User avatar
ID jit
Green Thumb
Posts: 339
Joined: Tue Nov 01, 2016 10:00 am
Location: SE New England: zone twilight or 5b... hard for me to tell some days.

What's the goal of the actual result of composting?

I read somewhere that the NPK values of compost can range for some extremely low like .5 - .5 - .5 to 4 - 4 - 4 depending on components used, age and a bunch of other variables.

I get
  • the reasons why diversified contents yield better compost and never using more that 10% of one ingredient.
  • the C:N and the balance between high lignin content vs strait high carbon content.
  • the compost retaining moisture in the soil and have a handle on the soil balance thing. Too much of one thing is just as bad as not enough of another necessary component.
  • the microbe colony digesting bulk matter into more plant absorbable nutrient - basically taking whole plant chunks and breaking it back down to its simpler / molecular conponents to feed other plants.
  • the redistribution of trace elements as well as N, P, K, Ca, etc.
What I am trying to wrap my brain around is what is the more beneficial aspect of working compost into the soil? Is it the organic matter itself with the N, P, K, Ca, etc. or is it the transplanting of the microbe colony into the soil which will continue to eat, digest, excrete and eventually die and be eaten, digested and excreted again?

Is it the colony we are re-establish / fortifying in our gardens or is it the rather low NPK, etc values that we do this for?

(Yes, I wish I could think inside the box too.)

Thanks much.

User avatar
applestar
Mod
Posts: 30515
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

I compost because its ridiculous to throw away stuff then buy fertilizer and soil amendments, reduces garbage and paper recyclables from my house to landfill/waste stream, and, as actual result, because I believe in soil microbe and biosphere diversity ...as you put it --
transplanting of the microbe colony into the soil which will continue to eat, digest, excrete and eventually die and be eaten, digested and excreted again?

Is it the colony we are re-establish / fortifying in our gardens

ACW
Senior Member
Posts: 152
Joined: Mon Sep 13, 2010 7:20 am
Location: London

Running 3 compost bins,using kitchen scraps over ripe fruit n veg ,retired pot plants,brought in plantain and sweetpotato peel from work ,freebie newspaper ,the leaves as kindly collected by the street sweeper.
this have over recent years has added 6 inches to my small raised bed ,meant no purchases of any thing bar a small seed starter compost .a little lime !
This also means lots of stuff not going to land fill ,including newspaer ,cardboard ,cotton and wool clothing thats past it ,waste feather and fur from my fly dressing.

User avatar
rainbowgardener
Super Green Thumb
Posts: 25279
Joined: Sun Feb 15, 2009 6:04 pm
Location: TN/GA 7b

You understand it pretty well. As well as removing wastes from the landfill stream, as people have mentioned, adding compost to your soil does all those things you mentioned: it adds nutrients, not only NPK, but a ton of trace and micro nutrients that aren't in standard fertilizers (these include boron (B), copper (Cu), iron (Fe), chloride (Cl), manganese (Mn), molybdenum (Mo) and zinc (Zn) and a bunch of others), it improves the texture of the soil, improving both drainage and moisture holding, and it adds in a whole bunch of beneficial soil micro-organisms (bacteria, fungi, etc) that help the plants be able to use the nutrients. AND it adds in macro-organisms like earthworms and other detritivores which also help break down nutrients into usable forms and improve the soil. All of these are vital; it is not a question of which one we are trying to do. And nothing else you can add does all of these things at once.

And keep in mind, while the concentration of NPK in compost is low, it is used differently. Most synthetic fertilizers, you put a tablespoon or two around a shrub or large plant. If you use much more, you can burn the plant. Compost you apply in shovelsfull. The two shovels of compost you put around that shrub may have as much total NPK as the two tablespoons of fertilizer.

User avatar
applestar
Mod
Posts: 30515
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

Yep. And micro-organisms are what breaks down the available minerals and even nitrogen compounds (is that the right term?) that are ALREADY in the soil into plant-available forms. And the living-dying-decaying recycles the nutrients and minerals, including what the deeper-rooted plants have absorbed and brought up from far below surface soil levels.

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Composting feeds the soil and provides carbon and a few nutrients to feed the soil microbes, fertilizer is still needed in some soils as intensive planting is hard to support without it.

In a forest environment, the soil is actually nutrient poor because most of the nutrients have been taken up by the trees. The trees convert those nutrients to leaves and through photosynthesis recycles the air taking in CO2 and respirating O2 while the sun shines to keep us breathing. Leaves and branches fall, trees make fruit and fruit falls, the animals living in the forest live poop and die eventually returning what they have eaten and stored to the soil. The leaves branches and fruit falls and decomposes in layers. All of this replenishes what has been taken out. Composting is trying to take a short cut to mimic this process.

In a vegetable garden or on a farm, more is taken than replaced, that is why food production was limited and prior to the invention of synthetic fertilizers, it took more land and more people engaged in farming to produce enough food to feed the population. Most ancient civilizations like Chichen Itza and Mesopotamia, Egypt became great and powerful because of their ability and skill in efficiently raising crops that provided food security for a large population. With food security, people were able to spend more time on the arts, engineering and specialization of jobs. Some civilzations vanished because of civil war or invasion, but a few disappeared at their height for no apparent reason. Some of those lost cities showed signs that the city grew larger than the land could support, leading to internal strife. Human pollution, cutting down the forest to make way for more farmland and firewood changed the environent significantly. Some agricultural techniques which initially was of great benefit, later became a liability. Diverting rivers, dried up communities down stream. Irrigation of the land increased crop production but over a couple of hundred years the salt deposited by the man made irrigation channels accumulated so to this day the land around the fertile crescent (mesopotamia is now modern Iran) is so salty that it is difficult to grow any crops there. Remember in ancient times there was no synthetic fertilizer. Egypt was a rich land with good fertility thanks to the annual floods, but with the dams, to control flooding, farmers now have to use fertilizer and their crops grow poorer every year.

History will repeat itself if no one heeds the lessons.

Dams along the Colorado have diverted so much water that the Colorado River no longer reaches the sea and the land that was once lush is now becoming a desert. The more forests that burn or are cut down and the more civilization encroaches, the worse our environment gets.

Farms are fewer and larger but with modern techniques and fertilizer fewer people and mechanization allow fewer people to provide more food on less land. Intense farming cannot be sustained infinitely as was seen in the 1930's dust bowl era when prairies were converted to farmland and when there was drought their was nothing to keep the wind from blowing the soil away.

Intense farming means more contamination, especially around dairies and piggeries where a large number of animals are kept in a relatively small space. The piles of manure run off into streams and waterways polluting them and can carry diseases like e.coli, and salmonella to farms downstream. This would not happen if the manure was spread out instead of piled up. Manures need to be hot composted to kill pathogens or aged 120 days. Over application of fertilizer, not to mention human waste ends up in rivers, lakes, and oceans, fueling algae blooms that remove light and oxygen from the water, killing fish. The Great Lakes are so polluted with human waste and fertilizer runoff that most fertilizer sold there is phosphate free. It is also why Tide doesn't clean as well as it did when it contained phosphates.

When you plant a vegetable garden or a landscape and you either eat the plants, put it in a compost pile, or toss it out with the trash, nutrients and biomass was removed from that part of the land. In nature, plants would fall and decompose and replace what was taken out. When humans remove the bulk of the plants that took the nutrients out of the soil, they have to replace it.

It is hard to replace what was taken out exactly to keep things balanced. Too many nutrients or nutrients in unbalanced proportion have detrimental effects on the soil environment. This is where a soil test is helpful in guiding how much needs to be replaced. Fertilizer replaces nutrients, but microorganisms need nitrogen and other nutrients and carbon to thrive. Synthetic fertilizer would also provide nutrients and the plants and microbes don't really care what the source is. Fertilizer regardless of source all contain salts which is not good for the soil in the long run. However, fertilizer is not a balanced diet, carbon is also needed. That carbon would have come from the plant residues or biomass. That is what compost mostly is composed of, carbon with a few left over nutrients. Most of the nutrients in the plant wastes went to the organisms that decompose the plants and some seeped into the ground under the compost and the rest returned to the air.

Compost would be best if you actually, divided your garden and set aside one of the sections for compost, then rotate the compost pile to a new section every year. Adding compost only adds a few nutrients but it adds needed biomass. The other way to do this would be to plant cover crops that are tilled in to provide biomass. The fertilizer you feed the cover crops will be sequestered in them and some are good scavengers of leftover minerals as well. As the crops are tilled in and decomposed, they will slowly release the nutrients stored in them. In that way, compost would be more akin to the forest environment it is trying to mimic. There is also a no till movement, which can work in some places, where cover crops are cut but not tilled in and they are overseeded instead with the cash crop. Tilling in a forest is done by earthworms and other animals rooting in the forest but large sections are not uncovered. Tilling large areas with machines or even a shovel will expose microbes to the air and sun and a few million of them will be killed in the process.

The organic movement is based on the principal goal of feeding the soil and in turn having the soil feed the plants. That is why organics is not certified in pot culture except for some herbs and seedlings (intended to be transplanted out). Potted plants don't feed the soil or the soil community and require more fertilizer to feed the plants because the soil in the pots cannot sustain the plants. You can grow a plant organically using organic methods in a pot, but it would not be organic by NOP standards to grow a tomato or any crop to maturity in a pot because it is not sustainable.

User avatar
ID jit
Green Thumb
Posts: 339
Joined: Tue Nov 01, 2016 10:00 am
Location: SE New England: zone twilight or 5b... hard for me to tell some days.

Thanks for the replies.

Am going to relegate compost-into-the-garden into the full-on art side of stuff. No nuts and bolts, nothing is easily measurable, nothing really calculable, neither hard, clean, quantitative nor qualitative data to collect because there are far to many variables... Pretty much something which thumbs its nose at analytical pragmatism. Nurtured compost is better than haphazard compost, and even poor compost isn't a complete failure. Shovel it on, till it in and let it do its things.

Creating better compost, that still resides in the science side of stuff, and all the data readily available and research has already been done.
applestar wrote:... including what the deeper-rooted plants have absorbed and brought up from far below surface soil levels.
Have a plan for bocking 14 comfrey on a problem area out back the has no top soil of any type- strait sandy glacial till with next to no clay component. Hoping I will have time to get that done this year, but there are a lot of steps preceding the comfrey. This included making soil for 3' X 25'-30' for tiger lillies which will go in back of the sibreian iris which are already there. Basically I am trying to beat back the weeds on a gravel down slope. Want to put the comfrey behind the tiger lillies.


Imafan26,
Am actually aware of much of what you responded. Was fascinated by the charcoal soil the Inca made and like many, baffled why they piled it soooooo deep I some places.

I freely gather all the stick, twig, scrub and branch fuel load off the woods floor, leaving some but spaced far enough so when the place does eventually go up, the pieces I leave behind wont be able to ignite each other. I won't disturb the leaf liter or any decomposing wood though. The sub soil is very close to the surface. There are places here you cannot walk through because of all of the fallen branches and the like. (Basically try to clear a fire break around the house.)

Thanks for the effort it took to type all of that. It connected a bunch of dots for me.
rainbowgardener wrote:And keep in mind, while the concentration of NPK in compost is low, it is used differently. Most synthetic fertilizers, you put a tablespoon or two around a shrub or large plant. If you use much more, you can burn the plant. Compost you apply in shovelsfull. The two shovels of compost you put around that shrub may have as much total NPK as the two tablespoons of fertilizer.
Thanks for pointing that out. Often I become so involved in how all the pieces fit and work togeather that I forget to look at the picture.

ACW,
I have drunk the compost koolaid and am a believer. I get 3 things out of composting: Free fertilizer; less trash and no piles of yard waste; and time alone because turning a compost pile looks like works and everyone stays away from me if it looks like work is involved.

imafan26
Mod
Posts: 13962
Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

It is not just compost you are making, remember you are building the soil community. The soil is a microcosm of the greater world. If it is done right it is recycling with zero waste. However, pieces cannot be taken out of context. That is why compost should contain a variety of source materials instead of just one. And to remember every action will generate a reaction. If you want to make the reaction positive you do have to consider the bigger picture in regard to the effect on the total envrionment and how any action changes things. Well made compost for the most part creates a positive reaction.

toxcrusadr
Greener Thumb
Posts: 970
Joined: Thu Sep 09, 2010 4:50 pm
Location: MO

>>pieces cannot be taken out of context

Well said. What the OP listed in the first post is all happening at once, and I for one cannot pick out one thing that is superior on that list. Actually, depending on your soil and climate and growing needs, different aspects of the compost will be the most important in any one situation.

Do watch your soil nutrient content - test the soil every few years. If you add compost over a long period, depending on soil, you can start to have a buildup of P and K. Especially in clay.

estorms
Senior Member
Posts: 263
Joined: Thu Dec 15, 2011 7:04 am
Location: Greenfield Township, PA

I have rocky clay soil. Composting really fluffs it up. I used to have trouble digging a hole to plant tomatoes. After four or five years of composting it is becoming noticeably easier to work and weeds are easier to pull out. I have five 4X4X5 foot compost piles. They are under a hickory tree because nothing grows there anyway. Whenever I turn them, I put the finished compost on my raised beds and flower gardens. I have about three acres of yard and all the cut grass and leaves go to the compost piles. If I have too many leaves I just throw them on the garden and till them in.

In the spring, I put newspapers and magazines on the ground to prevent weeds and use grass clippings to cover them up and look nice. I am lucky to live in a rural area where no one complains about compost. I also like the idea of not wasting things. Between burning, composting, and the chickens, I have about one McDonald's cup of garbage a week. Of course, I am in my seventies and don't have baby diapers. (Yet)



Return to “Composting Forum”