The Role of Peat-Free Organic Substrates in the Sustainable Management of Soilless Cultivations

Vegetable and ornamental crops require high input demand to adequately support their standard commercial quality and yield. For these crops, a very high level of agronomic use efficiency of many productive factors can be achieved in soilless culture. For example, the benefits derived from the adoption of soilless closed loops for the recirculation of the nutrient solution are well known as a benchmark of excellence for nutrient and water use efficiency. The challenges that we now face are as follows: (i) making soilless systems more inclusive of sustainable and eco-friendly growing substrates, possibly available at a local level; (ii) replacing chemicals with more sustainable products (e.g., organic active compounds) as much as possible for plant nutrition and protection. These goals can be addressed by following different approaches, but the adoption of peat-free organic substrates may play a central role. This work investigates four organic materials, i.e., biochar, coir, green compost, and wood fibers, to assess their role in plant nutrition and protection when used as components for the preparation of growing media in the soilless cultivation of containerized crops. In further detail, the work highlights how these materials may support normal agronomic practices.