Meeting the Changing Needs of the Specialty Crops Industry with Soilless Substrates

Jeb S. Fields

The specialty crops industry — which includes ornamentals, fruits, nuts and vegetables — is transitioning from field production to more container production and use of soilless substrates (growing media) to allow for more control. Soilless substrates, which are often byproducts from other industries, such as pine bark from the timber industry, consist of relatively large particles to provide ample drainage. Although soilless substrates have been used for years in ornamental plant production, they are new to other specialty crops, which have different needs.

The LSU AgCenter is leading an international team of seven universities and federal institutions that is assessing the current and future state of soilless substrates. Specialty crop growers and allied suppliers across crop types and production systems participated in a three-phase assessment. The first phase involved a survey of more than 300 growers and suppliers to identify immediate needs and knowledge gaps when using or supplying soilless substrates. In the second phase, focus groups of growers from different geographical regions provided a deeper understanding of research wants and foreseeable opportunities when producing small-fruit, ornamentals, tree-fruit, nuts and vegetables using soilless substrates. In the third phase one-on-one interviews were conducted with 12 representatives of regional, national and global suppliers, processors and harvesters of soilless substrates, which include pine bark, peat moss, coco coir, perlite and wood fiber. These sessions allowed researchers to gauge the substrate-related needs of growers and suppliers separately, without influencing or biasing any feedback through expectations.

Many traditional in-ground growers have or are considering shifting to soilless production, at least on some of their acreage. Soilless culture allows more control over cultural practices. This increased precision in production can allow for earlier or increased yield or output per area or per natural resource (land, water, fertilizer, etc.). However, with this transition arises new complications. Soilless substrates currently in use are designed to “finish” crops uniformly and in a relatively short timeframe. Many transitioning specialty crops that yield fruits, nuts or vegetables can require much more time in production to be viable. Moreover, the goal of fruit crops is yield, while the goal of ornamentals is to finish. These two processes can potentially be supported differently by different substrate properties.

Growers and suppliers alike indicated that they need more in-depth and targeted information. They want support in soilless substrate research, especially in regard to decision-making tools, water and fertilizer management, and more regionally specific solutions. New or transitioning soilless growers were interested in return on investment and logistics of shifting to soilless production, while current and advanced soilless growers wanted more information on engineering and designing substrates with specific properties. It was widely desired that online tools or informational guides be developed for the different regions and individual specialty crops.

The industry identified education aimed at growers and suppliers as a primary need, with university research and extension being relied upon for support. New and alternative materials were also discussed in the supplier interviews, as well as continued support of trade organizations, regional associations and research conferences.

Soilless substrate science is necessary for the continued growth and development of the specialty crop industry. Soilless substrates can allow for increased sustainability and environmental stewardship while providing new opportunities for continued expansion and profitability.

Acknowledgement: The U.S. Department of Agriculture National Institute of Food and Agriculture’s Specialty Crop Research Initiative (Award 2020-02629).

Jeb S. Fields is an assistant professor and extension specialist at the Hammond Research Station, Hammond, Louisiana.

(This article appears in the summer 2021 issue of Louisiana Agriculture.)

Alt text: five piles of soilless substrates

These are piles of soilless substrates separated by particle size for research purposes at the LSU AgCenter Hammond Research Station. Photo by Jeb S. Fields

9/3/2021 7:49:05 PM
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