As a relative newcomer to urban agronomy but a very experienced practitioner of cynicism, crypto-radicalism, and anti-everythingism, I knew already that the current corporate approach to commercial seed-and-plant selling was doomed and damned. It's a fact that many commercial seeds and plants are bred for appearance and not function, and that many of them are genetically designed to be infertile.
However, there is another practice in which I am highly experienced : that of doing things at the last minute. So, when I realized that planting season was upon me and that there was very little bee activity in my food-production area, I zoomed out and hastily bought a lot of started flowers in an attempt to bring th' bees over to where I wanted them. I spent about $75 (that's my strychnine money for a whole week) on snapdragons from Home Depot and marigolds and petunias from Whitfill's Nursery. I planted the suckers in my two containers and in sunken beds that I'd freshly dug, interspersed appropriately with my early food crops' seeds and transplants. I figured that since they'd been locally grown (all were marked with Arizona grow sites) that they'd be 'native' enough to be appropriate for my application. [dun dun duuum!]
Now, there is a big mass of weedy flowering plants on the other side of my yard that is always full of bees, so I figured that a few smart bees were likely to venture over to the new beds and find their tasty flower snax. [Why didn't I just plant my food crops closer to the existing flowers, you ask? It's because there's not enough shade / light filtration in that area for the crops I'm growing.]
I planted the things, and kept them well-watered with a buried soaker hose, and was ready for a bee essplosion!
So imagine my surprise when I watched bee after sleepy bee buzz around and sniff these new flowers, only to turn up their noses at them and pass by without landing! I was like WHAAAT
Meanwhile, the weedy flowering plants on the other side were budding more flowers and attracting more bees than ever. What the snake was wrong?
Here's what's wrong. Instead of planning ahead and planting native wildflowers earlier, I decided to cut corners and buy commerical garbage varieties of subspecies from other states that have nothing to do with my climate and also are unfamiliar to the local insect population (and being sold as ornamentals, may even be engineered to repel insects). See, bees and other benefical critters know to look for plants that grow normally in their area. And when they see and smell a native plant, they know it's good eatin'. But when they see a non-native blooms, they're like "well what is that" and sometimes they don't even recognize it as a potential nectar source. Even if they do recognize it as a flower, its alien smell will not likely entice the little beastie to munch. It's like if you put a big dish of palak paneer in front of a Wyoming cowboy. They'll just be like "now whut in tarnation is that racket" and move on.
So, I then spent all night doing what I should have done way earlier : I dug up some new sunken beds and sowed them with all-native desert wildflower seeds from http://NativeSeeds.org .
There are two lessons here. 1) Don't be lazy and then try to do everything in a quick-fix panic state. 2) Buy only native plant and flower varieties because your local beneficial insect population will know what to do with them.
Get your urban ag cranking in 2010 -- it's not too late. (38,773)
Soil is the most important aspect of any urban agriculture setup. It's the soil that nourishes the crops, and so it's important to understand its composition. As mentioned in the previous section, geologically speaking, soil is composed of sand, silt, clay, organic matter, water, and air. For effective food production, the soil must have enough sand for drainage, enough silt (a sediment often originating from glacial erosion), clay, and organic matter for nutrition, and be sufficiently moist and loose for planting. In high-quality soil, all these components are balanced to create a highly desirable soil type known as "humus." [not to be confused with "hummus," though I've eaten at some restaurants that don't seem to acknowledge the difference]
The chemical makeup of soil varies greatly by region and site, and influences the growing characteristics of what's planted there. Three of the most important elements present in soil and their roles are : - Nitrogen : helps green growth - Phosphorus : helps fruiting, flowering, and root development - Potassium : helps plants resist disease and drought Together, these three elements are called "NPK," and their concentrations in a soil are a key part of assessing site suitability. Other elements are also vital ro plant growth. In the Southwest United States, soils tend to be lacking in phosphorus, manganese, boron, and zinc. Liberal application of high-quality compost and mulch will generally solve these problems, though there are element-specific amendments available (see note below).
Beginning to Plant
It's vital to consider your local climate when planning your urban ag adventure. Arizonans are lucky in that the planting season there is year-round. Check out this planting calendar put together by the Phoenix Permaculture Guild, especially if you live in an arid climate : http://bit.ly/UIWwN
Regional climates are generally discussed in terms of "climate zones." Each "zone" indicates a specific "hardiness" level that plants are recommended to have for planting in that zone. Most commercial seeds are clearly labeled with zone recommendations. The greater Phoenix area is "zone 9b," for example; this corresponds with a "low desert" climate. It's wise to choose plants that are known to thrive in your climate zone -- native plants or plants from seed that are marked as OK for your zone (one zone "higher" is generally OK -- for example, zones 9 and 10 are usually OK in Phoenix). Note, however, that seeds for which your climate is on the outer range (for Phoenix, that'd be like a seed packed labeled "Zones 3 to 9") are not a very safe bet. It's best to pick seeds for which your climate fall in a moderate range ("Zones 6 through 9").
Seeds and Transplants
Most seeds take 7 to 14 days to germinate, and then they have to sprout and grow. 60 to 90 days of growing are then needed before the plant will fruit. Transplants, on the other hand, are already germinated and sprouted.
Transplants are sometimes faster to grow, but there are factors you'll want to consider before opting for transplants : After transplantation, "buffer time" is needed for the plant to acclimate itself to its new environment, as each transplantation diminishes its resistance to drought, disease, and pests for a time until the plant recovers from the transplantation "shock". Accounting for this, leafy greens generally take about 30 days to grow after transplantation; fruiting plants, 90 days; and root crops, more than 90 days.
The bottom line is that it's generally better to grow from seed, where you'll control the entire plant life cycle. If you must start a plant indoors, try starting seed in a container of the same soil into which it'll be transplanted (the soil from your planting bed) in order to minimize the "shock" effect.
Notes on planting in November, December, January in Phoenix :
If you have seed packets that say "plant after danger of frost," that means winter planting in Phoenix. This is the time to plant what other people call "early spring vegetables." If you hear a warning of frost (rare, but it happens), just cover the plants with lightweight material (newspaper, old bedsheets, etc) by nightfall, preferably over a simple frame or stake. This will slow heat loss and prevent frostbite. Be sure to remove the cover in the morning.
Asparagus (note : must grow for one full year before you eat it), lettuce, broccoli, cauliflower, potatoes, and other traditional "spring" crops are ideal to plant at this time. Seed packet instructions indicating "warm" climate mean Arizona fall through spring -- not summer.
Potatoes and root crops are best grown in loose, well-drained soil; mulch can be added to the soil to improve drainage. For potatoes, cut up the seed potatoes into one-inch pieces (this small cutting encourages them to grow quickly) , place the seed potato cutting eye-up in a depression you've made in the soil, and cover with a mound of mulchy soil. Keep the mound well-watered. When the flowers begin to bloom, you can start "robbing" new potatoes (don't take too many at once or the plant will wig out).
Notes on planting in February and March in Phoenix :
February and March are the times to plant what other people call "summer crops." These include tomotoes, peppers, okra, eggplant, melons, squash, and similar items. These need to germinate in cool 70-to-80-degree conditions and flower before the temperature hits 90 degrees. Plant early to encourage strong root systems, because a summer harvest demands roots that will bring in plenty of water and nutrients to support the plant. Don't plant late! Leave the plants in after harvest to keep weeds away and promote soil health.
A note on soil amendments :
In order to get your leached, weak soil up to snuff for planting food, you'll need to supplement its composition with "amendments" -- that is, additives. Now, many people use chemical fertilizers and such to boost productivity, but not only is that approach expensive, but it can have grave effects on your soil health in the long run and plants in the short run. Chemical fertilizers, which generally contain a lot of potassium and nitrogen, can degrade your soil's quality by increasing its salinity and raising its pH to high levels of alkalinity (these factors are worst in arid climates), and can lead to "fertilizer burn" (the symptom of which is leaf tips turnign yellow), which damages crops.
Therefore, it's best to avoid these chemical amendments altogether and stick with quality compost that you know is free of chemical rubbish. Compost will feed the crops with a broad menu of needed elements, at concentrations that are healthful for both the plants and the soil. Plan your urban agriculture setup well and with a mind toward growing region-appropriate crops, avoid monocropping in favor of rotational and companion planting, and apply sufficient compost, and you should never require the use of man-made chemical amendments.
In addition to traditional compost and compost tea, a very effective natural soil amendment is work castings -- that is, worm poo. This high-powered yet safe soil amendment is available commercially; you can also get yourself a "vermiculture" setup or "worm farm" and grow your own.
There are several other "natural" amendments which are viable for urban agronomy in cases where available compost and worm castings prove insufficient. For nitrogen boost, alfalfa meal is available. For phosphorus addition, rock and colloidal phosphates (ideally added to nitrogen inputs like manure at the composting stage, but also possible to spread directly on the soil) are options; it's advisable to check to be sure that these haven't been processed in ways that might leave harsh residues.
A note on hanging gardens :
Hanging gardens are believed to have been prevalent in Babylonian and Sumerian societies. Those were some of the hippest desert civilizations of their time, so they must have been onto something. In hanging garden arrangements, the plants actually grow upside-down. Ideal candidates for this method are tomatoes, eggplants, and similar crops. Hanging gardens create shade, double your available space, cools the environs, and is generally efficient. Old or dead trees are ideal platforms for hanging gardens, but rebar structures, chicken coops, and big fences serve very well. Terra cotta pots with a hole in the bottom can function as hanging planters.
Part 4 coming soon
The bulk of this information is drawn from the lecture series "Designing A Vegetable Garden" as presented by Heather Welch at the Phoenix Permaculture Guild (89,767)
Many sites are landscaped with rock and pavement. This creates what is known as the "heat island problem" -- that is, the rocks and paved elements absorb and hold solar heat, raising the temperature of the site, permitting little vegetation or evaporation. Another common landscape approach, xeriscaping, attempts to simulate a natural desert environment by using no deep-rooted plants, but only things like cactus and succulents. The problem with this approach is that it leads to erosion and a soil that is heavily leached and will not retain water; this is not conducive to growing food.
In contrast, permaculture-style landscaping that features a variety of rooted plants and water-managing features raises the water table and, though it requires more water input, may actually conserve water in the long run by cooling the site and creating more in-site moisture recycling (whereas xeriscaping creates a hotter, more arid environment by retaining little water). Plants cool a site, while rocks heat it up. So what's a person with rock on their site to do?
Don't remove the rock -- it's expensive and laborious to do so, and recall that 'using what's on hand' is a guiding permaculture principle. So, instead of removing the rock, redistribute it. Rock's heat-retaining characteristic is directly proportional to its surface area. Therefore, we want to arrange the rock in a way that minimizes the surface area and yet is useful.
The best way to do this is to use the rock on hand to create narrow, deep pathways around your planting areas such that the planting area will be sunken relative to to paths. This will help conserve your precious water -- the water will drain over and through the rock paths and be collected in the sunken beds. Sunken-bed agriculture has long been favored in desert Africa and other arid climates as a key water-management strategy. Repeat : sunken beds and raised paths are the best approach for growing food, especially in hot and arid climates. Raised beds will fry the roots of your crops when the sun beats on them.
Sidebar : the horror of Bermuda grass
Bermuda grass is a 'marginal' or 'fringe' plant -- it exists when land has begun to fail due to erosion and desiccation. It's an especially hardy species that is highly invasive, and is very difficult to control in an edibles-growing setup.
The 'conventional' approach to removing Bermuda grass is to use an herbicide, but smart people know that herbicides are poison and don't use them near their food crops. Instead, use the 'brute force' method : obtain a sod-cutter, "bobcat," or strong shovel (for the Calvinist) and remove the offending grass before planting. Attempt to scrape it off the top of your site. Due to its omnipresence and hardiness, it will continually stage comebacks, but this step will give you a head-start on it. If you're serious about keeping this hardy grass out of your planting beds, don't include removed Bermuda in your regular compost, as some of its seeds may survive the 140-degree temperature and come back to haunt your garden.
One tactic that has proved successful for keeping Bermuda grass at bay is the introduction of red clover, another 'marginal' species that is likewise invasive but has two advantages over Bermuda grass : 1) it attracts bees, which are vital for pollination of your crops, and 2) it smells better than Bermuda grass.
The 'Pre-Landscaped' problem
Many sites will already be landscaped with trees, shrubs, etc, before you arrive. This can be seen as an obstacle to your planting design, but the smart urban agronomist will incorporate existing green features into their plan. Rather than remove existing trees, remember that bees like trees and you need bees. Therefore, introduce gourds, grapes, and other hardy vines to grow up on and around the pre-existing features (including rocks of all sizes). This will create a photosynthesizing, water-producing heat barrier that requires little watering (because these thrive in dry conditions) is excellent at counteracting the effects of the urban "heat island."
Achieving microbial balance
Healthy plants are abetted by numerous symbiotic worms, insects, microbes and fungi living in the soil. Each type of helper organism lives in a certain "trophic level" -- that is, stratum -- of the soil. Microorganisms often move through fungal networks around plant roots to enhance crops' nutrient uptake. Helpful organisms come in several classes : - Bacteria - Fungi - Nematodes - Protozoa - Arthropods - Annileds - Birds and animals are also in symbiosis wit your crop, but we'll treat them elsewhere in this series.
Soil trophic levels are an important consideration in urban agriculture. It's important to work with the organisms in each level, rather than against them, to maximize yield and minimize the amount of work you have to do. The first rule of working with these trophic-level-dwellers is : 'don't upend, displace, and massacre them with a rototiller.'
To dig or not to dig?
Tilling displaces the organisms in each tropic level, disturbing them and causing them to die quickly. A few inches means a lot to microbes and tiny animals. The "no-till revolution" currently under way in urban agriculture allows the trophic levels to remain healthy and undisturbed by specifying that rather than digging and tilling. it's better to layer mulch and compost on top of existing levels to allow the natural action of symbiotic-critter level adjustment as these new mulch and compost layers are watered in and self-percolate.
The "traditional" method of bed preparation, "double-digging," is wherein soil is dug up from one end of the bed and moved to another end. This is disastrous for microbe and fungal colonies and, even worse, is very hard work.
The new method : "Lasagna gardening"
I wish that "Lasagna gardening" was a way to grow lasagnas, but alas, it's only a slang term for building up soil in a layered fashion and avoiding disturbance of the native soil's trophic levels. Here's how to do it :
1) Spray / soak the site liberally with compost tea or "effective microorganisms" to bacterially control pre-existing environmental toxiins 2)Put a layer of black-and-white (only) newspaper over the selected bed site. This is nontoxic and will discourage pre-existing weeds from erupting in your planting beds. (note : stay at least 3 inches away from trees ) 3) Layer equal thicknesses of mulch and compost on top of each other. Ideally, you want an ultimate planting depth that is equal to your root size; this is roughly the same as the height of the above-ground plant greens (hence the old saying "as above, as below"). This may seem daunting and silly, but after the first couple of seasons, the new material will be integrated with the original soil and the landscape will even out. 4) add new layers of mulch and compost after each harvest to continue enriching the site soil.
Kelp meal is a phosphorous-containing soil amendment that many have found to be beneficial to this process. However, those who live in landlocked areas may object to adding sea-based additives to their soil.
Coming soon : Part III
This information principally drawn from the lecture series "Designing a Vegetable Garden" as presented by Heather Welch in late 2008 courtesy of the Phoenix Permaculture Guild. (85,639)
Water management is key for success, especially in desert environments. One of the determining factors in water management is the overall slope of your site space. Observe where water flows and pools when it rains. The areas where water pools are ideal planting locations for root crops (carrots, beets, etc).
You can influence the flow of water by constructing "swales" along the elevation contour lines. "Swales" are geographical features that are constructed by digging along contour lines and mounding the removed soil on the lower-elevation side of the ditch, creating a depression and berm that guides water runoff. This method can be effective for minimizing water loss and guiding flow to where you need it - your planting beds with water-hungry crops.
Rainwater and 'greywater' harvesting are good ways to maximize the self-reliance of your urban agriculture project. Rainwater harvesting requires a well-designed gutter / catchment system and collection barrel. When deciding how to apply your harvested rainwater, be aware that if your house has asphalt / tar / composition shingles, the roof runoff will contain toxic residues from the shingles. Therefore, you don't want water that runs of an asphalt roof to be used on your vegetables; it's probably OK to use on trees and anything you don't eat (though there's some argument about whether you should use it on trees that bear edibles -- see note on toxin concentrations in fruit). Water that runs off tile, tin, concrete, ceramic, wood shingle, or other non-volatile roofing materials is kosher for all plant uses.
'Greywater' is relatively uncontaminated water that's been used once in your home - for example, to wash clothing or the dishes. By using biodegradeable, nontoxic detergents, the urban agronomist can collect that water -- which is quite a lot - and re-use it directly on trees or and non-edible plants. You'll need to plan how best to get the greywater from its source (e.g., the clotheswasher) to the destination (e.g, your orange tree). For example, a hose can be run directly from the clothes washer to the orchard or collection barrel; catchments and barrels can be used to store greywater before use. Note that since greywater can harbor bacteria, it should not be stored for more than 24 hours before use (unless cured by UV rays). For collecting greywater from the kitchen and bathroom sinks, the simplest way is to simply collect the water in bowls and decant it into a bucket to take outside; you can also do minor plumbing alterations to make it easier. There are numerous books and commercially-available systems on the market with more detail about how to install greywater systems in the home; be sure to consult local laws governing greywater before starting on the project.
Some municipalities offer irrigation as a city service. This provides very cheap and plentiful water, sufficient to grow even the thirstiest crops. The downside to this convenience is that irrigation always brings with it numerous seeds (such as Bermuda grass) and insects. Take care to be on the lookout for invasive species when using municipal irrigation. Avoid placing plants directly in front of the irrigation channel to avoid damage from water movement.
When using forced city water -- that is, tap water -- there are several concerns to bear in mind. The most crucial is that tap water is chlorinated and fluoridated; left untreated, it'll kill vital garden bacteria and fungal microrhizome 'residents.' If you have no bacteria, you'll have no worms, and no worms spells doom for vegetable gardens. Without symbiotic fungi, your plant roots won't be able to take in vital nutrients from the soil. Therefore, if you use tap water, install a filter system that's designed to eliminate chlorine and fluoride contamination. If a commercial filtration system is beyond reach, these harmful elements will also evaporate if you leave the water in an open barrel or bucket for 24 hours or more. It's been hypothesized that toxins in water are concentrated in plant tissue to a factor of ten, so prenez garde!
Sun and shade
As important as water management is the practice of solar planning. It's essential to plan your plantings with a mind to the patterns of the sun on your site and the needs / tolerances of your crops. Plants can be sunburned just like animals can.
Pay special attention to summer sun patterns. In arid climates especially, avoid planting vegetables in places where they'll receive direct solar radiation (cactus and desert succulents are OK in direct summer sun). This is one of the reasons why it's desirable to create a multi-tiered "canopy" with trees or trellised sun-tolerant vines providing shade for edibles below. Creating such a canopy system improves not only the soil and plant health, but also site air quality.
You'll note that the sun pattern in your space will vary considerably between summer (the sun will be directly overhead) and winter (sun will come in at more of an angle).
The best spots for planting on your site are those that are in partial shade in the winter sun pattern. Determine your sun patterns by carefully observing the shade patterns as they shift throughout a day. You can approximate the patterns of whatever season it isn't by drawing a bird's-eye-view map of the site, putting objects on it to represent shading structures (for example, a tissue box for the house and saltshakers for trees) and moving a bright flashlight over the model, imitating the sun's sweep, to see how the shade patterns move.
The ideal type of shade is "filtered shade" -- that is, shade that doesn't completely obscure the sun. For this, trees with smaller leaves such as mesquite, palo verde, and palo brea are ideal. These types of trees are also "nitrogen-fixing" plants -- that is, they take elemental nitrogen from the atmosphere and convert it into nitrogen compounds in soil that can be used by other nearby plants. Note : if you have a dead tree on the site, don't root it out - introduce a trellising vine like grapes to grow up it and provide shade. Using what you've got on hand -- like pre-existing structures -- is a key permaculture principle.
Understanding microclimates
Microclimates are local variations within a regional climate. For example, the Phoenix area has an overall climate that is hot and arid. However, variations in elevation and airflow patterns make the North East section of the valley significantly cooler and more verdant than the southwest section. The urban center is hotter than the surrounding areas due to to high concentration of heat-retaining structures and pavement. Likewise, there are microclimates within individual sites. It's a good idea to walk around the site in he middle of the night, making notes as differences in temperature, humidity, and wind movement are perceived. These microclimates will influence the planting layout.
Soil : analysis and composition :
Soil is composed of sand, silt, clay, organic matter, air, and water. It's what plants grow in, and is ultimately the source of all food. It's important to think about and analyze the soil on any planting site.
Typical Arizona soil is heavy with caliche -- a mixture of clay with mica and montmorillonite particles. The clay and mica particles lay flat against each other, making for poor permeability and drainage. It's hard to break up and very challenging to grow in. The type of soil that's ideal for planting is called "loam" -- an equal balance of all particle types and sizes with plenty of organic matter. This soil type is very "friable" -- that is, easy to plant in -- and is nutritious for nearly all plant types. Any soil type can be made to take on the characteristics of loam with the addition of time and natural soil amendments -- compost and mulch. Never use gypsum to break up clay deposits, as it will make soil terribly alkaline.
The site soil should be tested for pH before the project is started. A pH between 6.8 and 7.5 is considered to be neutral and good for most plants; desert soils tend to be alkaline (~8.5 pH); some soils are acidic with a lower pH. The correct way to manage soil pH that's too high or too low is to add plenty of compost, which will help neutralize the overall pH. Any nursery can test the site soil for pH.
If you believe that your site may be heavily contaminated with industrial toxins, motor oil, pesticides, or other hideous stuff, many major universities (such as U of A) will test your soil for poisons (for a significant fee). If you find that your soil is contaminated, but still want to plant, you can attempt to "bioremediate" it using liberal amounts of compost tea and / or so-called "Effective Microorganisms."
Note : never use raw manure or fecal material directly on your soil, no matter what you hear-- it will introduce pathogens and can potentially cause 'nitrogen burn' in crops. Compost all manure before applying to your soil.
How to determine your soil's composition : This is easy. Just fill a lidded jar halfway with the soil to be tested (it's recommended to test multiple parts of your site), fill rest of jar with water, shake it up well, and leave it to settle for 48 hours. The sample will then separate into layers and reveal its composition. The bottom layer is sand, the middle layer is silt, the next and lightest-colored layer is clay, and floating on top is organic matter. The composition of your soil samples will tell you what amendments should be added to optimize the soil's friability.
If clay is present in excess, coarse compost or mulch can be added to help make the soil more permeable over time. Clay does have redeeming characteristics -- for example, it's rich in plant nutrients, as is silt. If your soil is sandy, that's not necessarily a bad thing -- sand is vital for good drainage. Just add plenty of finished compost to amplify the nutrient value. If your soil is weak in organic material, add mulch and compost (the more, the better).
Getting started
A good plan for starting your urban agronomy adventure is to pick the best-shaded, well-watered spot on the site and create a 4 by 8 foot bed (planting your favorite native food crops using the companion-planting strategy -- more on that later). This functional size is manageable for the neophyte and is modular, so that your planting beds can be easily added together or rearranged. Once you have success in the 4x8 bed, create more. A key permaculture principle to apply here is "start small, get big."
Basic tools
The basic tools you'll want to embark on your planting experiment are : - Gloves - Shovel - Rake - Hoe - Wheelbarrow - Rebar stakes are useful for many things including water and air management - Compost and compost sifter - Velcro for plant ties
The bulk of this information was drawn from the lecture series "Designing a Vegetable Garden" as presented by Heather Welch, November 2008. Part 2 to follow (83,909)
I was looking over the stats for this site, and apparently it gives me a list of things people searched for to get here. I see here that a surprising number of people turn to us for information about why their compost is heating up, and what that has to do with thermodynamics.
That's really weird, but I happen to know the answer (is that weird too? I don't know). I'm supposed to be studying hundreds of pages of pathology notes at the moment, but I think I can procrastinate just a little bit longer to answer this incredibly important question.
Every chemical reaction can either require energy or give off energy. For instance, making carbon dioxide and water into sugar and oxygen requires energy (when plants do this, they use sunlight and it's called "photosynthesis"). Most other organisms besides plants turn the oxygen and sugar created by plants back into carbon dioxide and water, which actually gives off energy.
Each process is long and convoluted, but the laws of thermodynamics state, among other things, that the conversion of energy from one form to another is never 100%. While none of the energy is ever destroyed, some of the energy gets misdirected into heat. This is why a perpetual motion machine--a machine that moves constantly without stopping or requiring any outside energy for all eternity--is impossible. Some of the energy of the machine will be shunted constantly into undesirable heat, which the thermodynamic laws' authors call "entropy."
So how does this relate back to compost? All living things which eat sugar are going to convert that sugar into energy used to power other chemical reactions. That energy is packed into a little molecule-sized battery known as ATP. That ATP plugs into other molecular machines (enzymes), dumps its energy into them, and then ejects. Some of the energy that goes into forming ATP and in the process of dumping ATP's stored energy into those machines turns into particles which fly out in all directions (infa-red photons AKA "heat"). Some warmth is necessary to keep atoms moving around so life can keep on going, but much of the heat created by the organisms is unnecessary, and simply due to the impossibility of a 100% exchange of energy from one form to another.
The bacteria and/or fungii are unlocking the energy stored in the sugar and other molecules of the compost and using it to build other molecules. Some of the energy is needlessly bled off, creating heat. They don't really want to be doing this, but they can't help it, because it's actually impossible due to avoid, which is what the second law of thermodynamics states.
If you have a problem with your compost heating up, you're kind of SOL. These little bugs have don't like it either, but if millions of years of evolution can't solve the problem, you definitely can't.
Update: Hank has pointed out that the heat created by bacteria in compost actually ends up killing them! This is apparently a necessary part of the composting process. Shows what little I know about gardening.
As a side note, I can actually think of one living thing that creates heat for the sake of creating heat. Infants are born with small patches of special fat cells on their neck and other places. These fat patches are different from other fat cells, and when looking at them you can actually see that they are brown (fat is usually yellow or beige, this is Brown Fat). Like most cells, Brown Fat cells have mitochondria, which are little chemical converting doohickeys that float around in the cell and convert whatever usable crap floats into them. The mitochondria in Brown Fat cells, however, are defective by design. They basically take the complex chemical conversion system and "short it out." Chemical "A" turns to B, B and B is thrown away when normally it would be used to make chemical C. The lack of chemical C tells the mitochondria to turn more A into B, which creates a lot of extraneous heat. In the same way you can short out a battery by connecting the positive and negative poles together, these fat cells short out this chemical system and create heat (also like shorting a battery). It's thought that these fat cells help keep the newborn's brain warm when it is most vulnerable, which is the first few days after birth. By the end of those few days, all the fat in the brown fat cells is burned and they die.
Well I hope this explains all that for you strange Googlers. (48,354)
Like Jack in 'Sideways,' we're an infant - at least as regards our ability to look after ourselves in a real and substantial way. If we're going to get our sovereignty back, we like the bambino must first learn how to feed ourselves.
Food matters, big time. Most crucially, it's what we choose to use as fuel and building material for our bodies. Nearly as importantly, it's a major component of our cultural and social reality. No factor is as crucial to our bodily and mental health as food security -- reliable access to nutritious food.
Food can be transformed in numerous ways, but ultimately all food comes from the ground -- the soil. The food chain starts with that which grows in the ground, and much what we eat comes directly from the dirt. Everything that is in our food was once in the soil, chemically speaking. It follows, then, that anything we put in our soil will end up in our food.
This last fact, coupled with expense and ecological factors, makes plain that for best health and nutrition, we want our soil to be free of poisons. Poisons, as we understand them here, include among other things all chemical and synthetic toxins such as pesticides, herbicides, and artificial fertilizers.
How, though, are we to raise an adequate amount of food for serious self-support without the use of 'fertilizers.' especially in harsh climates?
Organic, self-produced compost is the answer. Compost that we make ourselves, controlling all inputs and results, gives our crops the nutrients they need in abundance, while freeing us from chemical residues created by commercial fertilizers. Compost is so effective at increasing crop yield that it has earned the sobriquet ‘brown gold.’
With a properly-implemented composting plan, we can raise really substantial amounts of our own food without much delay. Here's the scoop, starting with a brief overview and FAQ :
- What is compost and what benefits does it provide? -
-Compost is organic matter that has fully decomposed, becoming a uniform dark, microbially-active but non-toxic, soil component material that is much like the soil type known as 'humus.'
-Compost, when added to soil, acts as an addition of live matter that promotes plant growth.
-Composting recycles spent plants back to the soil
-Compost, with its active microbe communities, attracts beneficial worms that aerate the soil, promoting root growth and good water drainage
-Compost buffers excessive sodium content -- a common problem in many arid and depleted regions
-Compost provides high-density nutrients to plants
-Compost protects plant root systems from heat and cold, and fortifies entire plant against the elements by means of better nutrition
-This same nutrition, combined with the microbial community it brings and the underground ecosystem is engenders, protects crops from disease.
-Compost application is very effective at balancing the pH of soil, quickly bringing it to the 6.4 to 6.8 range that is ideal for cultivation of food. This is of great value in areas with harsh, alkali soil, such as deserts.
-The application of sufficient compost completely eliminates the need to till the soil. Eliminating tilling altogether dramatically improves soil health.
- Are mulch and compost the same thing?
- -No. Mulch is relatively large-sized chunks of relatively dry organic material (for example, wood chips) whose primary functions are to improve water drainage, to protect soil from harsh sun and cold, and to choke out weeds by denying them sun. Its secondary function is to help clay-heavy soils become more permeable to root systems, which occurs as mulch breaks down. Some mulch is partially decomposed when delivered, some is not. Mulch, added to a compost batch as a ‘carbon input’, will become compost over time. Note that there exist products known as ‘plastic mulch,’ which are bits of plastic marketed for use as mulch. These are harmful to your growing environment, will not break down, and should be avoided. Beware also of mulch that may be covered in insecticides, such as commercial landscaping byproducts.
- What tools do we need to start composting right now? -
-A bucket for the compost material
-A shovel to spread and stir the compost
-A pair of clippers for getting raw materials like branches down to compostable size
-A long-stemmed thermometer ("compost thermometer")
-Compost screen -- you can make this yourself in minutes
-A dust mask or respirator
-Other useful but nonessential equipment includes a wheelbarrow, chipper / shredder, blender, gloves both rubber and leather, and pitchfork.
-What are the popular methods of composting?
There are three major methods of composting. Each requires a correct balance of raw materials (more on this later), regular turning / agitation, and monitoring of the internal temperature of the compost as it breaks down.
1) The Pile Method : This is where you simply layer your raw organic materials into a pile in a specified place and allow it to decompose in the open. This method is popular but can be susceptible to weed germination and pests within the pile, and can be unsightly.
2) The Bin Method : Construct a wooden bin from scrap wood, old pallets, or drill aeration holes in a 30 gallon rubbish can. This method offers more control than the pile method.
3) The 'In-Vessel' Method : where a closed, rotating vessel known as a 'Compost Tumbler' or 'Compost Drum' is used. These can be bought commercially or made with some effort. The advantages of this method are considerable convenience of agitation and material addition, and nearly complete protection from weeds and pests.
-What raw materials should I use?
-We need a proper ratio of two classes of materials in our compost :
1) "Carbon inputs" - this means dried brown material like dry leaves, wood chips, and clippings
2) "Nitrogen inputs" - this means green and / or moist material such as green plant and grass waste, discarded fruit and vegetable material, coffee grounds, and manure
NOTE : the proper ratio is 25 carbon to 1 nitrogen by weight, which works out in practice to about 1 : 1 (half and half) by volume.
-What must I avoid composting for use on food crops?
-Dog, cat, and other predator manure -- these can carry persistent pathogens
-Castor and oleander products -- these materials contain persistent toxins
-Pine needles in high quantity -- these contain a persistent natural herbicide.
-So what manure is OK to compost?
-Cow (as opposed to steer) manure is best, and has properties that in practice appear to protect against certain plant diseases, such as dollar spot disease and sweet basil wilt.
-If cow manure is unavailable, look for horse manure. Horse manure is available from stables and, as a bonus, comes with straw (so you get both nitrogen and carbon inputs from one source)
-Avoid steer manure - this contains harmful amounts of sodium -- this includes all commercial manures
-Be aware that if your manure comes from animals which are fed non-organic diets and / or treated with chemicals, certain of these residues may remain in your compost. See addendum on bioremediation for details on how to mitigate this factor.
- What exactly is going on in my compost bin?
-What's happening is the biological process of decomposition, which converts solid and liquid waste into a stable, humus-like product. This is acheived through the action of bacteria. There are three types of bacteria :
-Aerobic : bacteria that need oxygen to live
-Anaerobic : bacteria that can thrive without oxygen - such as those inside your stomach
-Facultative : bacteria which can adapt to either condition
We want to encourage the action and propagation of aerobic bacteria in our compost, because this type of bacteria is best at controlling the odors of decomposition. This is done by regular agitation (mixing) of the compost as it decomposes.
-Why do I need to take the temperature of my compost every day?
-There are two reasons for this :
1) To be sure that your compost is achieving what is known as the 'thermophilic temperature range' - 114 to 160 Fahrenheit degrees. This is essential for the elimination of pathogens, pests, and weed seeds from your compost. If your compost doesn't get this hot at its core, it's not properly decomposing.
2) To judge when the compost is 'done' -- this is when it returns to the low end of a temperature bell curve.
-The heat described here is caused by the action of living microbes as they go about consuming and processing the composted material.
-If your compost isn’t getting into the proper heat range, that means that your carbon / nitrogen (“C/N”) balance is off target.
Understanding Carbon / Nitrogen Ratio and Temperature
If your C/N ratio isn’t close to the recommended 25:1 (by weight) mark, your compost will not break down properly. If there is too much carbon input in the mix, you will see very slow decomposition rates. If there is too much nitrogen input, you will detect an ammonia smell coming from your compost container. Note : Compost should not create unpleasant odors! If your compost stinks, mix it up and add more carbon inputs.
The temperature of your compost will rise and fall on a bell curve over the processing time of the batch. From the starting temperature, it should gradually climb to 114 to 160 Fahrenheit, and then begin a gradual decline back to near the starting temperature. Because we rely on the action of aerobic bacteria for this progress, it is important to aerate (turn) the compost regularly, up to once per day but at least twice a week. This is how we introduce oxygen to the aerobic organisms that need it. If you are using the pile or bin method, use your shovel or pitchfork to turn each batch; if you have a compost tumbler, you simply turn the crank.
Be sure to stick the stem of your stainless-steel compost thermometer into the very center of your compost batch to ensure an accurate reading, and take the temperature every day.
It is important to keep the average size of the particles in your compost batch small to encourage speedy decomposition – this is where the chipper/shredder (balance horsepower with cost according to your needs when selecting these) and blender can come in handy. The smaller your starting particles are, the more easily they will be processed by the bacterial action. Smaller particles are also easier to store – note that you can store carbon and nitrogen inputs separately in plastic rubbish containers for future use, and it is wise to do so.
In addition to being properly oxygenated, each compost batch must be properly hydrated. The proper moisture level of the compost batch should approximate that of a wrung-out sponge; there should be no standing water. Standing water will attract pests and insects – if you detect excess water in your compost batch, add more dry inputs. Typical sources for moisture in your compost will be green nitrogen inputs such as plant trimmings, household waste (non-animal-product food scraps) that has been blended with water, and ‘compost tea,’ the making of which is described in the addendum.
You can add water directly as necessary, being careful not to overwater, but beware! Do not use water direct from a tap or garden hose unless you have a whole-house filtration system. The chlorine added to municipal water will quickly kill the bacteria you need for successful compost and leave you with a soggy, inactive waste mass. Chlorine also combines with other compounds in compost to produce harmful methane molecules. If you have no filtration system available, you can put water in a watering can and allow it to sit outside for 24 hours before using it – this will cause all the chlorine in the water to evaporate. De-chlorinating filters are also available, which attach to faucets and hoses.
When the compost batch returns to the bottom of the bell curve, decomposition is complete and the batch is ready to use. Take care! If you do not wait until the compost is ‘done’ and at the bottom of the curve (that is, until the bacteria are done processing), the active and voracious bacteria will eat the seedlings you’ve planted. Waiting until your compost has completed its thermal bell curve is known as ‘resting to maturity.’ A well-executed, efficient compost batch will go from start to finish in about two weeks; less efficient batches will take longer.
Understanding the Role of Manure
Manure can be a helpful and inexpensive addition to your compost batch. It’s important to understand the nature and role of manure before deploying it, however, to avoid potential serious problems.
-Manure is animal waste. As noted above, only cow (not steer or commercial) and horse manure are acceptable among mammal wastes. Chicken and other bird manure is also good for composting. Cow manure has properties as an antifungal compost additive and a unique complement of nutrients, and is therefore widely sought.
-Rule #1 : Never apply raw manure directly to your soil. This is a grave error made by many, from commercial farms to home gardeners. Direct application of raw manure to soil has the following negative effects :
-Raw manure contains numerous pathogens that will be passed on to your crop – potentially a deadly situation in the case of vegetables like leafy greens that grow low to the earth. One has only to recall the recent salmonella outbreaks to understand the gravity of this problem.
-Raw manure contains weed seeds that you likely do not want to introduce into your growing environment.
-Raw manure contains high concentrations of nitrogen that can cause ‘nitrogen burn,’ wherein the plant uptakes a harmful amount of the element and suffers what is in effect chemical burn, and ‘junkie plant syndrome,’ wherein a plant will get ‘high’ after the first application of raw manure, growing rapidly, and then ‘crash,’ wearing out and withering rapidly before producing a substantial harvest. Both of these effects substantially reduce your yield and biologically damage your plants.
Worms and Composting
Worms are basic to healthy soil. Their action is to consume microbes and small material and leave behind nutrient-rich ‘castings’ – this is not considered to be raw manure and can be applied directly to soil if desired. When in soil, the worms also aerate the ground, allowing roots to more easily penetrate (essential in areas like Arizona with hard clay-rich soil) and water to drain and distribute. Worms from the nematode and annelid families are both needed for healthy soil, and annelids such as nightcrawlers can be cultivated. Commercial ‘worm hotels’ are offered by many companies, and a side-science of ‘vermiculture’ has grown up around this activity. Generally speaking, vermiculture involves growing many worms at once, in a contained system that allows their castings to be easily obtained (usually in trays). These worms can be added to the soil to continue their work.
It is possible to attract considerable numbers of worms to even arid soils without the need for expensive vermiculture set-ups. This is done through the practice of ‘cold composting.’
Cold composting is the addition of blended, hydrated carbon and nitrogen inputs, most often in the form of non-animal kitchen wastes blended with water, directly into the soil without the step of allowing them to first decompose through microbial action. These blended wastes are put in a shallow depression dug in the ground and then covered with soil, each application in a different spot. Worms are attracted to this ‘cold compost’ from far beneath the surface of the ground and will quickly make their way to the upper soil layers to consume this treat, bringing with them all their benefits of aeration and castings. When cold composting, remember to clip all scraps to a small size before blending, and to dig a new hole for each batch of cold compost. This can be done daily, with great effect coming from little effort.
Screening Your Compost
In order to maximize the effectiveness of your composting effort, make or buy a compost screen and use it with a wheelbarrow. The way that this is done is by building a simple wooden frame of two-by-fours to a size that will sit closely in the opening of your wheelbarrow, securing half-inch steel mesh across the frame, and shaking and raking your compost through it with a trowel before applying compost to your cultivation area. The chunks that don’t fall through the screen into your wheelbarrow are not fully broken down and can be added back to your next compost batch to ‘finish.’ A finish of boiled linseed oil will improve the durability of your compost screen. It’s also possible to build a rotary screen by cutting out panels from a large plastic bucket, covering the panels with screen, and adding a loading gate and hand crank similar to those on a compost tumbler. Once built, this method makes for rapid screening.
Applying compost
Compost should be applied directly to your planting beds before seeding, and then regularly around the crop rows. There can never be too much compost in your cultivation area, so apply liberally. If you manage to generate more compost than you can use in one application, it will keep for a long time in a covered plastic barrel or bin.
Composting and your climate
Those of us who live in climates that are warm year-round can enjoy an uninterrupted composting cycle throughout the year. Those who live where cold temperatures are common and freezing often occurs, however, will be faced with a compost cycle limited by the seasons. It does no harm to leave compost and compost inputs out in the cold, but it simply won’t produce finished product until it’s warm enough to achieve the 114-160 degree temperature range at its core.
Compost will not decompose much during the wintery months in temperate and colder zones. The producer has a choice to either :
1) Compost only when it is warm enough to do so outside
2) Move the composting process indoors, such as in a garage or unused room, during the winter.
Since properly-done composting does not generate offensive odors, we advocate the practice of indoor composting in cold winters. This can either provide a substantial store of compost to be applied in the spring, or provide compost for continuing indoor container gardening. Since compost will keep for months, there is no need to worry about an apparent excess.
Conclusion and end notes
Composting is the way for us to rapidly take control of our food supply by greatly increasing our crop yield and re-using our food waste. As we’ll see in better detail later in this series, the best way for the new food raiser to get a jumpstart is to apply compost and mulch in layers of equal depth directly to the crop area with no tilling, and to plant directly in this, according to season. With good compost, costly and ultimately damaging chemical fertilizers are made obsolete, along with tiresome and time-consuming digging and tilling. With the knowledge presented here and the right inputs, the novice food producer can begin planting within a few short weeks, and can start producing poison-free food and look forward to an expeditious trip down the road to self-reliance. It will be beneficial to the new food raiser to record the data about their endeavors, such as inputs used, daily temperatures, and total length of processing for each batch; in this way, one can learn the most effective methods for their own environs and resources. More information about the actual planting and cultivation process will be presented as this series unfolds. For now, begin collecting inputs and start that compost batch!
Addendum : Bioremediation and ‘Compost Tea’
Most people in the industrialized world live on land that has been subject to the ravages of commercial urban horticulture (landscaping, which tends to use a lot of insecticides and herbicides) or ‘factory farming’ (which also uses chemical fertilizers). What goes into your soil goes into your food, and subsequently into your body when you eat that food. Therefore, the presence of these industrial residues, along with whatever unintentional pollution may exist in your soil (for example, motor oil dumping, waste from mills that has seeped into soil, etc) is troubling for the food raiser.
One way to partially mitigate the effects of these toxins that are in your soil through no fault of your own is to employ a strategy known as ‘bioremediation.’ This is a term that means the use of microorganisms to neutralize chemical toxins – a biological remedy. The technique is used extensively by governments in the cleanup of ecological disasters like oil spills, and can be employed by the self-maintaining food producer as well.
The basic idea is to identify microbes that consume toxins, cultivate them in quantity, and spread a liquid solution containing them across the area that is affected by chemical pollution. The microbes work through the soil, consuming and neutralizing the toxic chemicals.
The government uses classified blends of microbes to achieve its ends, but the private citizen has other options available. The two most popular are the purchase of commercial ‘effective microorganisms’ and the making of ‘compost tea.’
‘Effective microorganisms’ is a trademarked term that generally refers to a specific commercial product, available for sale online. This product is a suspension of a proprietary blend of microbes in a water and molasses solution. The manufacturer contends that the organisms offered in this product can ‘bioremediate’ a wide range of toxins. If one chooses to buy this product, one need buy it only once – these microbes are like yeast and can be propagated indefinitely by adding more molasses and water to the solution as it’s used. Also, we recommend ignoring the ‘expiration’ or ‘use by’ dates on the package, for the same reason. Unless left in the sun or otherwise killed, these organisms will keep and reproduce indefinitely, similar to the behavior of a sourdough starter. The commercial preparation is diluted with water and sprayed directly onto the affected soil.
‘Compost tea,’ simply, is what is produced when a cloth bag of compost is suspended in a barrel of filtered water and ‘brewed’ for 48 hours, preferably in the sun. The resulting liquid is certainly rich in nutrients and helpful bacteria and can be added as an enriching amendment directly to crop areas or compost batches. Proponents of this ‘tea’ often employ it as a bioremediation tool, claiming that the microbes present in the average compost tea batch are similar to those in the commercial preparation, work effectively to neutralize toxins, and can be produced by the grower at little cost (whereas the commercial preparation is very costly).
More research into bioremediation of agricultural soil, particularly for the urban food producer, is urgently needed. Better and more widely-informed science on this subject will go a long way in helping the food producers large and small achieve higher yields of less-toxic crops.
Whichever method you choose, it is wise for anyone growing their own food to apply one of these preparations to their soil before beginning the initial growing process. In addition, if using inputs from non-organic or non-poison-free sources such as non-organic cow / horse manure, or grass clippings and tree trimmings from around the neighborhood, it is advisable to add bioremediation solutions to your compost container to neutralize toxic residues. Unless you have a full laboratory at your disposal, you won’t be able to truly gauge the effectiveness of your bioremediation efforts. Therefore, it’s best to use only organic inputs for your compost when you have the option. There is a mounting body of anecdotal evidence, however, that these solutions can be effective in rehabilitating land tainted by chemical inputs and polluting residues, making food grown in that soil less toxic to consume. There will be more information presented later in this series about the concentration of soil toxins within the food produced. Suffice to say that bioremediation of our soil before planting is a low-cost bet that it makes sense to take.
Acknowledgement : A large part of the information presented here is taken from the lecture “Composting in the Southwest Desert,” by master gardener and writer Jim Muir, as presented on 11-13-2008. (57,923)
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