There is a first time for everything, as the saying goes. And for CIAT´s Soils Research Area, the project “Confronting the challenges of smallholder farming communities: Restoration of degraded agroecosystems,” provided the entry point for a new effort in Paraguay to enhance the livelihoods of smallholder producers through restoration of soils and landscapes that are degraded, and conservation of those that are still in good health.
With assistance from the German Agency for International Cooperation (GIZ, its German acronym) and financial support from Germany´s Federal Ministry of Cooperation and Economic Development (BMZ), the project is focusing on two regions of strategic importance.
One is the buffer zone of the Mbaracayú Biosphere Reserve, which is a major remnant of the Atlantic Forest in Paraguay. CIAT scientists are working in this area with the Moisés Bertoni Foundation to help smallholders improve their systems for producing yerba mate (used to make a traditional beverage) in the shade of native tree species. The idea is to establish green corridors in the landscape, which has been extensively deforested, with severe soil degradation resulting from large-scale production of soybean and other crops.
Cover crops are being rediscovered at the forefront of new agriculture.
Don’t Farm Naked
Cover crops such as rye, alfalfa, and clovers are needed to protect soil from excessive rain and sun, provide organic structure, distribute nutrients, and limit harmful pests and weeds. They also provide economic benefits through reduced fertilizer needs, fewer problems with pests and weeds, and often, larger yields.
Cover crops are classified into legumes and non-legumes with each grouping having its particular applications and benefits.
Legumes like alfalfa, clovers, cowpeas, medics, soybeans, sunn hemp, velvet bean, and woolypod vetch are part of the pea family. Often referred to as green manure, leguminous cover crops can be tilled under and incorporated into the soil where their decomposition provides nitrogen, phosphorus, and other nutrients to subsequent crops. Legumes also help prevent erosion, add organic matter to soil, and attract beneficial microorganisms and insects.
Cereal grains, grasses, brassicas, and mustards make up the non-legume category.
The high carbon content of grasses and grains like barley, oats, rye, sorghum-sudangrass, wheat, spelt, and triticale leads to a slower breakdown of their organic materials. This biomass lasts longer and is effective at limiting weeds, especially when left on ground as mulch. Their low nitrogen content relative to legumes also makes them effective nitrogen scavengers, important for balancing soil that has become oversaturated with nitrogen. This leads to a higher all around nutrient extraction with less nutrients left over for the next crop. Buckwheat is particularly effective at drawing out phosphorus and calcium from the soil. Like legumes and most cover crops, grasses and cereals also help limit soil erosion.
Brassicas and mustards like arugula, kale, rapeseed, and turnips, while not legumes, are in between legumes and grasses regarding nitrogen content and rate of breakdown. They are effective pest controllers due to strong chemical compounds released during their decomposition process that are toxic to pests and weeds, while reducing the prevalence of disease in subsequent crops. Brassicas and mustards tolerate cold and drought well, have expansive roots, and serve as useful feed for grazing animals.
Following on traditional farming practices around the world, the Land Institute focuses on crops which are perennial, meaning they live all year, and are harvested multiple times, instead of just once before dying. The Land Institute believes in agriculture in harmony with nature. The complexity that perennials and cover crops bring to soil supports biodiversity and improves soil health. “This web of checks and balances, predator and prey that make up complex ecosystems make it difficult for any single species to dominate. Instead, a self-regulating equilibrium sets in.”
I have been reading up on your blogs on sand dams. Very very interesting and very much in need in Southern Africa as well. I am looking to make a difference in South Africa and I hope that you will be able to assist me in the execution of my dream and vision of a better future for all in this beautiful country.
I am hoping that you will be able to guide me in the right direction. We are setting up projects to create jobs in small rural towns in the more arid areas of Southern Africa. We are looking at small towns with 80% unemployment rate and higher. The idea is to put together a workable and sustainable plan to create jobs and also address issues like alcohol and substance abuse. Big problems with foetal alcohol syndrome and we want to do our best to obliterate that.
I sat down and started putting small projects together to create work for women in particular. Bee keepers, handwork, leather shoes with African beading, wool products, mohair products, living gardens in handmade concrete boxes, etc.
Our main object though is to create sustainable income with harvesting a local declared weed for animal feed. What I would like to know: is it possible to change the climate in arid areas by planting drought resistant plants that can be used for food, fuel and animal feed. Will the plants be able to make a positive impact on the ground and the climate. I am looking at using plants to try and turnaround areas previously marked as desert and semi-desert areas back to useable fertile land that can be used for food crops.
I will really appreciate your input if possible.
RTM Project Support Administrator
British American Tobacco South Africa
My reply (Willem Van Cotthem)
Thanks for your message and congratulations for your efforts.
I will first try to answer your questions:
(1) Is it possible to change the climate in arid areas by planting drought resistant plants that can be used for food, fuel and animal feed?
In order to change the local climate in a significant way, one needs to cover up a desertlike environment with trees and shrubs. These will transpire a lot of water in the air and give sufficient shadow over the soil to limit evaporation of the soil moisture. Gradually the area will become less arid.
I see one immediate solution for South Africa, that is to start planting cuttings of the Elephant bush (spekboom,Portulacaria afra), a drought tolerant species that is widespread in the country and is favourite fodder for animals (elephants, antelopes, goats, sheep, etc.). It has a remarkable characteristic: little leaves falling on the soil start rooting with some moisture and give new plants, forming a real bush.
I would start with spekboom cuttings in a nursery and multiply constantly to be able to cover a large area.
One can also use a drought tolerant bamboo:
Oxytenanthera abyssinica, the savannah bamboo (see Google). It is a very hardy bamboo and can grow on poor soils. This fast growing species can also be grown from cuttings and rhizomes. People use it to make various types of local baskets for transporting produce, but the main use is as building material (scaffolding, house construction, fencing, even furniture). It could be used for soil erosion control and rehabilitation of degraded areas.
(2) Will the plants be able to make a positive impact on the ground and the climate? I am looking at using plants to try and turnaround areas previously marked as desert and semi-desert areas back to useable fertile land that can be used for food crops.
Growing plants always have a positive impact on the soil. As for the climate, it depends upon the density of the vegetation cover (one needs bushes or even a wood with trees).
Aiming at turning a desertlike area into fertile land is a rather difficult exercise. One of the well-known methods is densely seeding the land with leguminous species. Please read this article:
You will find a lot of interesting ideas, e.g. the use of cowpea (Vigna unguiculata), gum arabic tree (Acacia senegal), honeybush (Cyclopia), rooibos tea (Aspalathus linearis), groundnut (Arachis hypogea), etc.
Once (and not before) the effect of these leguminous species is significant, one can start to use the land for food crops.
However, I would like to recommend the set up of plantations of the spineless cactus Opuntia ficus-indica var. inermis (which means without spines). Please Google “nopales” to find sufficient information on the huge plantations in Central and South America, where billions of people are eating these cactus pads and fruits.
(3) My attention was taken to your project : “living gardens in handmade concrete boxes”.
This is extremely interesting, because it coincides with my continuous efforts to convince people to switch from classic gardening (food production in a kitchen garden) to “CONTAINER GARDENING”.
As you know, the main problem for gardeners is the quality of the soil (drought, lack of organic matter, pests, etc.).
Well, by growing vegetables and herbs in all sorts of containers (pots, buckets, bottles, plastic bags, sacks, barrels, etc.) one can avoid most of these gardening problems. Let me recommend to have a good look at my websites and Facebook pages concerning container gardening and you will discover numerous simple, cheap and efficient ideas for food production in arid, semi-arid and sub-humid regions.
MY WEBSITES AND FACEBOOK PAGES (Willem Van Cotthem)
“Before we used to get some good rains that enabled us to get enough food but in the recent years it has been gradually decreasing and we are now not able to get enough food, even though we put efforts in farming.”
Joseph Kilonzo, Mumbuka self-help group, southeast Kenya
Migration and conflict over sparse resources are already on the rise, and if current trends continue, hunger and poverty are likely to become more widespread.
Every country in the world uses its land for food and water. For those of us who are lucky enough to enjoy abundant water from a tap and buy any food we want from a supermarket, it’s not something we have to consider very often.
But the reality is that fertile land and sustainable water sources are diminishing at a frightening rate. In fact, desertification of land poses one of the greatest challenges of our times. 12 million hectares of land (greater than the size of Portugal) is lost to desertification every year. This equates to an area where 20 million tons of grain could have been grown.
Until recently, smallholder farmers in the world’s poorest and driest regions were bearing the most immediate effects of desertification, but the loss of arable land is quickly becoming a global problem.
California in the United States, for example, declared a state of emergency earlier this year due to its fourth consecutive year of severe drought. Usage of water for households, business and farmers has been severely restricted, having a real impact on people’s incomes and day-to-day lives. As a result, farmers in California are planting less crops, reducing food production, which in turn is having a negative impact on food prices.
If current trends continue, it is thought that land degradation over the next 25 years could reduce global food production by up to 12 per cent, resulting in a 30 per cent increase in world food prices. Migration and conflict over sparse resources are already on the rise, and hunger and poverty are likely to become more widespread, reversing hard-won development goals.
by the German Federal Ministry for Economic Cooperation and Development (BMZ) – Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)
The sector project Land degradation, especially in arid regions (desertification), is a growing challenge for development policy in all parts of the world. The Convention to Combat Desertification (UNCCD) was adopted by the United Nations in Rio in 1992. Germany has been an active supporter of the Convention from the start and hosts its secretariat. The Sector Project to Combat Desertification assists the Federal Ministry for Economic Cooperation and Development (BMZ), Germany‘s UNCCD focal point, in developing policies and strategies relating to all aspects of land degradation and desertification. The Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH has been commissioned to implement this sector project.
What challenges do we face?
In light of the constantly growing world population, food production needs to increase by 50-70 per cent by 2050 to ensure food security. Yet soil loss and land degradation are advancing – a quarter of the world’s land surface has become degraded in the past 25 years and each year a further 20 million hectares are affected. Therefore, in order to achieve long-term development goals it is essential to increase yields and at the same time to conserve land and soils, which form the basis of agricultural production. The causes of land degradation must be tackled and political conditions must be improved to provide greater incentives for sustainable land management. Promising existing schemes must be boosted and extended.
The Living Soils Save Lives program trains farmers to value and cultivate life in the soil in order to offset the negative environmental and social impacts of modern agriculture. (The Hummingbird Project)
Soil Building in India’s ‘Suicide Belt’
The tragic phenomenon of farmer suicides in India is symptomatic of the damage that unchecked agricultural development has wrought, according to Delhi-based environmentalist Dr. Vandana Shiva. As explained in Shiva’s The Violence of the Green Revolution, technologies of modern agriculture, such as synthetic fertilizers, pesticides, and mechanized tillage, have destroyed the biodiverse ecosystems that, in the past, guaranteed the security of a farmer’s livelihood.
Marilyn McHugh and Chris Kennedy, agricultural advocates and Shiva’s social-work collaborators, share her view: the husband-and-wife team considers the growing incidence of farmer suicides in India as the complex outcome of the unsustainable methods of modern agriculture. McHugh and Kennedy argue that there are strong connections between the soil’s compromised ability to function in modern farming systems and the larger issues plaguing Indian farmers. Accordingly, the health of the soil is a major factor in addressing the issues that lead farmers to commit suicide.
After seeing the devastated soils—and communities—in rural India’s “suicide belt” in 2010, McHugh and Kennedy created a nonprofit soil-restoration organization, The Hummingbird Project, and soon after founded the Living Soils Save Lives project. “We call the program ‘Living Soils Save Lives’ because living soils provide an alternative to the unsustainable cycle of debt and loans to purchase fertilizers, seeds and pesticides that has led to such dire outcomes for so many farmers,” explained Kennedy.
Poor Soils A Huge Limitation for Africa’s Food Security
EXPECTATIONS HIGH FROM GLOBAL SOIL WEEK AND INTERNATIONAL YEAR OF SOILS
TEXCOCO, MEXICO, April 19, 2015 – Sustainable Development Goals being addressed at the Global Soil Week cannot ignore dependence on maize as a staple food for millions in Africa, and the need to help smallholder farmers maximize yields in African soils.
Today, Berlin, Germany, hosts soil scientists from across the world who have converged for the Global Soil Week (GSW) to find solutions for sustainable land governance and soil management. Farmers and other stakeholders in agriculture are keen to see outcomes that will translate into healthier soils for sustainable development in Africa and elsewhere.
For Africa’s smallholder farmers, low-fertility soils with poor nitrogen-supplying capacity are only second to drought as a limiting factor. Consequently, farmers suffer low yields and crop failure, a situation that has crippled food security for more than half (60 percent) of the population in this region who depend on smallscale farm produce.
To improve productivity, farmers apply nitrogen fertilizers, which provide necessary nutrients the soil needs to feed plants. However, most farmers cannot afford to apply the required amount of fertilizers because the costs are too high for them. It is estimated that nitrogen fertilizer costs as much as six times more in Africa that in any other part of the world. “For my one-acre farm, I use a 50-kilogram bag that costs KES 4,000 [USD 42]. This is a lot of money, so I have to use very little to save for the next planting season,” says Ms. Lucy Wawera, a farmer in Embu County, Kenya.
There are a lot of big facts about soil knocking around this year – on account of it being the International Year of Soils.These are great for mobilising much-needed global interest and action in efforts to protect this finite resource on which our lives depend (even the White House posted a blog on ‘Why soil rocks’ last week).
But it is small scale farmers who suffer the effects of land degradation and poor soil health the most – and, as guardians of 80 per cent of the world’s farmland, it is they who are most in need of affordable and practical solutions to protect their soil.
Research plays an important role in this – analysing the effects of climate change on soil or the causes of degradation and erosion, and testing different options to determine best-bet solutions for farmer circumstances.
But how do research results get into farmer’s hands?
In East Africa, scientists are turning to television…
The arid southern highlands of the Bolivian Andes are a harsh environment for even the most hardened farmers. The ‘quinoa boom’ and the move to mechanisation have led to shortened fallows and a drastic drop in soil organic matter. The dry sandy soils and the natural vegetation they support are increasingly degraded, but in the face of climate change and higher risks of drought, frosts and hailstorms, technical recommendations pay little attention to soil health. Farmers in the community of Lloco, however, have preserved their traditional practices that care for their fragile sandy soils and maintain resilience.
Fallow, manure and mulch
After a ‘typical’ 20 to 30 year fallow, site preparation begins 3-12 months before the rainy season. The tallest shrubs are cut, leaving cut material on the ground as mulch and leaving the smaller shrubs and herbs alone. Manure is moved from grazing areas and piled where the shrubs were cut and covered with straw to reduce nutrient loss from strong winds that are common. Most families in Lloco collect manure from their own llama herds, otherwise they have to exchange or buy it from families with larger grazing areas.
In the middle of the short rains which usually last only two months (January and February), manure is spread evenly over the fields and hoed in, before the soil is covered with straw from a common unpalatable local grass called sikuya. The straw protects against erosion, against the sun, and reduces the soil from drying out during the cold and dry months. Timing of this activity is crucial, to maximise soil moisture and nutrients, in preparation for planting six months later. Crops are sown in advance of the rainy season, so that there is enough time to complete a growing cycle before the onset of winter. Potatoes are planted for two to three consecutive years before being followed by quinoa and barley. The typical rotation may be described as potato-potato-potato-barley, potato-potatoquinoa-barley or potato-quinoa, depending on the soil fertility and soil humidity.
More than two decades ago in the Irrawaddy delta in Myanmar, farmers began planting two rice crops each year. Rice production increased, but for how long? Depleted organic matter and acidification are now affecting soil health, and farmers who can’t afford fertilizer are seeing their rice yields declining. This is why 200 farmers started to compost rice straw. With this they have been able to maintain rice yields and reduce fertilizer costs. They are still improving their composting techniques and some are starting to experiment with green manures.
Compost made easy
In 8-12 weeks, the straw from a hectare of paddy can produce 2.5 tonnes of good quality compost, which when added to the soil provides 50 kg of nitrogen, or 40-50% of the total nitrogen requirements of a rice crop. Cutting fertilizer costs by half is a huge advantage for farmers as they struggle with debt from the need to buy more and more fertilizer each year.
The basic compost combination is dry matter, fresh green matter and a microbial input. Rice straw, dried leaves and even coconut fibre are good sources of dry matter. Freshly cut leaves and weeds, banana trunks, water hyacinth, or any plants in and around the fields and gardens are used as green matter. The microbial input helps to transform the biomass into the nutrient-rich material we call compost, whether it is fresh soil, forest humus, animal manure or fresh compost. Handfuls of wood ash add phosphorus and potassium and even the basic combination can be adapted. If a farmer has no more green matter, he will still get compost but of a different quality. And if manure is in short supply, it helps to add a diluted solution of cow or pig dung with rice straw and other dry matter. This promotes the growth of microbes, nitrogen content and decomposition, and is a cheap and easy way to overcome the lack of green matter or manure.
How can we take advantage of halophyte properties to cope with heavy metal toxicity in salt-affected areas?
A halophyte is a plant that grows in waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs, and seashores. (Wikipedia)
Background Many areas throughout the world are simultaneously contaminated by high concentrations of soluble salts and by high concentrations of heavy metals that constitute a serious threat to human health. The use of plants to extract or stabilize pollutants is an interesting alternative to classical expensive decontamination procedures. However, suitable plant species still need to be identified for reclamation of substrates presenting a high electrical conductivity.
Scope Halophytic plant species are able to cope with several abiotic constraints occurring simultaneously in their natural environment. This review considers their putative interest for remediation of polluted soil in relation to their ability to sequester absorbed toxic ions in trichomes or vacuoles, to perform efficient osmotic adjustment and to limit the deleterious impact of oxidative stress. These physiological adaptations are considered in relation to the impact of salt on heavy metal bioavailabilty in two types of ecosystem: (1) salt marshes and mangroves, and (2) mine tailings in semi-arid areas.
Conclusions Numerous halophytes exhibit a high level of heavy metal accumulation and external NaCl may directly influence heavy metal speciation and absorption rate. Maintenance of biomass production and plant water status makes some halophytes promising candidates for further management of heavy-metal-polluted areas in both saline and non-saline environments.
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