Sustainable Farming

Science Magazine has an excellent overview of the challenges of optimizing food production for 9 Billion people over the next 40 years:

Producing more food from the same area of land while reducing the environmental impacts requires what has been called "sustainable intensification". In exactly the same way that yields can be increased with the use of existing technologies, many options currently exist to reduce negative externalities. Net reductions in some greenhouse gas emissions can potentially be achieved by changing agronomic practices, the adoption of integrated pest management methods, the integrated management of waste in livestock production, and the use of agroforestry. However, the effects of different agronomic practices on the full range of greenhouse gases can be very complex and may depend on the temporal and spatial scale of measurement. More research is required to allow a better assessment of competing policy options. Strategies such as zero or reduced tillage (the reduction in inversion ploughing), contour farming, mulches, and cover crops improve water and soil conservation, but they may not increase stocks of soil carbon or reduce emissions of nitrous oxide. Precision agriculture refers to a series of technologies that allow the application of water, nutrients, and pesticides only to the places and at the times they are required, thereby optimizing the use of inputs. Finally, agricultural land and water bodies used for aquaculture and fisheries can be managed in ways specifically designed to reduce negative impacts on biodiversity.

NYTimes has a good summary.

Permaculture design principles can help reach a lot of these goals.

Water is probably the most critical resource for successful farming. Lack of water is certainly bad in the short run, but improper use of water also has ill effects like increasing the salt content of the soil, making it unfarmable.

We have seen before that harvesting and managing water intelligently is one of the goals of Permaculture design. The two volumes of Brad Lancaster's Rainwater Harvesting for Drylands and Beyond are the most authoritative books on water harvesting that I have come across.

Volume 1

Volume 2

Lancaster has traveled the world in search of rainwater harvesting techniques, and refined the methods he found in the parched regions of Africa, India and elsewhere to create almost an encyclopedia of water harvesting and utilization methods. These are presented in a manner that's useful for the city dweller and the farmer alike.

The books are written in a very accessible language and have plenty of illustrations that show how each method works. In addition, the formulas for each method are also included, with examples, so that you can calculate the amount of water you can get. The books also contain plenty of practical tips and tricks that Lancaster has accumulated through his own experience as well as from others. Volume 1 contains an overview of the methods of water harvesting - small earthworks and water storage in cisterns etc, while volume 2 goes into deeper detail about earthworks.

Two of the most important points I learned from the books:

1. The soil is our best water reservoir.
2. What's important is not how much rain falls in an area, but how much stops in that area, and how it is used.

Recently, I wrote about the report from the Union of Concerned Scientists about the non-existent benefits of genetically modified crops:

Failure to Yield: Evaluating the Performance of Genetically Engineered Crops
... Despite 20 years of research and 13 years of commercialization, genetic engineering has failed to significantly increase U.S. crop yields. ...

Biotechnology crops, like the Roundup Ready seeds from Monsanto are exacerbating the problems they were supposed to solve:

As more acres of "Roundup Ready" crops are planted, the use of the pesticide has increased. The increased application has led some weeds to develop a resistance to glyphosate, the generic term for the chemical in Roundup. And, in turn, farmers have had to apply stronger doses of pesticide to kill the superweeds.

- Business Week, February 2008

Nonetheless, we tend to think of technological progress as a net positive. Is biotechnology the answer to the problems of mechanical and chemical technology of the past few decades?

Do we need biotechnology to feed the world?

We've seen that the world already produces enough food for everyone. Hunger is not a result of scarcity, but of inequitable distribution.

... The second fallacy is that genetic engineering boosts food production. Currently there are two principal types of biotechnology seeds in production: herbicide resistant and "pest" resistant. [Herbicide resistant crops] allow farmers to apply [Roundup] in ever greater amounts without killing the crops. ... [The "pest" resistant crop] produces its own insecticide.
...
genetically engineered seeds do not actually increase overall crop yields. ... [in] more than 8,200 field trials... Roundup ready seed produced fewer bushels of soybeans than similar natural varieties.

(The other troubling aspect of GM foods - the terminator seed technology, is currently under a de-facto ban. It is legally prohibited in India and Brazil.)

Is biotechnology safe?

• There is no overall reduction in pesticide use with genetically modified crops.
• GM foods brings its own pollution hazard - biological and genetic pollution. The harmful effects of GM organisms on natural ecosystems is well documented.
• Genes from modified organisms can spread to other organisms, with unpredictable consequences*.
• Biotechnology may bring new toxins and allergens into the human food supply.*

Biotechnology is expensive and inefficient:

Despite the billions of dollars spent creating transgenic organisms, biotechnology is yet to bring to market a single product that actually benefits consumers. Why should the public pay for this effort that offers no advantages, but increases risks?



* For example the StarLink corn recall: Wikipedia, New York Times, and more stories from the NYTimes.

Proponents of mega-farming often insist that highly mechanized, chemical intensive industrial agriculture produces food more effciently than small scale farming. I have already written about The Myth Of Large Farm Productivity, as well as the Energy Cost Of Food to show that this is false economically as well as energetically. Below are the facts against the proposed "efficiency" of mega-farming from the book Fatal Harvest: The Tragedy Of Industrial Agriculture:

... how does the "bigger is better" myth survive? ... because of a deeply flawed method of measuring farm "productivity" ... as the production per unit area of a single crop. ... If we are to compare accurately the productivity of small and large farms, we should use total agricultural output, balanced against total farm inputs and "externalities," rather than single crop yield as our measurement principle. 

...

Though the yield per unit area of one crop may be lower, the total output per unit area of small farms, often composed of more than a dozen crops and numerous animal products, is virtually always higher than that of larger farms. 

...

There is virtual consensus that large farms do not make as good use of even [farm labor and modern technology] because of management and labor problems inherent in large operations. Mid sized and many smaller farms come far closer to peak efficiency when these factors are calculated.

I'm off to the Permaculture Design Certificate Course in Molokai tomorrow. Blog updates will probably be infrequent for the next couple of weeks, but stay tuned on twitter.

You've probably heard that each calorie of food we eat takes more than one of fossil fuel calorie*:

All together the food-processing industry in the United States uses about ten calories of fossil-fuel energy for every calorie of food energy it produces. ... It takes thirty-five calories of fossil fuel to make a calorie of beef this way; sixty-eight to make one calorie of pork. - The Oil We Eat, Harper's Magazine

The following is from Table 1.1 in The Natural Way of Farming.

Farming Method	(Energy Output)/(Energy Input)
Large scale mechanized agriculture (ca. 1980)	2
Medium scale mechanized agriculture (ca. 1970)	4
Small scale mechanized agriculture (ca. 1960)	10
Farming with animals (ca. 1950)	20
Natural Farming	100-200

Now watch the presentation below by Saul Griffith about the components of our energy use, and the changes we need to make (including reduction in energy consumption and ramping up clean energy production) in the next 25 years to have any chance of controlling global warming. (If you're in a rush, skip the first 10 minutes or so to the -18.45 mark.)


It's pretty clear that highly mechanized industrial farming can not be a part of any long term scenario.


* See here and here for more in-depth discussion.

It's unbelievable that I have managed to not discuss guilds, the quintessential permaculture concept, for so long on this blog! We have discussed them indirectly by considering beneficial interdependence, sunlight harvesting, and complex systems with multifunctional components. But, without any more delay:

Simply put, a guild is a combination of plants and animals, where each plant or animal performs one or more beneficial functions. As these plants and animals are selected to fulfill each others' requirements, the system becomes almost entirely self-managing, requiring no external inputs and very little labor apart from harvesting.

I've found a couple of very well written descriptions of guilds, so let me just quote from them -

Stacia and Kristof Nordin of NeverendingFood write:

A good Permaculture guild generally has seven components:

• Food for us
• Food for the soil
• Diggers/Miners
• Ground Cover
• Climbers
• Supporters
• Protectors

Read their full description here.

Meg Howe and Graeme Young of Small Farm Permaculture and Sustainable Living describe guilds as:

A guild in Permaculture landscape design is a harmonious assembly of species (plant or animal) physically associated with a central plant or animal species to provide it with some benefit.

The range of benefits that can be derived from guild species include:

• Providing mulch
• Offering shelter and protection from frost, wind or sun
• Hosting predators
• Remove pest habitat
• Prey on or deter pests
• Killing root parasites or pests
• Providing nutrients
• Facilitating root penetration

Read their full description here.

Masanobu Fukuoka, in 'The Road Back to Nature':

I don't plow my fields, but I do sow clover. This is the easiest way there is to grow rice. With the arrival of spring, the clover grows thick and fast. I sow rice seed in this clover and later flood my field to weaken the clover and favor the rice. Then I drain the water and leave the field to itself.
...
A week or two before harvesting the rice, I take anywhere from about four to ten quarts of barley seed, place it in a basket, and scatter it over the field. This also takes about an hour. After the rice is harvested and threshed, I scatter the straw back over the field.
...
The straw and clover do more for the fertility of the soil than large tractors. So this is certainly not a primitive method of farming from the past. It may seem primitive if all you pay attention is the the word "no-till," but it is in fact a biological method of farming that uses plants and animals rather than heavy machinery. If you think of this as a means for raising soil fertility using microbes, as cultivation with plant roots, then it becomes the most advanced science.

(p217 and p223, 1987, Japan Publications Inc, New York*)

The goal of sustainable farming is not to farm in a primitive manner and be satisfied with low yields, but rather to get the highest possible yields with lowest energy and effort input, and to improve the local natural resources at the same time. To do this, we need to use natural components to create the most stable, productive, self managing systems and then avoid interfering with the natural processes.

* I will post an overview of 'The Road Back to Nature' soon. The excerpt above is quite atypical for the book, which, while certainly worth reading, primarily examines the philosophy of farming and modern lifestyles in Japan and Europe and America (with a healthy dose of 'get-off-my-lawn'!). Fukuoka's 'The Natural Way of Farming' is the one that has detailed information on natural farming techniques.

Also, when Fukuoka speaks of 'sowing' he means just scattering seeds on the field, rather than drilling them in the ground. The rice is also not transplanted from growing beds.

One of the major costs in conventional farming is the continuous manual or mechanical work required. In sustainable farming practices any unnecessary activity is consciously designed out. We've already seen how the functions of tilling and pest control are achieved by employing natural services, and how features of the land are employed to minimize labour and energy requirements.

In permaculture design, the zone system is used to minimize the effort required in managing and harvesting the farm.

On a sustainable farm with a lot of different plants and animals, some need more frequent attention and harvesting than others. These should be placed closer to the home to make it easier to visit them. Zones are a way of guiding this layout scheme:

Zone	Purpose	Need for Activity
0	Home
1	Leafy vegetables, herbs, strawberries, plant nursery, work area	Multiple times a day
2	Smaller fruit trees, fruit vegetables, beehives, chickens, compost bin	Once a day
3	Main crop for domestic consumption and sale, food forest	Once a week
4	Semi-wild foraging zone with large trees, mushrooms, firewood, grazing animals	Once a week
5	Protected natural area/wilderness for observation and learning only	Never

One of the few bits of knowledge I will remember forever from when I was studying to be a metallurgist* can be summarized** as:

The action is always at the interfaces.

The interfaces, or edges, between two different systems are an extremely important concept when setting up a sustainable agricultural system too. Due to the sudden change in system properties, interfaces are highly active zones, with energy and materials continuously in flux. Life takes advantage of these energy and material exchanges, and thrives far more easily at these discontinuities than in the more homogenous interior of an area. For example, the most biodiverse and productive sites in an ocean are near the shores as well as where cold and warm ocean currents meet. Comparatively, the open ocean is akin to the Sahara desert in terms of biodiversity and productivity.

In permaculture design, increasing the amount of edges is an important tool for maximizing the productivity of a farm. Specifically, ponds are designed with an irregular shape (as opposed to circular) to maximize the water's edge. Wooded and grassland areas are intermingled. Of course, since the biodiversity is high in any area, there are a lot of micro-interfaces where different organisms interact. All of this improves the resource efficiency and productivity of the designed ecosystem.

The corollary is reducing the interface area when you want to minimize material use and energy exchange. For example, spherical structures have the least surface areas for a given volume, and are thus the most energy efficient for heating and cooling***.

The edge effect isn't limited to the physical phenomenon**** - the most innovative scientific research happens in interdisciplinary fields (and of course, at the boundary between knowledge and ignorance). Some of the most interesting art and music and literature happens where two different cultures or ideologies meet.

So here's to the fringes. They make the world more exciting and productive!



* 1998-2002. Feels like lifetimes ago!

** For those who want a fuller explanation: The things we use every day (alloys, composites, etc) are made of different combinations of elements and compounds. In metals and alloys, the functional units of the material are crystallites (or grains). A huge fraction of the properties of the material (strength, ductility, conductivity, thermal properties) is attributable to the microstructure, and specificlly the grain boundaries. These discontinuities in the material are high energy sites, and influence the behavior of the material tremendously. Almost all of the thermal and mechanical treatments affect the properties of materials by increasing or decreasing the size, shape, distribution, and energy of the grain boundaries.

Control over the microstructure and boundaries is also very important for controlling the properties of polymers, ceramics, semiconductors and composites.

*** I also remember reading that ancient human dwellings progressed from round to rectangular as prosperity increased, and reverted to round shapes in times of prolonged scarcity. Can't find any references right now. Anyone?

**** Also read the post Some Thoughts on Edge on the Permaculture Reflections blog.

The third critical component in the natural world is sunlight. On conventional farms, orchards and agro-forests, there is usually only one primary plant species, and sometimes a secondary species, in any given area. Furthermore, a significant fraction of the land is directly exposed to sunlight either between plants or between harvesting and the next planting.

Contrast this with a natural forest, where there are multiple species of plants, each growing to a different height, and adapted to thrive in different intensities of sunlight. As a result, the ground in a mature forest is almost completely dark.

Permaculture design aim to replicate this phenomenon as much as possible on a farm, by creating a 'layered' system. The maximum harvesting of sunlight increases the total yield of the land. Considering that plants are the best solar harvesters we have till date, and that they provide a lot of indirect services along with the food or material harvested, it is imperative that we start employing solar intensive permaculture practices everywhere.

Also see:

• This previous post: Re-Solarizing Farming
• A post on another blog about a farm in Goa (India) that is "harvesting sunlight"

One of the major problems facing small and subsistence farmers is the quality of the land. The 'prime' agricultural land - large stretches of level ground with easy access to water - is already in the hands of larger and usually more financially capable farmers. Conversely, the poorest farmers cultivate marginal lands that have lower soil quality, that are often on hill slopes, and have rainfall as the only source of irrigation. Slash and burn agriculture is also often practiced on such marginal land, leading to a whole host of undesirable consequences.

However, most of the productivity of an ecosystem comes from the interactions of it's living components. This is especially true in tropical areas, where the temperature allows things to grow throughout the year. In a permaculture system, everything uses the outputs of something else. Nutrients are naturally integrated and then fully retained in the system. Over time, the inorganic soil serves primarily as a substrate, and all the necessary nutrients are obtained from the naturally composted biological matter on the top.

These beneficial interactions in a complex ecosystem, combined with small earthworks (swales and ponds) can convert any piece of land into a sustainable, productive, and profitable farm. The key is to plan a rich ecosystem that works with the layout of the land, and generates a harvest that satisfies the needs of the occupants.

An added bonus is that permaculture and natural farming practices work best without mechanization and do not require plowing. This is particularly beneficial for small farmers, who often go into debt to borrow farm machinary or even plow animals.

Here is an example of how seemingly barren land can be converted to a productive farm using permaculture principles:

As you can see, the knowledge of bringing barren lands back into production has been available for the past three decades. Unfortunately, the education and implementation has tremendously lagged behind the needs of subsistence farmers everywhere.

With this post, I am starting a series to explore the various aspects of sustainable land use. I still have a lot to learn, but a number of basic principles are becoming clear to me. In this series I plan to discuss the basic aspects of these interrelated concepts. I will discuss the complexities (and corrections!) in future posts.

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The goal of sustainable land management should be to create a habitable system that

• has very low running costs and labor requirements,
• provides for most of the needs of the people dependent on it,
  
• generates a substantial profit.

One of the key resources required for land to be productive is water. In the next few decades, water scarcity is only going to get worse.


Projected water shortage in the year 2050.
Most urban water harvesting schemes (rooftop collection and storage in dedicated reservoirs), though laudable, are expensive in the short term and neither sufficient nor sustainable in the long run.

To fully utilize the rainfall on a piece of land, it is necessary to

1. minimize water runoff
2. increase top soil moisture content and productive surface water
3. replenish deep underground water reservoirs

These water management principles were often utilized successfully to provide water for farming and urban communities. With the advent of modern engineering, we gave up these low cost, small scale techniques in favor of ever deeper bore wells, massive dams and long canals. Especially in the developing world, these mega projects are not only being built primarily for the benefit of large cities and industries, they have also suffered from corruption, social disruptions, massive delays and cost overruns, and most importantly, ineffectiveness.

The false sense of water security of these techniques spurred wasteful water use and indiscriminate water pollution. Conversely, the impending scarcity has brought us to the point where even the availability of water as a free resource is now under serious debate (even 007 himself got involved! ;).

In light of this evidence, probably the most effective (and cost effective) method is to implement water catchment and groundwater replenishment on the small scale. There are many ancient techniques to learn from and improve upon, but one of the simplest and most cost effective method is creating swales (also known as contour bunding).

Swales are simply long and shallow trenches dug on contour in a sloping landscape, with the dug out material piled on the lower end. This creates a barrier and reservoir for the water flowing down the slope. The water pooled in the trench slowly seeps into the ground, and also provides a stable source of water for plants planted on the mound. Especially in regions where rainfall is highly seasonal and/or irregular, swales are a very powerful way of slowing down the water so that it is available more uniformly throughout the year.


Due to their low cost and effectiveness, swales are an excellent way of beginning a permaculture food forest. These simple water features can be complemented by small interconnected ponds that hold water, percolate it slowly to replenish groundwater, and act as more sites for food production. This method also get rid of the false dichotomy of distinguishing between a 'catchment area' and a 'cultivation area', instead utilizing the available land for maximum productivity.

An excellent example of this approach is Sepp Holzer's* forty hectare mountainside farm in Austria that contains many productive ponds, as well as orchards and vegetable areas:


Do you know anyone that has a small farm or unproductive piece of land? Please tell them about this method of bringing the land back to maximum productivity with minimal investment. With the 3 billion new people joining us on the planet in the next forty years, the only way to for everyone to survive peacefully is to bring all the land back to high productivity without any resource depletion or pollution.

*You can also buy a DVD with three films about the various approaches Sepp Holzers has developed on his farm.

Farm Size versus Output in the United States, 1992

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Median Farm Size Category (Acres)	Average Gross Output ($/Acre)	Average Net Output ($/Acre)
4	7424	1400
27	1050	139
...	...	...
694	249	51
1364	191	39

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Since I briefly mentioned it a couple of weeks ago, I've been trying to get a handle on the inverse relationship between farm size and output. The effect has been observed in all regions of the world, and is consistent across all farm sizes (page 8, in the .pdf).* Looking through the 2007 US Agriculture Census, I found that the effect still exists, though the difference in output seems to be smaller than in the table above (perhaps due to a difference in methodology?). Data from Table 58. Summary by Size of Farm: 2007 (.pdf) According to the Food First policy brief, the high productivity on small farms in the developing world is due to:

1. Multiple cropping
2. Land use intensity
3. Output composition
4. Irrigation
5. Labor quality
6. Labor intensity
7. Input use
8. Resource use

(for detailed explanation of each, see page 7 in the .pdf) On the other hand, larger farms are typically cultivated as monocultures, usually yield a single crop per year, use heavy machinery and significant chemical inputs, and produce low value commodities. The environmental costs of large mechanized agriculture is a different issue altogether! Since in the developing world the vast majority of farms are small, and the availability of farm labor is high, it makes sense to improve the efficiency and profitability of these farms by switching gradually to natural farming methods which are even more profitable due to

• near zero input costs
• low labor requirement
• a diversity of high value (and organic) crops

The conservation and enrichment of local resources is of course an excellent added bonus. These will also make the ecosystems more resilient in the face of a fluctuating climate in the next few decades. * Browsing through current academic literature, I got the impression that among economists, this effect is viewed as somewhat of an artifact; i.e. economics research papers tend to explain the effect on the basis of inequalities (in labor etc.) between small and large farms, rather than as a real farm productivity difference. I have tried to get some clarification from professional economists, but haven't heard anything yet. If you have any opinions one way or another, please let me know.