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Guidelines for Semi-arid Sira, India

‘Arid Climate’ Articles at Permaculture Reflections

September 11, 2014 by Douglas Barnes 2 Comments

You can tell the season a permaculturist is in by the frequency of blog posts they produce. Because it has been a while, I’ll post a response to some questions sent in to my by a reader near Sira, India.

 I plan to build rainwater harvesting & groundwater recharge structures, and leave the land undisturbed for few years. I will start serious work once I have more time. On a long term basis, I plan to build a small home and settle down in the farm. 

This sounds like a really solid plan, in that it addresses the concern of water right away. Rainfall in most of India can be quite variable from year to year. It might be over 600 mm one year and as low as 250 mm on a bad year. Sira also has a dry period of around 5 months each year.

 Are there any special considerations (Shape of land, amount of gradient, groundwater level, Soil quality) which I need to keep in mind while selecting a suitable piece of land for permaculture?

If Sira were a little farther north, I would recommend a north-facing slope to offer more shade (and thus more protection against evaporation). Because it is at 13°N, it won’t make a huge difference. A north-facing slope is slightly better, but not by much.

You will want to avoid slopes that are too steep to work, and keep in mind that any slope more than 20° is dangerous for machinery to work, and you will want to use machinery for earthworks. Labour is cheap in India, but manpower is still more expensive than a backhoe. Safe the human labour for grooming the earthworks. Slopes of greater than 20° can be terraced, though the cost is much greater for terracing than for dams. The most cost-effective, and beneficial approach for steeper slopes is to plant trees on them. Look towards something dual-purpose like Sesbania sesban, which provides, shade, fixes nitrogen in the soil, and can be used as a pole lumber. You could alley crop with S. sesban, provided there is easy enough access to the land.

Sesbania sesbans
Sesbania sesban alley cropping

As for soil quality, the more fertile, the better, of course. The problem is, most of the soils will be rather nutrient-poor, lateritic soils. Looking at satellite images suggests that the soil is iron-rich, which would bode well for mango production.

To boost soil life, fertility, and thus water-retention, add powdered charcoal to the site (AKA bio-char or ag-char). This will greatly assist in building soils. Application of mulch on its own, or even compost on its own will not contribute much to long-term increases in soil fertility. The charcoal dust allows biological processes to take hold.

That said, you would do well to build a shaded cement trough that you put compost worms in to produce vermicompost. If the trough is 60 cm by 3 metres, you will be able to produce a fair amount of very high-quality compost. This would be something for the long term, not something you implement immediately.

For ground water levels, the higher the better, unless the water has a high salt content that would damage crops. It does not look like this is the case, however.

 I don’t want to dig a bore-well. Average rainfall in Sira area is around 600mm. Will Permaculture techniques allow me to store sufficient rainwater to achieve water security? I would need water for both irrigation, and for domestic use (once I settle down). 

You might or might not get away without a bore. The majority of the wells I saw in Anantapur District were dug with an excavator. The town of Talupula, however, drew its water from a bore hole that was something like 1000 feet deep.

What will help you for household use is to make sure you catch the water that falls on the roof of the house you will build. You would also be wise to divert greywater from your kitchen into a heavily-mulched garden. Wasting water should not be done, particularly in such a  dry place.

In terms of earthworks, ripping will not work in your situation. The nature of the soil is such that any ripping you do will be erased with the first rainfall. What will work are large swales, gabions, and rock wall dams (unless you have a lot of good quality clay on site). Dams are the most expensive option and require engineering. Gabions, however, are relatively cheap and can make a large difference when placed across a temporary seasonal stream.

Filed Under: Article Tagged With: Arid climate

India: The Talupula Site, Part III

‘Arid Climate’ Articles at Permaculture Reflections

July 27, 2009 by Douglas Barnes 1 Comment

At the invitation of the Green Tree Foundation, I visited the town of Talupula in the drought-stricken Anantapur District in Andhra Pradesh. Once a dry tropical region, biotic pressures have changed the region into an arid landscape. Because of this, the Green Tree Foundation had me come in to design and implement water harvesting systems suitable for their area in an effort to assist with their regreening activities.

Site outside Talupula, APHaving selected a site for our project, I mapped the boundaries of the site with a GPS unit, and assessed the site’s features and vegetation. Being ferrosols, the soil structure was generally pretty uniform from the surface down to as much as 8 metres deep. And being gravelly, it was not appropriate for dam construction. This meant we would stick to swales for this site. The cost of digging the swales was well within the total allotted budget for the project, so we next looked into choosing the best machine for the job.

While digging out swales with a bulldozer with a tilting blade can be a convenient way of making them, the soils were so hard that they would have created a near impossible situation for the dozer to handle. Add to that the fact that the nearest dozer would be 6 to 8 hours away, requiring a transport fee, and that they would only come out for more than 100 hours work, bulldozers were not an option anyway. We were left with the choice of a backhoe or a small excavator. The excavator had speed going for it, but availability was a problem (we would have access to it only one day a week). It also required transport to the site (increasing its cost) and was 35% more expensive than the backhoe. The backhoe looked to be the best choice by far.

Designing the water-harvesting system, I did not want the site to be plagued by undersized swales. For one thing, I wanted them to be able to hold a lot of water before excess would go over their spillways. Also, if they did not have gradual enough walls, they would be more prone to erosion. Over time, swales gradually fill in, too. With larger swales, they would be around longer.

Douglas Barnes enjoying a fresh mango

The designer enjoying a fresh mango under a tamarind tree that saved him from heat stroke many times. Photo by Gangi Setty of the Green Tree Foundation.

As I wanted the swales to be around 1 metre from the bottom of the trench to the top of the mound, I designed the trench to be about 4 metres across (a little smaller on two of the swales) and about 4 metres across on the mound. The site was nearly devoid of vegetation, so to be on the safe side, I assumed 55% runoff, meaning a coefficient of runoff of 0.55. To determine the spacing of the swales, I used the formula

Spacing = Holding capacity per m ÷ (Runoff coefficient X Maximum rainfall in one event)

[Please note that this formula is flawed. We have a swale spacing calculator on the site to make your calculations for you.]

The volume of the swales per metre was to be around 1.7 cubic metres. The maximum rain in one large event in the area is 10 cm. From this, I calculated the approximate spacing for the spaces at 30 metres. Using the GPS, I was able to find the level for the second swale, 30m down from the top, then the 3rd level, 30 m down from there.

Map of swales on Talupula siteWe needed to map out the contour sites, so we tracked down some local engineers with a dumpy level. It turns out that the engineers owed a friend of the landowner a favour, so they came out to the site for free and mapped out the contour points for 4 swales on 3 different contours. While I planned on mapping the site myself, their proficiency had them finishing the mapping in half the time it would have taken me. They put us ahead of schedule by one day.

Image of surveying Talupula site

The map of the site showing the swales in red and the level-sill spillways in yellow.

Backhoe excavating swaleThe swales were excavated without too much incident with the total excavation taking about 3 and a half days to move 600 cubic metres of earth. We didn’t have the backhoe do everything. We simply had it dig trenches 3 metres wide and 50 cm deep, placing the excavated earth on the downhill side of the trench. The rest we were leaving to be groomed by hand. At one point, we hit rock that would have taken hours for the backhoe to chip through. In such cases, it is simplest to try to go around either uphill or downhill around the rock. We opted to go uphill. Apart from that one little snag, the rest of the excavation went as quickly as one could expect considering the soil was nearly as hard as concrete.

Labour team outside TalupulaWe hired a team of ten labourers to groom the site. Because the soils were so hard, however, we had the backhoe come back and chip off the uphill edge of the trenches it dug to make the process faster. The first day of grooming was gruelling work for the work team. They had to rely on picks to be able to chip through the earth to smooth out the edges of the swale. Grooming the mound was much easier as the soil there was already broken up. In the end, I had hoped to get the mounds groomed to a more gentle slope while the workers were there, but time ran out before we could get everything as perfect as the ideal I held in mind. Still, the edges are not steep and erosion should not be a problem.

On the night before the final day of work, the heavens opened up and released a torrent on the site. Excited to see the swales in action, the landowner rushed out in the middle of the night to see them fill up with water that would otherwise have washed down the hill in an erosive flood. When I arrived on site the last day, the top swale and one of the lower swales were full of water due to the slower infiltration from their slightly higher clay contents. Already they were a home to some very happy frogs that, with the rains, had come out of hibernation.

Swales filled with waterThe rains transformed the earth from a concrete-like surface to a soft and yielding one. This made the final grooming much, much easier. In order to help make the swales more durable, I had the work team put in compacted, level-sill spillways set at 90 cm from the bottom of the swales. With them in place, water can spill gently over the top in very heavy rains, greatly reducing the chance of erosion damaging the swales. The workers seemed to get a kick out of me inspecting the spillway with a site level and having them fix spots that were a few millimetres out. While it may seem fanatical, if the spillway is not dead-level, flowing water will concentrate in the lower spots. When it is concentrated, it moves faster, and when it moves faster, it has more erosive potential.

Swale spillway

Workers compacting the soil to create a level-sill spillway to allow overflow without eroding the swale.

Since the monsoon season hit just as the project was completed, it started collecting water right away. Within three weeks of the completion of the swales, they had already captured and saved over half a million litres of water. The land owner was initially worried about the amount of land that the swales took up – land that would otherwise have been dedicated to the mango tree crop that is to go in later. But upon seeing the results of the swales in action, he knew they were the right thing to do.

I was very fortunate to have the agroforestry expertise of the Green Tree Foundation to assist in the selection of tree species from the site. The plan was to plant a windbreak crop and living fence consisting of Gliricidia sepium, Caesalpinia crista and Sapindus trifoliate. G. sepium is a fast-growing nitrogen fixer with medicinal properties. C. crista makes a good windbreak and has anti-malarial properties. Sapindus trifoliate, as the name suggests, is rich in saponins, meaning it makes a great soap. Its fruit, which resembles a date, is a valuable crop that fetches a good price on the local market. I have received word from the Green Tree Foundation that these windbreak trees have already been planted on site and are doing well. When the mango crops go in, the Green Tree Foundation will provide nitrogen-fixing support trees to assist in the growth of the mango trees.

Given the swales and the addition of the trees, I suspect that within 3-years time, springs will appear at the bottom of the hill below the site. With the site’s exposure next to the national highway and the growing notoriety of the farmer we worked with, it is hoped that our project will be replicated by others throughout the area. I have been invited back by my friends at the Green Tree Foundation to do more work in the area, and I look forward to the day when funding permits me to go there again and carry out more projects.

Swale designer and work team in Talupua

The work team and the designer celebrate the project’s completion.

Filed Under: Article Tagged With: Arid climate, earthworks

India: The Talupula Site, Part II

‘Arid Climate’ Articles at Permaculture Reflections

July 11, 2009 by Douglas Barnes Leave a Comment

First impressions

This May, I visited the town of Talupula in the drought-stricken Anantapur District in Andhra Pradesh, India at the invitation of the Green Tree Foundation. Although I had seen photographs and general climate data for the region, I was struck but how dry Andhra Pradesh is. The province generally receives 350 to 700 mm of rainfall a year, and though I would like to report more specific rainfall for the District where the project was carried out, repeated requests to the government meteorological office by the Green Tree Foundation over the years have gone ignored.

When I first arrived, I met an engineer from Talupula who is living and working in Hyderabad. I went over what I was planning to do in terms of earthworks, which included swales and possibly a dam. When I mentioned that swales can be built with the aid of a bulldozer with a tilting blade or a grater with a tilting blade, he said that the soils were very hard and would require an excavator.

Lateritic soilUpon arriving in Talupula, I found the lateritic soils to be slightly more yielding than asphalt. The soils are ferralsols, which are an iron-rich lateritic soil that becomes hard after the land is stripped then subjected to repeated wetting and drying – just the conditions that occur in the dry tropics. When wet, they are very workable and may even bog down machinery working on it. When dry, they are are hard as pavement. In these soils, calcium, magnesium, potassium and sodium are weathered out, and there is next to no humus content in the soil. As a result, the cation exchange capacity is low, meaning that plant health suffers. While these soils do tend to lose potassium easily (another argument against the common practice there of burning pasture land as a management strategy), they do hold onto phosphorus well. They also respond well to amendments of lime and gypsum, though this was beyond the scope of our project.

Government irrigation projectThe Indian government is in the process of building a large irrigation channel to divert the flow of the nearest major river to the drier regions of the south. While I am personally skeptical of the ecological viability of this project, visiting the excavation site for the channel did give me the opportunity to examine the typical soil strata of the area. Lateritic soils are deep – sometimes running down to 20 metres in depth. I could see from the channel excavation that the gravelly soil continued down at least 8 metres to the bottom of the channel. All that gravel meant that I would not be designing and constructing an earthen dam as the gravelly conditions require considerable engineering for dam construction. The focus then became on swales and possibly gabions.

Obula Swami

Obula Swami, Talupula, APBefore I left Canada, a site in Talupula on public land on a small mountain outside of town was suggested. It is said that the deity Obula Swami lives at the summit of that hill. Our potential site there was the highest practical site to work on. On firsthand inspection, however, I found that the access to the site was difficult and there was very limited space to work in. There also were a number of rock walls already build on the site to combat erosion. And as it was public land, would it be subject to neglect, or destruction? A further problem was that shepherds regularly burn the land there, so establishing trees would be difficult at best.

We looked at a second site at the foot of the same mountain on private land. There was a good catchment and plenty of room to work on. After contacting the farmer, though, the restrictions he set made working there not worthwhile.

Gangahadr

For a few days, we were stuck without a site to work on. Then we got the approval of an organic farmer outside of town to do whatever we liked on a 7-acre hillside patch of his land. The farmer, Gangahadr, had already greatly benefited from the agroforestry advice of the Green Tree Foundation and was eager to see what we could do. The land was not too steep, and the nick point on the land (the point at which the hillside goes from convex to concave) was high enough that we could get up near the top of the hill and put in a series of swales. Being private, the land would be well cared for and access to it controlled. Gangahadr had a growing reputation in the area for excellent results, and the site was visible from the national highway, giving the project more exposure. As an added bonus, the site was adjacent to and would thus compliment a rock check dam built in 2005 by the Rural Development Trust. The effect of that dam has been to change the land downstream from desert-like conditions to a rich oasis. This was the site. I met with the Ganghadr and got his permission to build swales on his land.

In Part III, we will look at site planning, implementation, and the results so far.

Filed Under: Article Tagged With: Arid climate, earthworks

Neem

‘Arid Climate’ Articles at Permaculture Reflections

June 22, 2009 by Douglas Barnes 2 Comments

Azadirachta indica, neem, the village dispensary. This amazing tree has so many uses that it’s hard to imagine a tropical garden being complete without it.

First, the tree has a deep tap root, making it drought hardly. It is not, however, tolerant of seasonal flooding or of frost. It helps rejuvenate damaged soils. In the hot climates it grows in, its shade is very welcome. It also makes a good windbreak. Timber from neem trees is termite resistant – a good feature in the tropics – and its calorie-rich wood makes good fuel. The flowers of neem also make good bee fodder.

Neem leaves are sometimes used in curries and chutneys in India. Extended consumption over long periods has the potential to damage the liver, so consumption should be occasional. Also, neem should NOT be consumed by pregnant women, women trying to conceive, or by small children.

The dried leaves are used as a moth repellent to protect clothes, in grain and dried fruit stores to protect from insects, and as a general insect repellent. Fresh leaves are sometimes eaten to rid the body of parasites. Twigs from the tree are chewed on one end, then used as a tooth brush.

Azadirachtin, the active ingredient in neem, is a very effective pesticide. It repels insects and disrupts their growth and reproduction. A neem solution can be sprayed directly on plants to deal with existing insects and to help repel further insect attack. To make a solution, simply bring a bucket of water to boil, add 2 handfuls of crushed seeds or 6 handfuls of minced leaves, and steep for 1 hour. Add a small amount of soap as a surfactant, strain and spray directly on plants. If only neem oil is available, mix 10 ml of neem oil with 1% azadirachtin content (get certified aflatoxin-free neem oil) with 500 ml of water and a touch of soap and spray the mixture on plants. Neem can also be used on animals to kill fleas, ticks, intestinal parasites, and repel blowflies. For a topical solution for animals, mix 1 ml of neem oil to 30 ml of water and spray it on the animal’s coat.

Looking at the medicinal uses of neem, it is easy to see why it is called the village dispensary. It is an emollient (soothes the skin), a purgative (a laxative), a vermifuge (rids internal and external parasites), a digestive agent, an anti-inflammatory, a sedative, a carminative (prevents gas), an anti-fungal agent, an antiviral, an antiseptic, and a diuretic. The list of ailments it is used to treat includes but is not limited to:

  • Gastritis
  • Fever
  • Poor circulation
  • Bronchitis
  • Candida (yeast infection)
  • Gingivitis
  • Kidney problems
  • Duodenal and peptic ulcers
  • Liver problems
  • Diabetes
  • High blood pressure
  • High cholesterol
  • Hemorrhoids
  • Conjunctivitis (pink eye)
  • Tuberculosis
  • AIDS
  • Asthma
  • Rheumatism
  • Venereal disease
  • Skin ulcers
  • Urinary tract infections
  • Athlete’s foot
  • Ringworm
  • Head lice
  • Scabies

Neem, Azadirachta indica

Neem also has commercial value with popular products made from neem including soap, toothpaste, shampoo, candles, mouthwash, tea, and on and on.

If you are in the dry tropics and are looking for useful trees for your site, be sure to include this amazing tree to you list. With so many uses from neem, you’ll be glad you have it nearby, and your pests will hate you for it.

Filed Under: Article Tagged With: Arid climate, trees

India: The Talupula Site, Part I

‘Arid Climate’ Articles at Permaculture Reflections

June 20, 2009 by Douglas Barnes Leave a Comment

During the month of May, I was in the semi-arid region of Andhra Pradesh, India at the invitation of the Green Tree Foundation. The spread of desertification is something that I have written about here in the past, but to see the environmental degradation of a region that had formerly been a dry-tropical region of forest and savannah is always a real jolt. If nothing is done to halt the biotic pressures of deforestation and uncontrolled grazing and to repair the damage that has been done, this region will become a desert in the not too distant future.

Some forest is lost by people cutting trees for fuel wood but, as many species in the tropics coppice vigorously and firewood cutting tends to coppice the trees cut, this is not the major cause of deforestation there. The major causes of deforestation are land clearing for agriculture and land destroyed by grazing animals or by shepherds setting fire to the land as a management strategy. Also, grazing is communal by default. If land can be accessed by shepherds, both private and public land will be grazed.

The quickest means of repairing the land might arguably be by the controlled grazing techniques of Holistic Management®. This method would involve using one of the current degraders of the environment – grazing animals – to regenerate the land. I gave the practicalities of this approach some thought. To do just one District of the province would involve a large scale educational program to teach Holistic Management® to thousands and thousands of shepherds. It would also require each shepherd to have portable electric fencing to contain their herds in a controlled area for a controlled amount of time. Additionally, a sophisticated database, easily accessible by cell phone (the only communication tool at a shepherd’s disposal) would be needed to track grazed land and grazing schedules of different plots of land. The alternative, if Holistic Management® were to be employed, would be to have land owners fence their land into small plots and control animal access themselves. One problem here would be to convince the land owner that there would be benefit to him were he to shoulder the expense of fencing and managing the grazing on the land. The alternative is to only allow grazing on one’s own land. The problem here being that this approach would ruin the livelihoods of thousands of families, throwing them into poverty.

Were a land owner looking to raise animals on his or her own land, Holistic Management® would be the ideal approach to take. But as a large-scale solution to the problems of the region, it strikes me as being not very practical given the current system of de facto communal grazing. It would require massive coordinated effort, billions of rupees in training and billions in material costs to make it a reality. And then, it relies on everyone following the rules. While not impossible, it would be extremely difficult to carry out this approach successfully, I think.

The approach that my associates at the Green Tree Foundation are taking is a tree-based approach. The problems are well defined: poverty from a degraded environment; the environment degraded by biotic pressures – mostly from grazing animals. The solution they are using is to try to replace the forests that once stood and to shift agriculture in the region to an agroforestry-based system.

They are surveying local villages, finding the material needs of the villagers, selecting appropriate tree species based on local conditions and local needs, and supplying trees at low or no cost to the farmers and citizens of the village. To address the problem of grazing animals specifically, they often seek out productive tree species that are non-browsable or use non-browsable species as a living fence to exclude grazing animals from a site. They are planting agave as a firebreak to protect their planted areas from the fires set by shepherds. They are also encouraging the use of fodder trees for animal feed. Penned animals cause no damage to surrounding lands and feed can be cut and carried from fodder trees to the animals.

The main goal of my visit was to establish water harvesting earthworks and to demonstrate to the Green Tree Foundation staff the proper design and implementation of those earthworks. In Part II, we’ll look at site selection for our water-harvesting project there.

Filed Under: Article Tagged With: Arid climate, earthworks

Euphorbia tirucalli

‘Arid Climate’ Articles at Permaculture Reflections

January 17, 2009 by Douglas Barnes Leave a Comment

Other names that E. tirucalli has gone by include Arthrothamnus tirucalli, Euphorbia media var. Bagshawei, Euphorbia scoparia, Euphorbia media, Euphorbia rhipsaloides, and Euphorbia rhipsalioides.

Euphorbia tirucalli is an African tree that grows in semi-arid, savannah conditions. It is very drought resistant, withstanding long dry seasons. It is salt tolerant and can withstand to just under 5000 ppm arsenic. It will grow from 4 to 15 m tall and at altitudes to 2000 m elevation in hot savannah climates.

It is a coppiceable tree. When coppicing it, cut it at 20 to 30 cm from the ground. It makes good fuel wood with 17,600 kilojoules per kilogram of dry wood; and through pyrolysis, it makes not only charcoal, but also a high octane gasoline substitute. (One to two tonnes of fuel per hectare is what you can expect.) It can also be used as a diesel source.

The timber is useful. And it can be used as a living fence as it is not grazed by animals. Caution must be applied when planting this tree near any human settlement. It must not be in a location where it can contaminate wells or water collection sites as the tree contains co-carcinogens. Latex from the tree can be used as an insecticide and as a fish poison. As an insecticide, it is effective against Colletotrichum capsici, Fusarium pallidoroseum, Botryodiplodia theobromae, Alternaria alternata, Penicillium citrinum, Phomopsis caricae-papayae and Aspergillus niger and against the nematodes Hoplolaimus indicus, Helicotylenchus indicus and Tylenchus filiformis. The latex can also be used as a glue.

It has medicinal properties, though one would use caution obviously. The young twigs from the tree are roasted (presumably breaking down the poisons) and chewed to sooth sore throats. A poultice made from the greenwood is used to treat broken bones. Despite the toxins and co-carcinogens it contains, some of its compounds have been used to treat cancers.

Filed Under: Article Tagged With: Arid climate, trees

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