While not yet widespread, organic land management is gaining traction around the country as more is learned about the downsides of synthetic fertilizers, herbicides and pesticides. While not without challenges, organic practices are cropping up around the country and there’s a lot to be learned from the people and parks at the forefront of this movement.
Integrated Pest Management vs. Organic Land Management
So, what is an organic park? These parks are managed under one of two approaches: integrated pest management (IPM) or organic land management (OLM). Both aim to steward the land in a low-impact way that is more in line with natural ecosystem processes, and reduce the use of synthetic fertilizers and pesticides, though to varying degrees.
The focus of IPM is just that: pests. The less strict of the two organic approaches, it allows for use of traditional chemical treatments when necessary. IPM is essentially an approach to scaling back on synthetics and relies on routine inspection, monitoring and reporting to identify a threshold for pest populations. If that threshold is crossed, synthetic pesticides may be applied to limit the amount of damage. The same goes for weeds. To prevent unwanted plants from spreading, land managers develop thresholds that are specific to the site based on an understanding of native species and tailored to streamline labor and herbicide applications.
In contrast, OLM programs do not use any synthetic fertilizers, pesticides or herbicides. Along with the close monitoring and knowledge of the local ecosystem required in IPM, OLM approaches may also utilize organic fertilizers and means of removing pests and weeds. Organic fertilizers are nutrient-rich, natural substances derived from animal and vegetable matter, such as manure, peat or chicken litter, which are rich with nitrogen, phosphorus and potassium. These are slower-acting than conventional fertilizers since they take longer for the plants to break down, but practitioners of organic horticulture have developed some methods to improve this response time, such as compost tea. In this process, natural fertilizers are mixed with microbes to help break them down, and then steeped in water, just like tea. The tea is ultimately applied in spot treatments or by spraying the liquid on the desired area. Compost tea has helped the Rose Kennedy Greenway in Boston — a system of parks managed entirely through OLM — reduce its fertilizer applications by 50 percent, according to Horticulture Foreman Anthony Ruggiero.
The most common method of organic weed management is “mechanical” — removal by hand. While tedious and time-consuming, this is the most effective way to remove unwanted plants and control growth. Other methods include spot spraying with steam or boiling vinegar, and using grazing animals, such as goats, on a large weed infestation. Both steam and vinegar have their downfalls: vinegar produces inconsistent results that vary by weed species, while steam machines can cost more than $20,000, which makes them a far less desirable method of weed management. And, although it’s fun to imagine a herd of goats roaming around cities devouring weeds, this often isn’t feasible for many reasons. For now, it mostly comes down to good old people power.
The Downside of Synthetic Fertilizers
At the heart of all organic management approaches is the concept of “right plant, right place.” Ruggiero advises: “If a plant is not successful in its current environment, don’t waste time and resources trying to make it work. Organics is about getting the right species with proper soil management for that given environment to ensure plant or turf success.” Choosing species that will thrive where planted is the key to an organic approach that works.
While quick-acting and effective, there are many cons to conventional approaches that use synthetic materials. Synthetic fertilizers are made from petroleum or salt byproducts. The compounds used in these fertilizers are water soluble and break down easily in soil, so they quickly provide nutrients to plants, often within 48 hours. Much like carbo-loading or a sugar rush, this gives plants a quick jolt of nutrients, which result in rapid growth. These growth periods often don’t last long though, sometimes not even a full month. The short bursts of growth mean plants are often not able to establish a proper root system, which is crucial for retaining water and nutrients, as well as for strengthening the plant against disease, pests, and wear and tear by park visitors. In addition, extended use of synthetic fertilizers over time depletes the soil of nutrients, making it dependent on frequent applications of chemicals.
Synthetics can do even more damage beyond impacting the stability of a system. Pesticides and herbicides pose serious health threats to anyone who is exposed to the chemicals. In high-traffic spaces, like city parks, this is a cause for concern. Two major ingredients found in common pesticides are glyphosate and 2, 4-dichlorophenoxyacetic acid (known as 2, 4-D). While the use of these substances is allowed in the United States and the U.S. Environmental Protection Agency classifies glyphosate as not likely to be carcinogenic, the International Agency for Research on Cancer has labeled both glyphosate and 2, 4-D as possible carcinogens. There are currently more than 400 lawsuits filed against the Monsanto Company by cancer survivors and the families of cancer victims. These lawsuits blame the Monsanto herbicide Roundup, in which the active ingredient is glyphosate, for causing non-Hodgkin’s Lymphoma.
Beyond human health effects, pesticides are detrimental to many other species, including important pollinators. Some types of neonicitoids, a common insecticide, have been banned in Europe because of their disastrous effect on honeybee populations. Water contamination is also a concern: runoff and leaching from both pesticides and fertilizers can cause algal blooms, presenting further hazards to a broader range of ecosystems.
Organic Management Challenges
These are some scary implications that come with the use of conventional fertilizers and pesticides, especially when applied to beloved and heavily used places like city parks. Luckily, integrated pest management and organic land management offer a way around this by helping scale back the use of these substances or by offering an alternative to using them at all.
However, organic management is not without challenges, with public attitude, perhaps, being the biggest hurdle. While many people are aware of the threats posed by synthetic fertilizers and pesticides, a lack of significant regulations at a federal level means there is often no impetus for change. As people and communities learn more about IPM or OLM methods and see peers attempting to go organic, general support and acceptance is likely to build.
Cost is often the No. 1 concern when it comes to city park management, but, fortunately, it isn’t a major issue for organic approaches. While IPM and OLM can cost the same as a conventional program at the outset and, occasionally, slightly more because of more rigorous maintenance needs, organics often offer a budget break down the line, as the park system becomes independent of the repeated application of synthetics.
There are currently less than 40 communities nationwide that have developed or implemented a complete OLM program for their green spaces, though IPM programs are more common. As practice shifts away from conventional approaches, advocacy groups and university extensions will likely be at the forefront of this effort, and municipalities will also play a major role in influencing change as they continue to seek initiatives and programs that align with organic goals. Finally, land managers and community members need to be further educated on best practices, as well as the costs and benefits of organic land management.
Currently, sharing of information between practicing communities is limited. Most organic networks are regional and, where they do exist, are often geared toward management in rural areas, especially farming and gardening. Heavily used parks, especially those in cities, are a particularly important piece of this equation, and park managers are uniquely poised to be leaders in this change.
See detailed references here:
- EPA Releases Draft Risk Assessments for Glyphosate
- IARC Monographs on the Identification of Carcinogenic Hazards to Humans
- B. A. Woodcock et. al., “Country-Specific Effects of Neonicotinoid Pesticides on Honey Bees and Wild Bees,” Science 30 Jun 2017, Vol. 356, Issue 6345, pp. 1393-1395
Alexandra Hiple is Program Manager for the Center for City Park Excellence at The Trust for Public Land. Derek Bolivar is a former Research Intern with the Center for City Park Excellence at The Trust for Public Land.