How Growers Can Address New Challenges in Plant Nutrition
Greenhouse and nursery producers operate under constant pressure to deliver uniform, high-quality plants on predictable production schedules. Whether producing bedding plants, ornamentals, or vegetable transplants, growers depend on reliable inputs, especially growing media and nitrogen fertilizers, to maintain crop performance. However, in recent years, both of these foundational inputs have come under increasing scrutiny due to environmental concerns, rising costs, and supply chain vulnerability.
Nitrogen remains the primary driver of plant productivity across horticultural systems. Adequate nitrogen supports vegetative growth, canopy development, and overall plant quality. Yet the global nitrogen fertilizer system is both energy-intensive and vulnerable to disruption. Most synthetic nitrogen fertilizers are produced through the Haber–Bosch process, which converts atmospheric nitrogen into ammonia under high temperatures and pressure. This technology transformed agriculture in the 20th century, but it also requires substantial energy inputs. Today, ammonia production accounts for approximately 11% of total energy use in the global chemical industry and roughly 1% to 2% of total worldwide energy demand.
Global production of ammonia is also geographically concentrated. China produces approximately 26% of the world’s ammonia supply, and Russia more than 10%, while the U.S. still imports about 12% of its ammonia. Recent disruptions, including the COVID-19 pandemic, geopolitical conflicts, and natural disasters, have highlighted the vulnerability of agricultural systems that rely heavily on centralized fertilizer production and global supply chains.
Even when fertilizer is available, a substantial portion is not captured by plants. Studies estimate that up to 50% of applied nitrogen fertilizer can be lost to the environment through leaching, volatilization, or runoff. In greenhouse and container-based production systems, these losses can be amplified because substrates have limited nutrient buffering capacity and irrigation is applied frequently. As a result, nitrogen may move rapidly through the root zone before plants can fully utilize it.
These inefficiencies represent both an economic and environmental challenge. Fertilizer losses increase production costs while contributing to nutrient-rich leachate that is receiving increasing regulatory attention in many regions.
At the same time, the growing media used throughout the horticulture industry is also facing increasing scrutiny. For decades, peat has been the primary component of greenhouse substrates because of its desirable properties. Peat provides high water-holding capacity, good aeration, low bulk density, and favorable chemical stability, characteristics that support consistent plant growth across a wide range of crops.
Globally, an estimated 30 million cubic meters of peat are harvested each year, and approximately half of that volume is used in horticultural growing media. However, peatlands are also important ecological systems that function as long-term carbon reservoirs and unique habitats for biodiversity. Because peat accumulates extremely slowly, often over thousands of years, its extraction is increasingly viewed as the use of a nonrenewable resource. These concerns have prompted researchers, regulators, and industry groups to explore strategies that maintain substrate performance while reducing environmental impacts.
Together, these two challenges, nitrogen efficiency and substrate sustainability, are encouraging the horticulture industry to explore new approaches to nutrient management.
One emerging opportunity comes from an unexpected source: the rapidly expanding insect production industry. Insects such as mealworms are increasingly mass-reared for use in animal feed and alternative protein production because they efficiently convert low-value organic materials into high-protein biomass. As this industry grows, it also generates significant quantities of by-products.
Two of the most abundant by-products are frass, the manure produced by insects, and exuviae, the molted exoskeletons shed during insect growth. In commercial mealworm production systems, frass can accumulate in quantities up to 40 times the biomass of the insects themselves. This material typically contains 3–5% nitrogen and approximately 70% organic matter, suggesting strong potential as a nutrient source in horticultural substrates.
Exuviae represent another underutilized resource. These shed exoskeletons contain chitin, the second most abundant natural polymer on Earth after cellulose. Chitin and its derivatives have been associated with enhanced microbial activity in soils, gradual nutrient release, and stimulation of plant growth. In several systems, chitin-based materials have been linked to increased plant biomass, improved nutrient uptake, and enhanced plant resilience through interactions with beneficial microorganisms in the root zone.
Despite this potential, insect-derived materials remain largely unexplored in greenhouse substrates used for floriculture and nursery production.
For additional information on new advances and theories on dealing with plant nutrition management challenges, including a look at the role of plasma-activated water (PAW) in floriculture production, please read the original article written by Pamela Andrade and found on the American Floral Endowment (AFE) website.
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