I’m an enthusiastic follower of various blogs relating to rural development, in particular Nourishing the Planet and Practical Action. The former referred me to a recent publication which I have been perusing with interest ‘Innovations in Action: Nourishing People and the Planet.’ I particularly enjoyed reading this report as much of the focus was on very practical ways (including highlighting the work of Practical Action) of improving the lives of people in the developing world, from the use of better food storage vessels which preserved fruit and vegetables for longer to better irrigation systems. A number of these innovations relate to soil and water and are summarised below, but I strongly recommend reading the whole report.
Keeping It Cool. . . and Hot
An Israeli company has developed a system that could help farmers beat the heat. Root Zone Temperature (RZT) Optimization technology uses geothermal energy to enable farmers to control the soil temperature at root zones, increasing plant growth and production dramatically. A low-pressure pump, powered by a solar panel, circulates water beneath the soil surface, cooling the ground in the summer and warming it in the winter.
By maintaining plant roots at an optimal 22–30 degrees Celsius, this system boosts plant growth and has increased yields of strawberries, cucumbers and peppers as well as helping crops mature earlier.
Improving the Harvest, from the Soil to the Market
Farmers in Tanzania are fighting a losing battle against increasingly degraded land. Repeated plantings quickly deplete soil nutrients, leaving it barren and vulnerable to erosion. Downstream, the water is dark with sediment, unfit for drinking, and expensive to treat. A CARE International initiative encourages smallholder farmers to use techniques that help restore—and hold in place—the soil.
Farmers and smallholders are building terraces to limit soil runoff and erosion and planting trees as crops on otherwise unused areas of their land. This helps sequester carbon in the soil and restores much-needed nutrients. Farmers are also encouraged to leave sections of their land fallow for one- or two-year periods to give the soil a chance to regenerate on its own.
Putting a Stop to the Spreading Sands
Throughout the Sahel, recurrent drought since the late 1960s is turning formerly crop-covered land into desert. Sand dunes are covering villages, roads, crops, and irrigation systems, making it increasingly difficult to farm and maintain infrastructure. To tackle this, fences are being erected to redirect the wind in order to create artificial dunes. These dunes reduce the strength of the wind and slow the advance of more sand.
The fences are constructed from branches and twigs collected from mature forests and woven together, the materials provide just enough permeability to slow the wind speed while still remaining upright in the face of strong gusts. Long-term barriers are then created by the planting of dry-tolerant and indigenous tree species to act as barriers. As well as restricting the spread of the sand, the natural walls also provide new source of food, firewood, seed, and livestock fodder.
Water from Thin Air
In parts of sub-Saharan Africa, people are forced to travel long distances and to spend hours at a time collecting water from far-away streams or wells. But the residents of Cabazane simply use gravity to let water come to them. At an altitude of 1,600 metres, steel cables held by wood posts support two layers of shade-cloth nets used to catch tiny droplets of water from passing mountain fog.
The droplets create runoff that is captured in gutters beneath the nets and the water is carried by tubes down the mountainside and to the village. Each square metre of netting provides up to five litres of water daily, and most importantly, the water from the clouds is very clean—a particularly valuable commodity in an area that previously suffered from water shortages. The nearest stream to the village, two kilometres away, is contaminated by livestock and a source of disease.
For Pest Control, Follow Nature’s Lead
According to this report, the more varieties of vegetables, plants, and insects that are included in a garden, the less vulnerable any single crop becomes. Mans Lanting of ETC Foundation India wrote in 2007 that the best method of approaching pest control is to learn to live in harmony with pests instead of trying to fight them. By harnessing the natural state of vegetation and pests, a farmer can create “a system in which no component can easily dominate” and in which soil and crop quality is greatly improved.
Traditional farming leads to soil fertility decreasing when crops are harvested, and growing a single crop means that the soil is further stripped of nutrients with each season, requiring the use of inputs that, according to Lanting, lead to an imbalance in plant nutrition and increase vulnerability to pests and diseases. This introduces the need for pesticides, which cost more money and create toxic runoff that can damage the local environment.
Instead, Lanting recommends taking an alternative approach, mimicking the diversity that takes place in nature and creating a garden that relies on natural systems to provide nutrients as well as pest and disease control.
Ploughing and other soil-management practices have raised yields in monoculture systems over the last 60 years, but have also done considerable damage to the soil through nutrient loss and erosion. Zero tillage, on the other hand, helps retain soil moisture, prevent erosion, and conserve nutrients.
In Argentina the use of zero tillage in soybean cultivation has led to an estimated gain of US$4.7 billion since 1991, and created 20,000 farming and extension-related jobs between 1993 and 1999. In northeastern India, rice and wheat cultivation increased following the development of zero-tillage drills in the 1990s. Zero or reduced tilling is now used for one-fifth to one-quarter of wheat production and farmers there have been able to increase their incomes $97 per hectare because of improved production and the reduced cost and time for soil preparation. Farmers in Tanzania who used tools made specifically for zero-tillage agriculture saved 75% of the time usually spent on land clearing and field preparation.