To compost or not to compost

If someone would give you a large amount of organic matter…maybe wet hay or the pulp that comes from processing coffee or anything that resembles green manure. The easiest thing to do would be to take that organic matter and lay it on the ground around our plantain trees allowing it to decompose as a green manure mulch would. It would eventually decompose and become compost.

The alternative would be to create large compost piles allowing it to go through the composting process for maybe 3 to 6 months and then take the compost and spread it around our plantain trees.

It seems to me both processes would deliver the same or similar benefit to the soil but the first process would be much simpler and less work…and maybe even better because there would be no leaching of nutrients out of the compost pile.

What are your thoughts?


I’d say it depends on what kind of material it is, whether you are in dry or rainy season, and how your land looks like soil-wise.

  • Does the material might have harmful bacteria or fungi? → better compost it first
  • Does your land need protection from sun and wind? → better mulch
  • Do you need to build soil fertility? Mulch your area with a part of the material, compost the other part of it and then make compost tea and spread it to your mulched areas.

Rather short, and maybe not thoroughly scientifically based thoughts… :wink:

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You make a good point Martin that it depends on the material. For example if it was sawdust, better compost it first. Yours is also a good point that it can be split into two…mulch and compost.

yes totally agree with what Martin says. Stimulating the exisiting soil organsms to create what they need from the mulched organic matter and living soil, or increasing the amount of soil organisms in a depleted soil - different outputs of different approaches. Biofertilizers can also add the micro-organisms (MO) without needing to compost. More natural way is to mulch but then directly adding green/unrotted material to soil can also lead to problems especially if soil is lacking organic matter (OM) - it can lead to nitrogen defecit (robbery) so good to have a thin layer of OM (like compost) between soil & mulch if green. Or maybe bioferts can do this…

In my opinion, it should be viewed as an economic decision or a decision on how to maximally bless others stemming from your profit invested or time freed up for the Great Commission (discipling others). We need to move away from idealism that leads to other priorities that do not first serve the Great Commission. As income per hour or return on investment (particularly if you have to hire someone to do it) decisions there are so many parameters or circumstances that might affect your decision. Opportunity cost is a good thing to think about. Making compost in a way that it is stacked up high and then turned on a regular basis is a very time costly. That may pay off vs. other competing activities for income that you could do with your time, for example if you are trying to produce vegetable seedlings in trays that need sterile soil. Vegetable seedlings are high value and would justify the cost of turning compost.
If you have very wet material it may make sense to invest a little bit of time mixing in some other drier material such as dried grass, dried leaves, stover, twigs, sawdust, etc, so that it is not so wet so it can compost on its own without additional turning which is time investment. That is assuming you have a use for the compost that justifies the extra time doing that vs. other options for the product. Composting with material that is too wet and too much green material (not the right ratio of green and dry or carbon to nitrogen) will become anerobic and somewhat gelatinous and smell if they are too thick and take longer to turn to compost.
Let’s talk about other options that might result in higher income per hour or return on investment than the normal composting process of stacking and regular turning.
With wet hay you have options for feeding animals and you can google instructions for making haylage or silage. You have to make sure that you are getting the material in a form that can properly ferment without mold and toxins in the product and that it does not already carry those toxins in too high a percent. That will likely be a higher return on investment than compost or mulch. You may even be able to make a business delivering the product to others or reselling it farm gate.
Some people do black soldier fly production, some biogas but you have to consider the cost of setting up to do that and what your alternative income sources for that time and that source product might be. Most of the time these will not successfully meet that test unless you have little land and no saved money and no one who will cooperate with you that allows you access to more land.
Yes it would be fine to put the material around plantains as long as you don’t put it too thick and cause too much heat and cut off air to the roots or you mix other materials to improve your carbon nitrogen ratio. However, you are going to get more benefit by working them into a higher value production system such as with vegetables. I would likely advise you to put some in the planting hole composted or non-composted or partially composted. I have done it all those ways and I don’t really care that much which form I use in the tropics since the soil is warm it composts itself. I add a small amount of human urine whenever it rains (multiple application of a small amount) or when I am going to irrigate to compensate for organic matter that is too high in carbon and I get excellent production without turning compost. If it is wet don’t add too much or it will heat. Or you can add it a month in advance into planting stations and then you don’t have that problem. You put the wet material below the seed or transplant and not on top of it similar to placing fertilizer with some regular soil between and the more you put the more you need to put it off to the sides of the hole in smaller clumps so that it does not heat up too much and it is not too big a clump in one place.
One great use of wet material is to plant a little early or a little late and it serves as an aid for moisture reserve and also improves moisture retention so you may be successful in production with less irrigation or no irrigation at all in rainfed systems. I have coined the term WAD (Water Absorbed Dependency) because I am adding a wad of wet material or unfinished compost. Or when irrigation is cumbersome (i.e. hand watering, particularly if the source is not nearby) or not possible using organic material (particularly wet material) can help bridge the moisture gap between rains since you are starting off with a moisture reserve and organic matter holds 5 to 10 times more moisture than regular soil and also it keeps feeding the plant nitrogen and other nutrients in minidrought situations so that when it rains again your crops still had enough nutrients. Nitrogen must be in much higher concentrations right near the plant when going through a time without rain or your crop stunts and does not recover since nitrogen moves with the bulk flow of water and so it much be in high concentration near the plant when water is limited.
It is not just vegetables that benefit from the above method. Fruit trees, agroforestry trees including living fences can all be established this way. Then also add mulch to the surface for a double whammy. Citrus would only appreciate the mulch in the dry season so pull it away in the rainy season unless your soil is excessively drained. Avocado does not like excessive moisture either so be careful with heavy soil that is poorly drained and then adding wet mulch on top of that exacerbates the situation.
For mulching high value crops are the targets for return on investment of time. Tomatoes are my first target for mulch because it cuts down tremendously on blight (particularly when the material has no dirt in it), particularly if you are in the rainy season and you use wide spacing. Mulching when there is no irrigation and no chemical or mechanical system for removing weeds is premium and a very high return on investment and you are building your soil at the same time.
When it comes to organic matter there are many times you need to focus on volume rather than quality. I don’t put much stock in all the special “brews” people come up with but they may know something I don’t. I just know that large amounts of organic matter make farming in marginal situations much more profitable when they are applied as mulch and in the planting hole. Human urine and legumes (intercropped—particularly perennial herbaceous or tree legumes, relay cropped or cover cropped or rotationally cropped) and animal manure when it is nearby and commercial fertilizer/animal manure you have to buy when you can afford it all are great.
Please be critical or engage with my suggestions as I want to learn from others and see what they think. Iron sharpens iron.

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Dan, I like your focus on economy…time, money, results, etc. That is certainly an important factor to consider in the multi-faceted matrix of decision making. For my particular project, I’ve decided that composting these materials takes too much time and energy that could be better spent on other things.

Traditional Composting requires, at any scale, requires an enormous amount of labor. If you sheet compost you allow the worms do most of the work.


I lean towards Martin’s hybrid approach. The ease of laying raw material around keeps things simple for time and energy. I do this a lot for weed control and moisture conservation. But there are times when a well balanced compost is needed. This allows targeted application, especially for planting stations and more sensitive crops.

The first is easier and no leaching of nutrients but the second may produce more symbiotic nitrogen fixing bacteria that adds nitrogen for growth of the plant

I can very well follow Dan Janzen’s comments, and would like to underline them and briefly complement them:

  1. The classic compost pile is simply too labor intensive and also, in my opinion, not realistic for larger areas. However, if the capacity and curiosity is given for it, it can be very useful to prepare a small amount of compost quite carefully, as a starting point for “compost teas”; from my point of view, this is to be compared to an application of effective microorganisms, where the microorganisms propagated thereby are adapted to the farm, if the components originate from the farm and are chosen as diverse as possible (remains of different plant species, manure of preferably different animals, remains from processing, etc.).

  2. On larger fields, in my experience, “surface composting” (a more ore less thin/thick layer of organic matter distributed on the whole surface => “mulching”) proves to be a more effective approach than the classic compost pile. The layers of organic material hardly become so thick and dense that air is missing and mold forms; rather, the good conditions for plant growth and composting of the material run analogously. Humid and warm conditions favor both; dry conditions cause both to run more slowly. Thus, the risk of leaching of nutrients released during land composting is lower than in a traditional compost pile. In addition, it seems to me that the high heating in the compost pile is an indicator that a lot of energy is used in the composting process. This may deactivate some weed seeds, but it “costs” many microorganisms that are central to soil fertility.

  • An image or kind of imagination: We see the importance of the (fresh) organic material for the soil comparable to the feed for ruminants. The organic material decomposes, becoming “the food of the microorganisms” which are of central importance for the soil fertility, its air and water balance. (In ruminants, the microorganisms multiply in the rumen and a good part of them is digested in the further stomachs as the actual food of the animal.) This picture also helps to find a good measure of how much organic material is sensibly applied: do not overdo it, but rather keep applying a moderate layer frequently, “so that the soil can digest the material well”.

  • The multiplication of microorganisms, (which I consider more important in composting than the input of nutrients) takes place over the entire surface, especially at the transition layer at the mineral soil surface and the organic overlay. At the same time, the microorganisms are protected by the top layer of the organic overlay, which is usually drying out, not exposed to direct sunlight, and also in relative humidity.

  • As an important aspect of area composting, we try to let the organic material used to mulch grow on the area itself as much as possible through green manure plants that are sown at each gap that occurs in the stand and also through rows of shrubby species that produce a lot of organic mass and are cut back regularly. The advantage (besides the fact that then it is not necessary to spend too much time and energy on transport and distribution) is that growing roots also deliver exudates, which in turn promote the microorganisms of the soil.

For these reasons, we clearly prefer “surface composting” to the classic compost pile and try to promote it, if possible, by producing organic material on the field itself (and not just by importing organic material onto it from outside).

I think your decision is smart. There are other ways of using material that often make more economic sense and are more bang for the buck since no one has unlimited time. I don’t find too many people with your perspective. How did you arrive at that decision? I wonder if I can learn from you how you arrived at that decision I could be better at convincing others that composting in many if not most cases does not result in as good a result as mulching or intercropping a legume tree or perennial legume (or even an annual if your dry season is long and severe) if you end up with inadequate mulch. Your decision is very interesting.

Well we are in complete agreement then. Mulching is much more efficient use of time and it is a form of composting and you get weed control from it. I also bring large amounts of organic matter as I can find it and collect it (from being a mulching material “scout”) to use in the planting hole and on the surface. I use human urine to oversupply nutrients (high level of nutrients per plant) so I don’t need to worry about adding brown material to the hole and having nitrogen depletion by microbes using it up. I am a firm believer you need quantity over quality when it comes to organic matter. The microbes need a meal and a bigger meal is an advantage and in the long run results in more microbes. Introducing microbes from tea may work when the material is exceptionally dried out but if there has been enough soil moisture or if you have buried some of the material you are going to have a lot of microbes at least in the underground portion where there is more soil moisture. I don’t make those teas but I think I would make manure tea as a grazing repellent if I was not risking the safety of a crop to be harvested and eaten raw or could be mixed with other vegetables to be eaten raw. If you are a good OM scout you are likely to gain more from time invested in collecting more nearby bulky OM than in time spent on making teas which are not going to have nearly as much impact.

Also a good point on plant exudates. That is why I always turn people on to intercropping when OM is going to be short in reaching or achieving maximal fertility.

I have alot of green weeds on my farm and wish to decompose them.

We treat the green weeds the same way nature treats them. That is, organic matter falls off of trees onto the ground and decomposers naturally in a forest. We try to imitate the activity of the forest. Whenever there is a surplus of weeds or any plants, we cut them and let them fall to the ground to decompose. We call it chop and drop.

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Agreed with many of the other comments - depends on the context and needs, and resources and time available. If using as mulch, just keep an eye out for nitrogen deficiencies, as large amounts of dry material can rob growing plants of nitrogen in certain contexts.

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Beth, do you think there is much chance that dry material sitting on the top of the soil would affect the availability of nitrogen within the soil in the root zone?

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It can do, depending on a number of factors, such as moisture availability, species planted, other stresses, density of plants, season and climate, depth of root systems, and the health of the soil in terms of microbial life. Mulch is usually a good thing overall, though, so I’d say go for it, and top dress with manure or N fert if severe yellowing in old leaves is observed down the track.

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