There is another tree species that is dominant in my pasture: the native persimmon Diospyros virginiana. Every wild species from opossums to deer to canines to birds flock to these trees when the fruit falls. Currently, the base of all my existing persimmon trees have the snow dug out by deer because most of their other food is under an foot of crusted snow.

J Russel Smith in Tree Crops (1929) (pp 99-100, 303) outlines 5 main points in favor of persimmon trees being grown as tree crops:

1. Little preference to soil structure
2. Little preference to soil fertility
3. Length of Fruiting season (Late August to February)
4. Automatic storage, most fruits are held until after the first frost when animals generally have switched to stored feeds
5. Most nutritious fruit grown in the Eastern US at time of publication (Shown below)

To demonstrate point 3, here are my persimmons photographed on the first of March still bearing fruit.

Persimmons have a few drawbacks as well. Its slow growth and deep root system yields expensive nursery production and difficulty in transplanting. However livestock seem to have a distaste for the persimmon leaves which allow them to grow without protection or interruption of pasture activities. Each livestock animal loves to eat the fruit though!

For now, I will be collecting persimmon seeds for planting into deep containers to provide rootstock for grafting. Once they are grown, I will graft either the best native trees in my pasture, or experiment with grafting other varieties or species of persimmon. To conclude, here is my youngest stand of persimmon. The most prolific bearers will likely be cloned for additional fodder trees.

Since I started researching the practice of silvopasture, the Honey Locust has become one of my favorite plants. Some of the amazing properties: good burning wood fuel, mildly rot-resistant lumber, food for humans and animals, fast growing, nitrogen fixing, erosion control and many more advantageous properties. At least in the plants that existed in 1929, the bean pod fruit of honey locust has a higher sugar content than any other plant, produces more heavily and requires very little labor. J Russel Smith says it best in his 1929 book Tree Crops (warning: large PDF):

CHAPTER IX
THE REAL SUGAR TREE
Several generations of Caucasian Americans have called
the sugar maple the “sugar tree.” It had been done before
by countless generations of American Indians. Rare indeed is
the person who will not say that maple syrup and maple sugar
are delicious.
The sugar maple is a fine tree. Its spring sap has from 3 to 6
per cent. of sugar. It grows over a wide area of cold, rough,
upland country with a poor agricultural surface and in some
cases a poorer agricultural climate. Possibly plant breeding
could do with the maple wonders similar to those it has
already done with the sugar beet—namely raise its sugar
content several fold in a century and a quarter.
But why wait? Behold the honey locust! Look at Figs.
34 and 36! There is a wild tree, native, hardy, prolific, and
yielding beans more than a foot long.
The beans from some of these unimproved and unappreciated
wildlings carry 29 per cent. of sugar. This is equal to
the best sugar beets and more than the yield of the richest
crops of sugar cane. This, too, after man has been struggling
with the sugar cane for centuries.
And Mr. Secretary of Agriculture Jardine tells me that
his department has no time for such new things as honey
locusts, that they are busy with the bugs and bites and blights
of crops already established. Such is the scientific side of this
democracy!
Who will apply science and horse sense to this wonderful
bean tree, which may hold a hundred thousand gullying hills
with its roots while its tops manufacture the world’s sugar
without the arduous toil of women and children on hands and
knees pulling weeds from among the pesky little beets?
Consider the history of the sugar beet, and it seems perfectly
reasonable to picture, fifty years hence, a thousand mountain
farm wagons hauling locust beans down to the sugar factory
in some Carolina valley.
This sugar factory should also sell thousands of tons of cow
feed, rich in protein and having enough molasses left in it to
make the cows fight for it.

 

Many nasty, thorny specimens of Honey Locust grow wild in my pasture already so the many agricultural uses of this tree have gotten me quite excited.

Nitrogen Fixation

First off, Gleditsia triacanthos is a leguminous tree meaning it fixes nitrogen into the soil from the atmosphere. Most legumes complete this process through a symbiotic relationship with bacteria performed through root nodules. But wait, honey locust does not have root nodules and thus cannot fixate nitrogen?

That has been the scientific consensus since the lack of root nodules on these trees was documented. However much evidence is being made apparent that even non-nodulating legumes fix nitrogen via a process that is not yet understood. It is actually a very controversial subject that has been fun to track. This 1996 Honey Locust Newsletter from the University of Virginia department of agroforestry documents the first scientific dispute to the idea that non nodulating legumes cannot fix nitrogen. Summarized, Jim Bryan in his 1995 doctoral dissertation at Yale’s Forestry department found evidence that Honey Locust (among many other non-nodulating legumes) fix nitrogen. His finding were confirmed in this 2006 issue of the same publication,

Direct evidence was also noted that Honey Locusts fix nitrogen in this laughably expensive source.

Honeylocust leaves and seeds contain more nitrogen than they should. Even higher than nodulating legumes at the same site (another paywalled source) which brings me to the next point.

Leaf Drop

Honey locust leaves are high in nitrogen and their small size means they are quickly broken down then incorporated into soils providing an improvement.  Similarly the

Form

of Gleditsia is one that minimizes the shading of pasture and resulting decrease in growth of pasture grasses. The same small leaflets and open form of the tree provide some shade that cools the pasture and lessens water loss from evaporation without blocking all light. The following image shows a tree nearing maturity and the tendency for grasses to grow right up to the trunk.

Fruit Bearing

Honey locust is a regular bearer and rarely fails to crop for a year. In fact, every second year the fruit yield is massively increased. The tree produces from the age of 3 to the age of 100 years old (Source). Average annual production for 9-10 year old ‘Millwood’ and ‘Calhoun’ cultivars was 59kg according to a 1940s Auburn University study (source). Pigs, birds, goats sheep and cattle all relish honeylocust pods but sheep and [maybe] goats are the only animals to fully digest them. The large size of the pods makes them very easy to gather and they reportedly store identically to grains. Livestock that cannot fully digest the pods will disperse the beans via manure.

With some processing, sugar is easily extractable from the pods for use in food, beverages and fermentation. The waste of this processing is molasses rich fodder for livestock.

Miscellaneous

Sprouts from undigested beans in undesirable locations can easily be moved as honey locust is easily transplanted. Root suckers and grafts are both well suited to this tree and clone the genes of the parents tree. So heavy producers can be cloned for the rest of the pasture. Honey Locust leaves and the soft thorns of young plants are also a great food source for grazers. Direct browsing or cut and carry of leaf filled branches utilize unwanted saplings. Additionally the tree grows very fast and produces early (3 years after planting).

The roots and form of the tree also contribute significantly to eliminating soil erosion from precipitation and wind. Similarly, North-South rows of the trees are effective windbreaks in pastures. Honey Locusts are well adapted to even the poorest and rockiest soils.

Bottom Line

Soils classified as rocky outcrop are extremely well suited for the honey locust trees. As the goal of my pasture management is to build soil quantity over the exposed limestone, the roots will help hold soils in place as they are build and the leaf litter will supply nitrogen-rich biomass. Over 100 pounds of fodder loved by my livestock that is dropped by each tree is a bonus that negates any negative effect the shading of the trees has on pasture grasses. Lastly, if the trees don’t work out for whatever reason, I have hard high-quality timber to harvest.

The pasture is full of these trees already and I have personally watched deer devour the bean pods. It is already a perfect fit without any management efforts.

Tree Crops by J. Russel is a fantastic book and available for free as the copyright has expired.

J. Russel was so ahead of his time as the book was published in 1929. His thinking aligns with my goals so much that he has moved into my top 3 list of deceased people with whom I would like to have a drink. Grafting trees is fascinating and I wanted to dedicate a portion of my garden to growing my own root stock. This book is invaluable in providing the guidance I need to determine which trees to propagate for myself and my animals.

Keep in mind that the publication of 1929 predates the Dust Bowl Era in the united states and Russel’s main argument is that tilling land is destroying our soils through erosion. His right to a “told ya so” is possible the greatest depressing one in the history of ecology and agriculture. By extensive travelling all over the world, Russel noted two main points:

1. Tilling land is arguably permissible in flat terrain with absolute perfect and consistent weather scenarios but has been dangerously adapted to sloped terrain or regions with inconsistent precipitation resulting in every precipitation event washing away topsoil leading to deep gullies.
2. Observing throughout the world that areas with staple diets of tree crops have the least erosion and are the most sustainable farming model through all of recorded history.

He goes on to list many viable species that begs for experimentation in hybridization. However he notes figures of production by the genetically unaltered native parent trees, even averaging all qualities of specimens in entire countries. Economies developed around sustainable agroforestry of chestnut trees in Spain and France, Carob trees in Hawaii and the Mediterranean nations, etc. are compared to corn economies in different US regions. Spoiler alert: the tree-based economies win by a landslide. He argues that research in to breeding hybrids with more variety like every other crop in human history would only increase the viability, profitability and value of tree crops. Also noted is the need to develop mechanized post-harvest processing equipment to add even more economic potential to tree crops.

Tree Crops can be summarized as a collection of observations and anecdotal evidence as well as private orchard data Russel compiled after being continuously rejected in his pleas for experimentation, research and funding from the US Department of Agriculture and other agricultural entities. He seems to have a bone to pick with Secretary of Agriculture Jardine as he continuously responded to J Russel’s request for science by saying they need to devote all of their resources to existing crop diseases. The science presented in the book is solid such as noting that American farming practices are destroying soil 8 times fast than any other civilization in history or that Chestnuts in the mountains France and Spain outperform corn in the matching climate mountains of Appalachia.

I’m only a quarter through the book and wish I had more to learn from this author. I can’t imagine the anguish he went through when his unanswered pleas led to the dust bowl era or when the American Chestnuts of his childhood went all but extinct.

I plan to order 2 hardcopies, one to mark up then keep in my library forever and one to loan out.