Soilless substrate stratification: a review of the past and looking forward

J.S. Fields, J.S. Owen
Containerized crop production is an intensely managed system comprise of highly porous substrates that rely upon natural resources (i.e., peat, bark, water, and mineral nutrients) to quickly provide salable crops throughout the year. The costs of these finite resources have been rising partly in response to soilless production practices expanding into new agricultural sectors and supply chain matters. To alleviate rising costs and supply limitations, researchers must identify new and innovative crop-production strategies. Substrate stratification is an emerging substrate management technique that involves layering unique substrates within a container for more precise control of container-substrate air or water gradient. Results have demonstrated improved resource efficiency, allowing strategic fertilizer placement to reduce overall fertilizer requirements and improved productivity when produced under deficit water management. More recent evidence has shown improved root productivity for crops grown in stratified substrates. Most recently, peat reduction through utilization of stratified systems, peat atop bark, has been successfully employed. Thus, stratified substrates are gaining interest in both nursery and greenhouse production. As we continue to uncover the benefits of alternative media management strategies like stratified substrates, more refined research is necessary to quantify the advantages to growers, researchers, and the global public. This paper will explore the present and future of stratified substrate research, focusing on the beginning theories through current discoveries. We will discuss existing technologies and upcoming experimentation plans to advance stratified substrate science and further explore associated benefits with the goal of expanding innovative agriculture research to yield more cost-effective and environmentally friendly production strategies that are achievable through soilless substrate science.
Fields, J.S. and Owen, J.S. (2024). Soilless substrate stratification: a review of the past and looking forward. Acta Hortic. 1389, 61-66
DOI: 10.17660/ActaHortic.2024.1389.7
stratified, bark, growing media, resource efficiency, peat, layering, rooting, sustainability

Acta Horticulturae