One of the main purposes of the De Plantuh Man is to share our personal experiences growing food. Everyone has their own tips and tricks, but for a beginner, it may be difficult to know where to start. In this post we’ll describe how we go about collecting manures, mulches and amendments in Barbados. Collecting these resources involves interacting with many persons and I reflect on this aspect as well.
Manures
Manures are one of the most important tools of the organic or backyard farmer. Manures provide nutrients for plants, increase the diversity of soil microbes and improve the physical characteristics of the soil. So far, we’ve used cow, sheep, goat, chicken and even bat manures (also known as guano). Each of these manures has different properties, that is, nutrient content and physical characteristics. These considerations are important, but for the average backyard farmer, who is not necessarily looking to optimize their plant growth, these technical details are not as critical. That being said, I’ll briefly describe important considerations related to each type.
NOTE *: Hotness refers to the amount of nitrogen and ammonia present in the manure. Hot manures contain large amounts of these nutrients, which in high quantities can cause leaves to turn brown and appear burned. Hot manures should therefore not be used fresh and should be allowed to age or composted down for a period of time before application. So far, none of our plants have been burned due to our manure usage. Our chicken manure was aged outdoors for a long period of time and contained a large amount of woodchip bedding which essentially ‘diluted’ the manure. Additionally, manure burn can be prevented by using the manures as a mulch (link to section below) at the surface of the soil, rather than mixed into the soil itself. By doing this, nutrients are allowed to slowly leach into the soil rather than touch the roots directly.
Most farmers are more than willing to give you as much manure as you can take for free. In our case, we just went with feedbags and shovels and just asked the farmers if they’d be willing to give us a few bags which we just filled ourselves. The hardest manure to get so far was bat manure, which we got from Cole’s cave, which was an adventure in itself. In the grand scheme of things, obtaining bat manure may not be worth the effort required to get it, but the experience itself was worth getting covered in mud and sand flies.
Important Considerations
There’s no getting away from it, manures are animal waste and as such can contain harmful pathogens. Because of this, manures should be handled with gloves and hands washed thoroughly after. Additionally, when growing crops that come into contact with the soil (root crops and leafy greens), allow a period of 120 days between application of manure and harvesting of the crop. For vegetables that produce fruits that do not touch the soil surface, allow 90 days between application and harvesting. Manures can be applied to fruit trees without issue as long as the tree is tall enough for the fruit not to come into contact with the manure, either directly or by splashing.
All crops which are fertilized with manures should be washed thoroughly before consuming.
Finally, goat, sheep, horse and cow manures may contain weed seeds that may germinate when applied to the soil. This can be mitigated by thickly mulching after applying the manure or by hot composting the manure before use.
Mulches
A mulch is any material that is applied to the surface of the soil. Mulches are beneficial in several ways:
- Reduces water loss from the surface of the soil.
- Organic mulches decompose and add nutrients back to the soil.
- Mulches suppress weed growth.
- Mulches keep the soil cool.
- Prevent splashing of soil onto plants during watering or heavy rainfall, thereby reducing the chances of soil borne pathogens affecting the plant.
The main mulch that we use is dried grass clippings. We just simply collect cut grass, either from our own lot or from neighbors who are more than happy for us to take it off of their hands. Once dried, which usually takes a couple days in our hot weather, we just apply a thick layer onto our garden beds.
Another mulch that we’ve experimented with is casuarina needle/leaf mulch. So far we’ve determined that this mulch is excellent at retaining moisture and suppressing weed growth. One consideration, however, is that due to the waxy nature of these needles, moisture tends to run off the surface and doesn’t actually reach the soil. One way to mitigate this is to not mulch too thickly and to water the plants directly at the roots by moving the mulch, watering then replacing the mulch.
A more exotic mulch that we’ve used is sargassum seaweed. Seaweed is an excellent source of trace nutrients such as and, of recent, is available in abundance. We simply collect as much as we can, wash to get rid of excess salt then allow to dry directly on the surface of the soil. Overtime this seaweed breaks down released these nutrients into the soil
Tip: All of these mulches can also be used to prevent weeds from growing in a raised bed by applying a thick layer to the bottom of the bed prior to filling with soil.
Amendments
An amendment is any material that is added to the soil that improves the quality of the soil. Be it physical/chemical properties (e.g. pH, water retention or nutrient content) or biological properties (e.g. microbial life). We’ve experimented with several freely obtained amendments so far.
Fish Scraps
Fish scraps are basically the parts of the fish that aren’t consumed and include the guts, head, gills and head. These are an excellent source of nitrogen/ammonia and other nutrients, both macro and trace. The vendors at Oistin’s Market were more than happy to fill our buckets with these.
Now fish scraps smell bad, and flies are instantly attracted to them. What I did was dug a hole about two feet deep where I was planning to set up a raised bed. I then added a bit of diluted molasses to the fish gut mix, covered with dirt then topped it off with a thick mulch. Care must be taken to minimize scent escaping because dogs or cats will dig it up if they can smell it. Also, decomposing fish will generate a lot of nitrogen which will cause burn if it gets into contact, so depth is important. I then left this to sit for about a week, then planted some lettuce directly above that area. The difference in growth rates is very apparent. See image below.
Lettuce plants on the left grown above fish scrap mixture
Another experiment that I plan to carry out is to bury some more fish scraps, then plant a tree above it. I’ll compare its growth to other trees planted in “just” soil.
Molasses
Molasses is another useful soil amendment then can be applied in liquid form. Molasses is rich in calcium, magnesium, potassium, sulphur and other micronutrients. I happened to have a bucket full of molasses from about 10 years ago which I diluted (2 tablespoons per gallon of water), then applied directly to the soil. Although apparently, it can be sprayed directly on to leaves for faster nutrient absorption foliar feeding, just be sure to dilute the mixture more. In terms of acquiring molasses, your best bet would knowing someone, who knows someone who can get some from Portvale Sugar factory.
Vinasse
Vinasse is an interesting one, vinasse is a byproduct of rum production, and is what’s left behind after alcohol is extracted from the “wash” which is the fermented molasses mixture. I asked and was able to obtain a small bucket of vinasse from a local rum distillery. During the fermentation process, when yeast convert sugar to alcohol, the yeast are fed with the same nutrients that plants are fed with. Vinasse therefore contains these nutrients, nonfermented sugars and other organic compounds. Besides directly providing nutrients for the plants, vinasse also stimulates microbe growth in the soil which is beneficial for overall soil health. I only acquired limited quantities of vinasse so wasn’t able to experiment with it as much as I would’ve liked to. On the bright side, my plants weren’t negatively affected by its use.
All of these mulches, manures and amendments were obtained for free. Everywhere that we went, we were met with persons who were more than happy to help us out, from lending us shovels and bags without us asking, to helping us to collect seaweed, offering us pre-collected bags of manure or just simply being genuinely interested in what were doing. These experiences, among others, have shown that growing food can foster a sense of community and collectiveness. We genuinely hope that this post inspires you to go out there, meet some people and grow some food.
Bat Manure - just looks just like dirt
Sargassum - free and rich in nutrients
Chicken Manure - aged and full of wood chip bedding