Silvopasture is essentially multi-purposing land for both raising livestock and tree crops. It was and in some areas around here still is a technique used in this hilly locale. It is a method that some of the 80 acre farm's first farmers utilized.
The layout was determined by them, and it is quite logical. The "top" of the hills were cleared and somewhat flattened over time. These were the tilled plots for crops. The steep hill sides and valleys were pasture/orchard/ wildlife.
Tucked into the various wooded sections near the barn are also old overgrown ruins of what once were chicken coops and what looks like an area for pigs (just a guess. Either it was meant for pigs, or someone went a little crazy with the fencing.) Some of these wooded pastures are being swallowed up by nature as the landscape hasn't been grazed in many years. A lot of junk has been hidden in the woods by previous residents. In the U shaped pasture.. at the bottom of the "U" is a massive junkyard. Everything from glass bottles to an old dishwasher, and old furnace, right on to a burned out car. That is a clean up project we will tackle later.
The farm was primarily dairy cattle and black walnut lumber. The pastured areas were mainly cleared of black walnut (toxic to several livestock, but as well to fruit trees) and that is where the apple, pear, plum orchard was planted. Back in the day the fields were alternated of various crops. After a field was harvested or cut, the cattle were rotated to that field for grazing, which then gave the primary pastures time to recover. I don't know the accuracy of this as I do not have any dairy cattle experience, but the farmers around here move cattle out of pastures that have apples. I asked about this and was told that they believe cows will dry up if allowed to feast on fallen apples. Instead they leave it to lure yet another prize.. whitetailed deer and turkey.
This was just an example I wanted to show of old style silvopasturing. The concept can be scaled down significantly and altered to suit different needs. It is combining trees for various uses (lumber, fuel, fruit/nut crops, bee forage, wood working, fencing, etc.) with an understory crop and as well able to be used as a sheltered location for animals, a windbreak, and a means to help energy efficiency of a home.
Which trees to use? Several considerations need to be taken into account when selecting trees. Speed of growth, utilization properties, toxicity (if you are working with livestock), maturity size, compatability with surroundings, canopy spread/ density, invasive potential, soil condition, etc. Shade is also a big thing to take into consideration. Taking note of how much shade is cast and the effect on the surroundings. Some with a thinner canopy may let you get away with berries planted underneath, while others block out so much light that many plants could not produce a crop (unless you consider mushrooms!)
An example of this would be my ponderings of planting a black walnut grove. If I have the proper spacing I can also plant Black Locust. Black Locust grows rather fast, it is a very good rot resistant wood which makes it a good candidate for fence posts or even for constructing raised beds. It has a highly invasive property with the ability to send out many seed pods as well as suckers. However it is not resistant to juglone. So while it would encourage the black walnuts to grow upwards more quickly and more straight by competition, it would not be a long standing companion as the black walnut will essentially kill them off in about 2 decades. Black Locust is an excellent wood for fuel with a high BTU and good burn time. It is a nitrogen fixing tree and also produces a potential bee forage crop. It is toxic to many livestock however, so the placement would not be in a pasture (even though it has wicked thorns that would deter nibbling.)
Right now my Mom is getting some estimates on a few of her black walnuts. Value of the tree is determined by quality and size. To give a ballpark range on the value of these trees.. it can be a few hundred per tree on up to $2,000+. That is when someone else is coming in to cut and carry them away. Nut crop vs wood crop in this case. The methods for achieving the best lumber isn't the most ideal for nut harvest (shorter trees for harvesting and more spacing for heavier yields.)
The black walnut grove is only a concept right now. Reality is that it is a VERY long term crop and one that I quite frankly will doubtfully be alive to benefit. Unless I somehow live well into my 100's..lol. It would produce nuts well before that, but still well over 20 years from planting.
For now I am identifying what species I do have, what qualities they offer, and how they would fit best into overall land management.
I mean.. it was no small coincidence that the old timers situated the pig pen where the oak trees grow. (Acorns a bountiful and well loved crop that fattened up the pigs in the fall.)