I would like to clarify some things.
Correct me if I am wrong but, the actual meat from hanging weight is about 60%, so 680kg of hanging weight is equal to about 400kg of meat without bones.
So your highest meat harvest from 1 ha is 80% of what I wrote above.
Also according to USDA data, while boiled lentils with salt
have 1140kcal/kg the raw lentils
have 3530kcal/kg, and the harvested lentils are raw, after boiling the mass increases more than 3 times.
Lentils calories: 3530 kcal/kg * 1200 kg/ha
(thats a more realistic lentils harvest) = 4236000 kcal/ha
My comparison of meat with lentils was because raw lentils
are rich in protein, about 25% of the mass, which is more than in some raw meat.
If I would like to compare calories, 40 000 kg/ha
of potatoes 770 kcal/kg
would be a much more favorable comparison for vegetarians.
But it would not be accurate because meat is considered the main source of protein and we need something vegan providing the same value.
Regarding accuracy I have recently reread the data from my research, and I have to admit that the amount of lentils I wrote in the previous post is too high in comparison to real harvests, I wrote the median amount of legumes in general instead of lentils which is not quite correct.
But for example if we use soy instead of lentils
the harvest is about 2500 kg/ha
and Raw mature seeds of soybeans
have 36% of protein and 4160 kcal/kg
Soya calories: 4160 kcal/kg * 2500kg/ha = 10400000 kcal/ha
I understand your argument about grazing grass but unfortunately the reality in our business oriented world is that on industrial scale a large percent of food for cattle and pigs consist of imported grains and soy.
So to conclude:
Comparing your 1,905,000 kcal/ha with 10,400,000 kcal/ha in the case of soy we get about 5.46 times less calories per hectare in meat production.
And if we consider that only 60% of the hanging weight is actually edible by humans 1,905,000 kcal/ha * 0.6 = 1,143,000 kcal/ha the difference with 10,400,000 kcal/ha from soy is 9 times.
If we compare the potatoes calories which are equal 40 000 kg/ha * 770 kcal/kg = 30,800,000 kcal/ha we get a difference of 26.9 times.
Please correct me if I have made mistakes in my calculus.