Interesting, very interesting. I like it. When starting a new soil bed I do something similar; a method called double dig. Dig down the depth of the spade and set the soil aside. Fill the hole with 3 inches of amendments, compost, straw and green matter (fresh leaves, alfalfa, whatever as long as it is green). I have access to mushroom farms and a truck load of spent media is dirt cheap (pun intended). This stuff is loaded with mycelium - bonus. Then raisin stems if I can get them - sugar (old apples). Problem with that is most raisin processors have contracts for cattle feed lots. So I beg and grovel and sometimes it works. Distillers grains are a real plus when available. Go to a local brewery and find out if there is a home brew club around. Home brewers are generally glad to just give it to you. I never thought about adding branches? I do add hardwood ashes. Turn all of that under to the depth of the spade mixing in with the native soil. Now put the top soil back in the hole add 3 inches of all of the above plus any minerals or PH adjustments to this layer. Turn it all in mixing well. Cover with straw or whatever and come back in a year to plant. If you live in the frigin desert like I do you need to water it and keep moist. If you live where it rains a lot cover it with plastic when needed to keep it from getting soggy. From this point on amendments to the soil are worked in to the top 3 to 4 inches of depth.