Winter Grazing (Browsing)

What you're looking at here is a small stand of bamboo bent down with snow. I snapped this photo back in late November when we got about a foot of just-the-right-weight snow to lodge the canes. The mound is between 2 and 3 feet deep in the middle. In the embedded video you can see what it looked like a month later. About 2/3 of the canes shook off the snowload and stood back up.

This means we've taken another small step toward grazing our cattle in the depths of a snowy winter here in central New York. Last year I wrote an introductory piece about this experiment that can be found HERE. If you're not already well versed in what winter grazing typically looks like in a snowy climate I have another blogpost HERE from Thanksgiving when my cows grazed through a fresh snowfall.

And now to the list of questions and concerns I had/have about the feasibility of grazing (browsing) bamboo deep into winter. I now have tentative answers to some of them.

1. Establishment costs for bamboo groves are very high. Purchasing enough rhizomes to plant an acre of ground could easily cost thousands of dollars (Seed for pasture/hay mixes is an order of magnitude less). There may be some techniques for bamboo propagation that will effectively allow for many starts to be created with less labor than digging rhizomes requires. I have not yet tried it, but apparently there is promise for a lower cost way to make many starts than digging roots entails.

2. Insufficient research on the feed value of standing bamboo is available to make informed decisions. The few forage samples we've sent in for analysis are encouraging on this front. More tests of more varieties under a wider array of climate conditions would be really great. See forage sample results at the bottom of the post.

3. Non-existent information about how best to manage livestock to harvest bamboo. I'm confident that if the other pieces of this bamboo puzzle fall into place that I'll be able to figure this one out by applying managed grazing tools and techniques.

4. Unknown whether a stand of bamboo will tolerate yearly defoliation and still remain the dominant plant in a given area (this is probably location and climate dependent). This is critical and still very much an unknown. To be worthwhile the stand must both yield enough forage every year to pay for itself AND persist over time. I'm guardedly optimistic the stand will last since the shoots die completely every winter in my zone 4 climate so the stand is already effectively losing all its leaves every winter.

5. Unknown how much hoof traffic a bamboo grove will tolerate before culms are damaged and the stand suffers (this is probably type of bamboo, time of year, size of animal, and type of soil dependent). I'm pretty sure any grazier worth his or her salt will be able to account for this and not damage the bamboo.

6. Unknown possible yield of forage/acre (this is location and bamboo species dependent). This is the biggest question we have left. I don't know yet whether the stand will get thick enough to capture the majority of available sunlight from June through killing frost and put on enough growth to be valuable as a stockpile. In the few years of observation of this little stand, the new shoots emerge in patches. Given more time it may send up a more evenly distributed array of shoots. I don't want or need a monoculture of bamboo, but I do want it to be thick enough to be the dominant plant in the areas I devote to it, otherwise the total yield will probably be too low to justify growing it at scale. One management step that I think will help is to graze cattle (and/or sheep) over the bamboo ground in early May. By "overgrazing" the competition early in the spring before the bamboo shoots emerge, the cool season grasses that "naturally" dominate my pastures can be stunted. If bamboo is ready and willing to fill in this could be a good management technique to encourage more bamboo growth. There is also a possibility that the cool season grasses growing under a bamboo canopy would be more palatable than the bamboo leaves. If this is the case then a mid-summer pass of grazers could also be taken and this would go a long way toward making the concept work out on a total forage/acre/year basis. I expect an even more vigorous stand in 2017 than I had in 2016. I intend to take a 10 x 10 ft plot and defoliate it completely and then weigh the leaves for a projected yield number. That will happen in the fall because the canes push new leaves on the ends of their branches throughout the growing season. Most of the leaves come out by late June, but just guessing, between 1/4 and 1/3 more leaves emerge over the remainder of the summer and early fall.

7. Unknown fertility requirements (type, amount, and timing of fertilizer application to optimize quality and yield). I don't have any more knowledge on this front than I did two years ago.

8. Palatibility (will the livestock eat it?). Unequivocal "yes", they will eat it. Ten minutes in and they were munching away on it even with bellies already full of hay. See video.

9. Invasivity (not sure this is a word, but presumably you can figure out what I mean). I am not concerned about this. Yes, I'm planting a "running" types of bamboo, but in my climate they only run about 6 ft per year. I have no doubt I could eliminate the planting entirely by set stocking a few head of beefers on top of the patch as the new shoots come up in the spring. The stand of bamboo would run out of gas under that type of depredation by grazing livestock. I also have pigs. I'm sure I could get them to dig out the patch if I decide I want them to. It does not spread by seed so there is not a risk that it will behave and spread like Japanese Knotweed or Kudzu. And from a bigger picture perspective I am not concerned because I believe in the value of diversity, even imported diversity, and having stand of bamboo on my farm increases the over all diversity and resilience of my enterprise. All of the valuable perennial forages my cattle currently eat are Eurasian - red and white clover, brome grass, orchard grass, timothy, etc - and they all spread by seed, so I don't think I'm straying far from the accepted agricultural practices of my region to try something new. I'm not a complete head-in-the-sand about so called invasives, many insect and fungal transfers are really terrible (Emerald Ash Borer anyone?), and island ecosystems are particularly vulnerable to disruption from imports. But this particular experiment doesn't fall into any of those categories.

10. Other climates? I think bamboo is a potential crop well worth exploring in other climates. I could see it being a really valuable winter stockpile in places that are just a hair warmer than my farm - warmer parts of New England, western NY, much of PA, Ohio, mountainous VA and WV, and out into the humid midwest. Farther south I envision planting groves to use as drought reserves. The volume of leaves bamboos can hold when they grow year after year without winter kill is impressive. Going into a stand with a chainsaw one could bring a lot of leaves into reach for ruminants if other feed became unavailable. Or, even better, plant varieties that don't get really tall and let the cattle figure out how to ride the canes down. There is ample historical evidence that early settlers eradicated large swaths of North America's native bamboo (river cane) from the Carolinas and deep south out through Missouri. I bet most of the eradication occurred from letting cattle and hogs loose on the groves and then rounding them up once slaughter time rolled around. Bamboo really can't tolerate its new canes being eaten off time after time. With tighter management to keep animals at bay during the shooting season, bamboo could potentially be a useful piece of many grass farms' rotation.

11. Help me out? I would love other farmers and researchers to test this idea more. If you know anyone in a position to do a well controlled study send them my way. We'll contribute land, cows, and labor towards evaluating this concept as fully as possible. If other farmers want to start experimenting it doesn't take much to begin a small test planting. Feel free to contact us at info@cairncrestfarm.com. We're happy to email and/or chat over the phone about what we know so far.

-Edmund

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