They really need to update that paper with some better information. That is what you get when you chronically underfund the extension services and all the best and brightest bail to private industry to make more money. I had to pull up the source material the article because my bullsit meter went off.
After reviewing the source material, you are 100% completely wrong :-)
First off the “transfer” of N from alfalfa to a grass was stated in the sourcing paper to be from mineralization of roots. Aka decomposing plant parts.
Perennial species often grow new roots and abandon older roots every year.
Alfalfa will abandon and regrow new roots after every cutting as the plant pulls carbohydrates from the roots to grow new stems and leaves.
The thing is that the grasses will do the exact same thing. Older roots die back and newer roots grow. So it’s more of mutual swapping of N rather than a one-sided legume being leaky.
In the old world, agriculture started in the Mediterranean and temperate regions. The domesticated species are mostly winter annuals or adapted to a Mediterranean climate (dry summers, wet winters).
New world species are mostly subtropical or tropical species. Corn, potatoes, pumpkins, beans, tomatoes, peppers, etc are all warm weather crops. This is a major reason the large population centers developed in the tropical and subtropical areas.
Populations in the North America domesticated other species like lambsquarters and erect knotweed. However these species were not as productive and they gave them up when corn and beans were traded for from present day Mexico.
So the least experienced farmers with the species, were the first ones the Europeans ran into in North America. :-)
The Europeans reported the three sisters methodwith some tribes in the northeast. The accounts are all very jumbled and contradictory. The tribes in New England also appear to have have been relatively new to growing. All three species were not found together in New England before the 1300’s. If they did grow them this way they could only do it one season in a location. They would have to change locations then next year.
Fundementally you can’t plant corn/pumpkins repeatedly without a break. It’s a mega attractant to the rootworm beetles which are endemic to North America. If they did not rotate they would have crop failures after only one season. Beans also have all sorts fungal and bacterial diseases. The only way they could control them is via rotation/fallowing.
What was done in mesoamerica for thousands of years was rotation. They were the ones that domesticated the three species and built large civilizations from the extra food availability. They grew bush and vine beans, corn, and pumpkins. They also grew casava, tomatoes, peppers and other species. When yields started to decline, they would fallow the ground and move their plots.
There is evidence that the Mayans for over 500 years mostly figured out how to avoid fallowing their fields. They would grow 3 cycles per year in rotation for a large surplus of food.
The whole three sisters thing was an early crop rotation method. Not all together like as advertised.
Beans where grown first as they are shallow rooted and produce about 50% of the nitrogen they need. If they harvest 25% of the crop and till under the rest they have around around a 25% increase in a available N.
The next season is corn and pumpkins together. They are both heavy N feeders. They spaced out the corn a lot more than modern hybrids so the pumpkins had plenty of room to grow and shade out weeds. They unfortunately share the pest of cucumber beetle species (corn rootworm).
The next season they had to go back to beans to break the rootworm cycle.
Eventually other nutrients would become low (P,K, micros etc). Other pests and diseases would buildup. They would rotate onto new plots letting the old plots go fallow for a while.
My wife teaches Bilingual middle schoolers (spanish/english). Around 40% of the kid’s Moms are from Mexico.
To get the kids to clean up the classroom she has a small list of school appropriate “Cleaning songs”. She never announces it or tells them to clean up. She just turns the music on 5 minutes before class ends.
All the kids with Mexican moms, pop up and start frantically cleaning. The other kids, after a bit of confusion, follow.
She says “I might as well take advantage of all the Pavlovian training their mothers have done.”
I personally hate them for most of the same reasons that you like them.
First off they are slow to use. Part of that is because things are buried in menus, and part is from the annoying up-selling screens. Using them take 4-5 times longer in my experience. I don’t go there often enough to justify it.
Second, if you are paying cash, you still have to wait in line and see an actual human. Might as well just order with them.
Third, I am nearsighted but I have good glasses. The small font on the menu boards don’t bother me. I would rather see the entire thing while in line. Make my decision and order to a person.
Lol. A swing and a miss. Not even close to what I said. Try again. Since your from, Texas perhaps your should see a Dr about concussive brain trauma.
Here’s a hint. Divide 40million by 2 cows per acre and you get 20 million. That’s about how many acres we need to use to feed every cow in the U.S under irrigated annual crops production. Instead we use around 800 million acres (grassland plus forest).
So 97.5% of the land are we are using to graze cows, we don’t need to use. We do it because the government subsidizes archaic agricultural practices and makes it affordable.
A 1,200 lb lactating beef animal needs around 3% of it’s body mass every day. So around 35lbs of dry matter forage per day. Works out to around 6.4 tons DM/year.
Under irrigation, In areas without freezing temps, 25tons DM/acre is possible (not easy) or 4 cows. In areas with freezing temps 12-15 tons DM/acre can be accomplished or 2 cows (1 cow if the growing season is short)
10-15" rainfall zone produces around 600lbs DM/acre of which around 50% is available (timing issue) this is around 0.15 tons DM/acre. 6.4 tons DM for one cow is around 43 acres.
In a 5-10" rainfall zone it reduces to under 200lbs DM/acre total. Or 0.05 tons DM/acre or around 128 acres per cow. With that much walking their energy needs increase by as much as 50%. Or around 200 acres/cow.
Guess who grew up on a ranch with BLM grazing ground :-) My grandfather decided going bankrupt was a better than listening to a younger more hotheaded me.