I would never use grass clippings - full of weed seed.
I wouldn’t use straw anywhere that I would not want wheat growing 
My mulches are wood chips from tree service companies and mulched leaves from a wealthy guy up the street whose crew delivers scudloads every fall for free.
Bummer is my wood chip source seems to have blacklisted me for some unknown reason.
Live to learn and/or learn to live!
I have lean the lesson or experience so I won’t use it again in the future.
I can get wood chips from the tree company, that’s what I got it for my orchard! That’s a good idea to get leaves as well.
Absolutely! I learned the hard way 
I’ve never burned them with the fresh manure. I’m basically composting over the roots of the plant. when i put down the chic manure , its on top of whats left of last seasons wood chips , then i bury that with another 3in. of fresh arborist chips. i don’t use chic manure every year . only when i see growth slows. but i do put down 3in. of mulch every year. i think its the worms and leaching that move the nutrients to the root zones. i also wait until my plants are actively growing and the soil warms before i mulch. doing it today actually. my arborist dropped off a large load yesterday.
I simply use a 90 day polymer coated urea that I buy in large quantities, bulk from an agricultural supplier. Greenish blue color. The best commercial slow release synthetic home fertilizer, or as good as any is Osmocote.
Grass clippings are high in nitrogen and if they aren’t soppy make most things grow fast, if they are soppy they can suffocate tender young plants. Grass is usually mowed before it can produce seeds.
The Back to Eden principle is not a one season experiment.
The idea is to build the soil over time. It tries to emulate what happens on the forest floor
Mike
Commercial fruit production outside of wine grapes in this country spends little time on the question of brix because the market is mostly about yield per acre and appearance and storability of fruit.
I can’t verify it with research, but it seems irrefutably logical that in humid regions, years of mulching trees, especially with wood, gradually increases the amount of available water in the soil significantly. The result is a gradual reduction of brix during years of ample rain during the ripening process. Big fruit with big watery cells. Also trees with excessive vegetative vigor.
It’s something that anecdote enforces in my own orchard, so now I let sod grow to the trunks of trees once they are adequately bearing trees.
There is one more difference the mulch does - it keeps soil cooler. So if your test was in spring when the soil was still warming up, then the bed with mulch has cooler soil, and that is not a benefit in spring. But it is true for any mulch, not just woodchips.
@GardenGekko, your garden beds look really nice and neat. My own approach is much more haphazard.
Not much to add one way or the other on which mulch to use. The big rough partially broken down chucks from the compost pile are what I use for the most part. If the plants are growing well and throwing some shade, I don’t use any mulch at all as it becomes a pest habitat. I also use a pretty light Nitrogen hand in all of my growing, mostly compost and organic water insoluble fertilizers. I found high N fed plants to be more attractive to pests. All gardening is local, so your mileage may vary.
MES111 - I consider everything i do in the garden to be about improving the soil over multiple years - including applications of compost, mulch or wood chips. I think my takeaway from this trial and some of the comments is that it is wise to compost or age the chips for a year or so. That seems like a better outcome than applying too early and loosing a growing season.
I was pretty surprised as well. It definitely could be something bad in the chips. For context, it was approximately one tractor bucket load spread over a 4x10’ bed.
One of the articles I’ve seen agrees with the vegetative growth comment, noting statistically significant increases in trunk diameter. No citation on that… sorry.
In my situation, I NEED the moisture in the soil. When I put in the posts for my orchard fence, maybe sometime in July, the soil at 3.5-4’ depth was seemingly bone dry.
My soil type is “mineral” with less than 1% organic material. I have a looong way to go before my apples become water balloons.
Yup, the thing about horticultural studies is that there are far too many variables to fully take into account for entirely reliable guidance. Species, varieties, root stocks, soil type, weather …And then there is the researcher’s natural tendency to exaggerate the significance of their research (more funding please).
As long as one takes this kind of info almost the same way as anecdotal evidence, it’s helpful.
Whats good for the orchard is not necessarily good for the garden. Old Hay works wonders in the garden. Years ago i dug out two feet of soil in a 15x 10 area and filled it with wood chips and chicken manure. It took years for the chips to break down. The area is very rich and it now grows things like kale very well. It maintaims high levels of moisture even though the wood chips broke down years ago. I covered the top with loam soil and clay soil. Wood chips are not what i recommend applying year after year for the garden
My experience here is unlikely easily reproducible by everyone. My daughter has a bunny and my compost pile collects large amounts of bedding and bunny poofs (what she calls them). I plant my garden, surround everything with a good layer of still pretty identifiable bedding a poofs and then mulch to a depth of 3-4 inches with wood chips. My tomatoes and peppers are going like gangbusters (almost 3 feet tall with flowers already).
The woodchips for me help with moisture and this encourages the breakdown of the bedding and poofs faster (I find lots of worms each time I peek under the chips and they are fat and happy)
Scott
I got so sick of weeds in my veggie bed that i laid down cardboard and put woodchips on top of it…that usually buys me a growing season.
maybe our high rain amount makes it break down quicker here. literally 3in. of wood chips is nearly gone by the next spring. maybe snow cover has something to do with it as well. been doing this every spring for 6 yrs. now . if i dig down there is 4-5in. of black soil full of worms on top of my red clay. the mycelium in there is incredible. in my raised beds, i just turn in the wood chips that were on top in the fall. i also add some blood/ bonemeal at the same time to prep it for next growing season. in spring i dig down in there and theres no sign of the chips. maybe a piece of a stick here and there that hasn’t fully broke down. just nice black soil that has only gotten better over time. idk but ill keep doing what I’m doing until i see poor results but so far its only getting better and better. every environment isn’t the same but here in the northeast it works well.
if you add more every spring they will stay weed free. I’m lazy. i hate pulling weeds! its a win/ win situation. eventually as my trees get bigger and shade more grass ill stop putting down the chips but under my cane fruit and bush fruit ill always keep them mulched to keep weeds out, hold moisture and feed my plants as it rots. its worth the few hours to do it to save you days of weeding and fertilizing. this year my pile is mostly cedar, so it will keep the bugs away near ground level and last longer under the trees. used occasionally its ok but i wouldn’t use it every year as it can start to stunt growth if the oils build up in the soil.
I wonder if having a bed with a rich healthy fungal ecosystem from years of mulching with wood chips helps to rapidly break down the next annual batch.
Do you remember if your first growing season was that successful?
yes it was and seeing how much mycelium is in there id say thats whats going on. i also inoculated my wood chips with wine cap mushroom mycelium about 5 yrs ago. and I’m still getting some come up here and there all over the yard.