When you say 'digging' what exactly do you mean? Have you created a trench, and have been filling that? Or have you just been digging holes, tossing in table scraps and covering them back up?

It's not really the lack of nitrogen which presents the problem, you can always supplement. The problem is more of how you are 'digging'. If, for example, you did trench composting, you would start at one end of the trench and, depending on your soil's bio-activity, it would be ready to plant the next year.

If you planted into unfinished compost, the problem is more along the lines of how roots and soil interact. First, decomposing organic matter is undergoing chemical reactions, and thus, not consistent enough for plants to extract what they need. Another problem is heat. While we call some plants 'heat loving', few plants (probably no veggies) can tolerate the type of heat emitted by a large mass of decomposing matter at the root level.

If, however, you've just scattered the scraps around, it shouldn't be a huge problem. I do sheet composting. Instead of burying the scraps, or making a pile, I use a thick layer of mulch. When I have a plate of scraps, I lift the mulch and toss them under. When it's raining and the mulch is sloppy wet, I don't even lift... I just toss them on top. I find that most scraps are indistinguishable from the mulch/decomposed Organic matter in about a month. Generally speaking, I treat my garden beds as if they were giant worm bins. And yes, the soil (not to mention the incredible amount of worms) seems to be benefiting.

the heat for normal amount of kitchen scraps is negligible. IME, they can contribute to fertilization fast, because they are eaten by earthworms and become castings fast. I don't know that you should ever stop, organic matter at depth helps, and high N OM helps too. IME, one trash can of kitchen scraps mixed with leaves completely fertilizes one 4X12 bed.

Heat, when trench composting, is of so little concern as to be non existent. Whether kitchen scraps would contribute much "fertilization" fast depends on many factors beginning with what was in the at the beginning. If there was little to no organic material in the soil at the outset there will be little activity by the Soil Food Web to convert those scraps into nutrients the plants can use and that includes earthworms.

In years past I have done trench composting, in soils already well endowed with organic matter, and found that I could continue to bury those scraps right up to planting time with no noticeable problems with plant nutrition. But in soils with little to no organic material plants did show nutrient deficiencies, whether from the soil bacteria utilizing all available N or because the nutrients simply were not available
I cannot say.

The question now becomes what is going on in that soil? Are the scraps you have been digging in being digested or are they just sitting there?

kimmq is kimmsr

Thanks to everyone. About my digging, I dig a hole 24"x18" about 12" deep and fill it with the scraps and grounds until it comes to within 6" of the top. I then dig another hole (nearly touching the end of the first) with the same dimensions and use this soil to cover the scraps in the original hole. I continue the until I get the bed the length I want and then reverse direction, always making sure the holes nearly touch each other. I continue until I get the bed the size I want. Not exactly trench composting, I guess.

kimmq: So with the possibility that some of the soil is deficient in organic matter, it might be well to stop the digging in the scraps well before planting time ... like immediately! Right?

rgreen48: Can I assume you do your sheet composting during fall, winter and spring only and not during the "growing" months?

Gary, no, I sheet compost all year. I keep a thick layer of mulch around nearly all my plants. The exceptions are when I broadcast a block of greens or something similar. However, as I increase the number of my planting beds, I'm leaning away from the broadcast method. I just keep a pie plate of scraps, and when the pie plate is full, I bring them out to the garden, lift the mulch, and toss them under. Easy as that. Now, I never have that load of nice fluffy, fresh compost everyone loves, but my method works for me. I don't get the positive effects of the heat, and the heat-thriving micro-organisms, but I do get the fungi, many of the microbes, and the worms... so many worms! And no turning lol. I also get no loss of nutrients through run-off.

So, when compared to traditional 'pile composting', year-round sheet-composting is slightly different, but it brings all the benefits of organic matter to my clay soil and works for me. My philosophy when starting the method was to mimic nature. How does nature create humus? By layering organic matter on top of the ground and allowing the soil web to eat, poop, reproduce, and die lol. Pile composting does have it's advantages, and I would never put it down. Trench composting is also a good method, and very efficient for quickly improving a 'poor soil'.

In your case, since you have a 6" layer of soil on top of your 'trenches' Your fine to plant. You may though, find that the ground will 'sink' a bit as the scraps continue to be broken down.

rgreen, what do you mean by "broadcast a block of greens"

thanks

Keep in mind that when raw organic material is put into soil the Soil Food Web may choose to go to work on it and temporarily tie up available nutrients as they do. Putting kitchen scraps on the soil, under the mulch material, is not the same as putting those kitchen scraps into the soil.

I would leave several weeks lead time from when I dug kitchen scraps into the soil to when I would plant, if the soil was pretty devoid of any organic matter.

kimmq is kimmsr

Broadcasting a 'block of greens' refers to sowing a designated area by just spreading the seed thickly in a 'block'. The traditional way of sowing is down a row with spacing and thinning. Then bed and square ft. gardening became popular. This usually relied on transplanting, or direct seeding plants into the beds with designated spaces. However, another, very old method of sowing greens (such as mustard, kale, turnip, etc... - even spinach and radish) was to till up a square (like a 10' x 10') in the garden and just toss the seeds like you were sowing grass, or wild flower seed. Then you take a garden rake and lightly 'scratch them in'. There are lots of variations on the theme. Some people will do long 2' - 3' wide rows and spread the seeds thickly. In any case, broadcasting results in a very thick stand of plants that you can either cut with a knife at the base, or a hand sickle to harvest a lot at once, or to walk through the block and just pick the leaves you want for dinner. Here where I live, it's very common to see the 'old timers' with a stand of greens that they eat off of all winter long. Most of the types used will live through our winters, or at least to Dec., die back, and come again in spring.

I do my own variation. Since I prefer 4' wide beds, I will just spread the seeds in 'blocks'. Last year I did a 2' x 2' block each of kale, and turnip greens. I just sprinkled the seeds over the space with no care about spacing. As they grow, when they get big enough for steaming, I will first look for where 2 seeds sprouted in the same space, and cut off the weaker one with scissors. Then, the rest of the season I would cut-and-come-again, taking just the larger outside leaves. That progresses quite a while, then, as the plants bolt from the heat, time to harvest the tops like you would broccoli raab. A 2' block of greens provides quite a bit, especially if you have a small space.

Edited to mention: Those 'Old Timers' I mentioned usually mixed the different seeds together before broadcasting them into the garden. That way, each handful sliced off was a salad, or a mixed greens side dish. One favorite dish here is what is called 'wilted greens', or wilted lettuce. It's delicious, and when there is a little each of the mustard greens, turnip greens, kale, spinach, lettuce, whatever... it's absolutely delectable!

Btw... some seed sellers sell mixed greens for broadcasting. The mesclun mixes are an example, and are usually harvested earlier than other mixes.

Oh, and I forgot to add... in this area, both the stand in the garden, and the harvested product, are referred to as 'a mess'. As in: I planted a mess of greens today. Or, we picked and ate a mess of greens for dinner (and dinner = lunch lol, never supper. Supper is Supper, and always Supper.)

Thanks for all the comments. Just finished doing what I should have done to start with: checking to see what was happening. Took a shovel to one of the first trenches (probably dug last October). The mound has settled flush with the surrounding area. Was I amazed!! Super "soft" soil about 12" deep before encountering any resistance. Other than the beautiful stuff and worms, there were some small pockets of what looked like gray ash ... no sign of anything that had been buried.

Dug into a second site I dug in in January. Unlike the first area, this one gets very little sunlight and stays wetter. The mounded soil hasn't completely returned to the same level of surrounding soil. Digging was nearly as easy as the first hole, was wetter, but the only thing left from the scraps was coffee filters.

The final hole was one I dug a month ago. The mounded dirt doesn't appear to have come down at all. So I shoveled the mound away and dug down 8" from the surface. Lots and lots of worms. The soil, which was very hard and difficult to dig originally. was very "soft" (don't know any other way to describe it). Other than some coffee filters, there were some tiny shreds of lettuce, cabbage and what looked like cantaloupe rind.

I am thrilled. Oops... daughter and granddaughter just moseyed by. Will get back soon.

Again, thank you.

Great! That gray ashy looking stuff is not ash but some type of microbe munching away. I can't remember which at the moment. It's sometimes seen in compost piles too.

You're on your way to great soil!

'I dig a hole 24"x18" about 12" deep and fill it with the scraps and
grounds until it comes to within 6" of the top. I then dig another hole
(nearly touching the end of the first) with the same dimensions and use
this soil to cover the scraps in the original hole. I continue the until
I get the bed the length I want and then reverse direction, always
making sure the holes nearly touch each other. I continue until I get
the bed the size I want.'

I love the sound of that. I can imagine an enormous herd of tiger worms moving from one heap to the next, and all that nutrition is right in the soil (rather than in a giant compost bin where my tiger worms live) and doesn't require you to then put it there. I think a lot of my composted veggie scraps are almost wasted, I move it all so seldom.

I really should be using your method.

Yes, by burying your scraps you have achieved major improvements in major parameters: nitrogen, water infiltration, root penetration, and OM content at depth. Those who compost and spread the compost on top achieve none of the four, although not breaking the soil has some advantages too.

Thanks for your gracious and helpful comments and suggestions.

Can I assume that this practice of burying kitchen scraps should be continued after each growing season is over? Or do you reach a point beyond which the health of the soil won't improve. Silly question, I guess, but I'd like to know. I'll always have kitchen scraps and coffee grounds and it seems like the digging would be much easier next time.

Also, should this impact the pH value to a significant degree? It's been four years since I last had it tested: it ranged between 6.2 and 6.9, depending on which part of the garden was being sampled.

rgreen48: I plan to try your sheet composting in the perennial beds. I was hesitant about digging scraps in between the flowers for fear of damaging their roots. Your method sounds ideal for this purpose.

glib: I think I understand your concern about digging and its effect on the soil. Hopefully the time will come when the soil will be healthy enough and will only need a thick layer of compost around it. (No digging!)

Thanks again!

I doubt the pH will change much...if anything it will go toward neutral, which is what composting does. But probably your 6-7 pH is the natural range for your soil anyway, and it's just perfect for gardening.