nitrogen – Aquarius-Systems

Weed Harvester Removes 2,656 Tons of Milfoil From Cazenovia Lake

Tue, 21 Dec 2021 21:48:00 +0000

In the absence of chemical pesticide treatment on Cazenovia Lake in New York this summer, crews used an aquatic weed harvester to control the invasive watermilfoil.

During the four months of weed harvesting on the lake, town crews removed 354 boatloads — 2,656 tons — of invasive milfoil weeds from the lake. The harvesting also removed 11,000 pounds of nitrogen, 17,000 pounds of phosphorous and 5,800 pounds of potassium from the lake.

In 2015, town crews harvested 423 metric tons of weeds from the lake.

If the harvester wasn’t on the lake this year, it probably would have been unusable.

Nutrient Pollution Drives Nitrate Problems in Decatur Drinking Water Source

Fri, 17 Dec 2021 15:59:14 +0000

Surrounded by some of the world’s richest soil and home to two major grain processing plants, Decatur has long been a hub for agribusiness in the United States.

One major trade-off comes in the form of excess nutrients, specifically nitrogen and phosphorus, that runoff from fertilizers used on local farm fields and from discharges from wastewater treatment plants and factories.

In an effort to make the water safe to drink, Decatur, Illinois constructed a $7.6 million nitrate reduction facility in 2002. But, that does not mean the nutrients have gone away as runoff from farms in the lake’s watershed and wastewater discharge from heavy industry find their way into the lake and, eventually, beyond.

What Is Aquatic Weed Harvesting and What Results Should You Expect

Thu, 16 Dec 2021 22:21:51 +0000

What is Harvesting?

Operational Considerations for your lake.

Expected Results from a Weed Harvesting Program.

Most aquatic plant harvesting systems will cut and remove submersed plants to a depth of five or six feet. As this biomass is removed from the lake, the water is immediately ready for use and there are no restrictions on use of the area that might be experienced with herbicide or some biological control treatments.

Removal of this biomass prevents its eventual decay and settling to the bottom, helping to reduce sedimentation in the lake. There is some nutrient removal with harvesting too, as the nitrogen and phosphorous that is bound up in the plant exits the water body. Harvesting is usually not lethal, leaving behind an oxygen and possibly habitat producing plant, which may be desirable in some situations.

Many harvester managers have witnessed a reduction in nuisance plant growth after a few years of repeated harvesting. The plants showed signs of stress and came back thinner, lower growing, and more scattered than before. In some cases desirable plants were able to out compete the nuisance plant growth.

The Pros and Cons of Phragmites

Wed, 01 Sep 2021 14:38:27 +0000

Phragmites, the 12 feet tall perennial grass that aggressively colonizes and forms dense stands in freshwater wetlands can be eradicated using herbicides, but it takes years of repetition. The glyphosate components in the herbicide stay in the ecosystem which can lead to loss of biodiversity, making them more vulnerable to pollution and climate change. An alternative to eradication is burning, but the ash only fertilizes next year’s growth.

Phragmites obliterate nearly all other plant life, it changes a marsh’s hydrology that affects flow and habitat for baitfish and degrade conditions for birds along with altering water levels by trapping sediment.

Researchers know that phragmites doesn’t have many weaknesses, but salt is one of them and conservationists are restoring salinity to Rhode Island waterways by removing dams and restoring tidal flow. While the invasive plant is still there, it is stunted and numbers are reduced enough to allow less-suffocating plants to reestablish.

And after efforts to eradicate or reduce plant numbers, conservationists begrudgingly say phragmites may actually help save the marshes from climate change issues such as rising sea levels. These rising waters force the salt marshes inland, phragmites root networks retain peat in marshes and could help future marshes migrate to higher ground.

The phragmites are also excellent at capturing and storing nutrients. The plant locks elements such as phosphorus and nitrogen in its stalks and roots and also absorb industry legacy pollutants such as cadmium and lead. The biomass is also effective in storing carbon which is a chief driver of climate change.

So, do the benefits offset the harm?