2013 conference paper
Strategies for developing sustainable substrates in nursery crop production
International symposium on growing media, composting and substrate analysis, 1013, 43–56.
A comprehensive literature search of industrial and agricultural by-products to replace or extend existing soilless substrate components would produce a seemingly endless list of materials from “garbage” to a plethora of manure-based composts that have been tested both in the laboratory and in crop response studies throughout the world. Many of these alternatives have shown promise, but limiting factors for integration and use of the alternatives substrate components continue to include: regional or national availability; transport costs; handling costs; lack of a uniform and consistent product; guidelines for preparation and use of materials or impact on current crop production practices. If a product can overcome the above limitations, then researchers are tasked with documenting substrate physical or chemical characteristics. The objective in all studies is to maintain or increase growth of nursery crops and to extend the longevity and acceptable physical properties for long-term woody ornamental crops. Proof of results is determined using laboratory analyses and crop growth studies. Physiochemical properties are monitored over days, weeks, and months to ensure stability. Particle size distribution and varying ratios of substrate components are manipulated to achieve optimal air filled porosity and available water content. Soilless substrates are amended with lime, sulfur and nutrients or blended with other substrate components to provide optimal chemical characteristics. Additionally, substrates are evaluated under industry conditions to determine impact on water, nutrient and pest management to better understand obstacles to commercial adoption.