will experience wetter winters and summers with prolonged dry periods. Rainfall events will become more intense. Especially drought-sensitive sandy soil is threatened by this climate change. Those soil types are frequent in the Flanders region of Belgium. This study helps to make soils more resilient against drought by using different types of compost. A pot experiment was conducted in the experimental greenhouses of ILVO-Ghent University to evaluate the application of different types of compost on soil physical properties of both sandy loam and loamy sand soils. Seven compost types have been investigated, including High-quality green compost (BC), vermicompost (VC), green compost (GC), fruit, vegetable and yard compost (FYVC), Spent mushroom compost (SMC), Manure compost (MC) and Bark compost (BC). The composts were applied in different doses, 350 kg N ha-1, 200 kg N ha-1 and, 350 kg N ha-1 + biofertilizer, and three ways of application were tested, incorporated, mulched or as compost tea. A soil without compost amended was used as control. The irrigation schedule adopted for the experiment was based on predicted climate data. In comparison to other application rates, the results showed that the highest application rate (3.5kgN ha-1) of applied composts has the most effective impact on water retention, dry mass, and water productivity in both soil types. Bio-green compost and spent mushroom compost had greater effects on lettuce productivity compared to others. Compost tea had shown no significant effect compared to the control in both soil types. Application of composts to sandy loam showed a greater effect on soil properties compared to loamy sand soils.