Final Report for FNE12-768
The Water Hyacinth Project explored the value of the water hyacinth as a livestock nutrition source by analyzing the quantity grown and its nutritional value. To determine nutritional value, we took a sample of each harvest to the lab for a nutritional breakdown. In terms of dry mass – the hyacinth, on average, had more minerals and metals, but less fiber and protein than the fresh grass and grass hay that we used as a comparison. It did have a very high water content (90.8%) – which would need to be addressed when determining the quantity required to meet nutritional requirements. To determine quantity grown, we harvested hyacinth at 1 month intervals leaving only a small amount to replenish the pond. Starting with enough hyacinth to fill our floats we were able to consistently harvest about 75 bushels per month in a roughly 125′ x 25′ drainage ditch that was secured with a weir. Overall, we were happy with the results and will continue to grow the water hyacinth in the future. We would also like to see just how fast the water hyacinth can grow – if the timing and harvest quantities are optimized.
Ward's Farming operation consists of 55 acres of owned farm land and agreements for farming roughly 120 acres of hay fields in the area. The focus of this project was on the 55 acre home farm where small quantities of livestock including sheep, goats, or cattle depending on market fluctuations are raised. The farm is well suited for this project as there are large ponds and ditches present on the property. The farm was a bit drier than average during the project period so the water level was lower than anticipated. This may have affected the water hyacinth's ability to grow as large and spread as widely as might have been possible otherwise.
Larry Ward was the owner and farmer in charge of the project. He had one person to help with harvesting and setting things up. Berran Rogers of UMES also assisted where applicable. Richard Nottingham was the technical advisor. He is an Ag Agent at the University of Maryland Extension located at the University of Maryland Eastern Shore (UMES).
The Water Hyacinth Project explored the value of the water hyacinth as a livestock nutrition source by analyzing the quantity grown and its nutritional value. The plant was introduced and analyzed in an area that experiences an overabundance of nitrogen due to fertilizer runoff. The Northeast's climate makes it suitable for water hyacinth growth as the plant's invasive characteristics cannot take hold. Results were distributed at the 2012 UMES Small Farm Conference.
Initially, A weir was constructed in the ditch to prevent the hyacinth from escaping and a float system was made to control the initial planting. This can be seen and is explained in detail in one of the youtube videos (link at waterhyacinth.blogspot.com)
Our starter plants were purchased from an ebay seller (John's Pond Plants) under the name "floating water plants". We purchased ~600 small plants for $600 to start. This filled up the float sections as shown in the video. There appears to be many sellers with different sizes, quantities, and prices for sale.
To determine nutritional value, we took a sample of each (equally spaced by 1 month) harvest to the lab for a nutritional breakdown. These tests were used to determine nutritional values at various points in the growing season. The hyacinth was found to be useful as a nutrition source, so it was used for food.
To determine quantity grown we harvested hyacinth at 1 month intervals. At each harvest all water hyacinth not contained by the float system were extracted. The quantity harvested at each interval was recorded.
Samples of the ditch water itself was also be taken from the growing area for analysis. These samples were taken to serve as reference for other farmers who wish to replicate this project in the future. This analysis will accompany the nutritional and quantity data so that the next farmer can compare their results to ours more directly. If a farmer’s water supply test results are similar to ours, then we expect for them to have similar results through the duration of the test assuming similar climate conditions apply. If they do not, we are unsure what variations would occur.
Our results include the quantity of hyacinth grown, the nutritional value at each harvest, and a water sample.
The first harvest had a yield of 55 bushels. After that the results were consistent across the subsequent 4 harvests at about 75 bushels each. There is a graph attached showing the harvest number and quantity of bushels harvested. To recap - starting with enough hyacinth to fill our floats (which can be seen at the waterhyacinth.blogspot.com site) we were able to harvest about 75 bushels per month after the first harvest. This was all done in a roughly 125' x 25' ditch with a weir to control outflow.
The nutrition analysis was also mostly consistent across time in the moisture, protein, fiber and minerals categories, but the metals varied widely and with no apparent pattern. In terms of dry mass - the hyacinth, on average, had more minerals and metals, but less fiber and protein than the fresh grass and grass hay that we compared it to. This should be factored in when using the hyacinth as a supplement to existing food sources.
An interesting point to consider when examining the results is that the hyacinth is about 90% water per the analysis. This is very important to note - as many other feeds are much lower. This means that even though the hyacinth compares very well in terms of dry matter in a few of the categories with our compared items - the hyacinth will still have less total nutrient value when compared to an equivalent mass. For example - 1.3% of the water hyacinth's dry mass is calcium and fresh grass has 0.55% calcium. We would still need to factor in the fact that fresh grass has less water (51.9% vs. 90.8%) to compare the items. 100 grams of water hyacinth would have 9.2 grams of dry matter - resulting in .12g of calcium. An equivalent 100 grams of fresh grass would have 48.1 grams of dry matter - resulting in .26g of calcium. You would need a little over 2 times as much total mass of hyacinth to replace the calcium that the grass was supplying. This is very important when converting from your standard feed to water hyacinth.
The raw nutrition results are included and there is a spreadsheet attached that compares the hyacinth results with fresh grass and grass hay. It also a includes the roots of the hyacinth by themselves and parrot feather. (we tested these because they also happened to be in the pond)
There are also two water samples included. These can be used to compare a new location with our experiment. Similar water would likely yield similar results and it is unknown what effects differnet results would mean. Our samples were taken from two different parts of the pond and they varied somewhat. Please see the attached raw results to compare.
The water hyacinth resulted in a usable food source for livestock whose supply quickly replenished. This is useful as it can supplement food that would otherwise have to be purchased. Its speedy growth is important because it can be harvested and used several times within a single growing season as opposed to a plant that would need to grow longer for a single harvest.
On the negative side, the high water content means that a large amount of weight will have to be harvested and handled in order to equal the nutrition content of many other feed sources.
Education & Outreach Activities and Participation Summary
A table was set up at the 2012 UMES Small Farm Conference with sample specimens and the youtube videos playing on repeat. A brochure was distributed at the table and it is also available at the blogspot page. Links to all results have been posted to waterhyacinthproject.blogspot.com
We will continue to use the practice as it it seems to be useful and cost efficient. It is is also, in our opinion, visually attractive and in our case seemed to increase the amount of other ditch life that we enjoy seeing and interacting with.
In the future, we would probably not harvest at strict intervals and just harvest as is needed/wanted. You also may be able to optimize yield by harvesting at different intervals or removing a different percentage of the total pond cover. We just went with the size of our little rope floats for simplicity.
It will also be very important to only use isolated ponds or tightly controlled waterways. The speed of growth makes it very easy to see how the hyacinth can be viewed as invasive.
The project did indeed determine how much could be grown and the nutritional value of the harvests given our initial conditions. Going forward, it would be interesting to try and optimize the growth of the water hyacinth for maximum yield. The growth rate is impressive, but the high water content reduces the value of the of the speed of growth. It would be important to grow this as fast as possible to get the maximum value from the plant. We harvested at simple intervals and returned to the same initial quantity each time. There is probably an optimal time span and quantity to leave that we have not found due to the constraints of our experiement.