Soils are indeed at the core of any crop production system. Without a healthy soil, crops cannot thrive. While measuring the effect of soil erosion at national and global scales is near impossible, all farmers see the difference when effective soil conservation techniques are in place.
Putting the right strategies in place to control erosion is becoming increasingly urgent as climate change is leading to rains falling more erratic and intense than before.
From the gentle rolling lands in Burkina Faso to the steep hills in northern Vietnam, I have seen the devastating effects of rainfall on poorly managed soils. On gentle slopes of even as small as five degrees, the torrential rains wash away the top soil and seal the top layer, after which no more water can penetrate the soil. To remedy this, farmers in Burkina Faso learned about making contour bunds (raised ridges every 20 meters across the field) to allow the rainwater to infiltrate. On steeper slopes, where the land is much more difficult to be ploughed by anaimals or machines, vegetation barriers or terraces are possible solutions to stop soils eroding.
Depending on the slope, type of soil, availability of labour and other resources a wide range of options are available to improve soil and water management. Networks such as WOCAT (the World Overview of Conservation Approaches and Technologies) support organisations working on the ground with farmers by making hundreds of sustainable soil and water management technologies available in an authoritative website.
While many development agencies and projects believe that encouraging smallholder farmers to use mineral fertilizers is the quickest way to solve low crop productivity, without proper soil conservation techniques farmers will see most of their money invested wash down the drain.
And many more under Sustainable Land Management
The WOCAT SLM database: https://qcat.wocat.net/en/wocat/
About 10% of greenhouse emissions are from agriculture, especially from wet rice cultivation. Rice plants need a lot of nitrogen which is often provided as urea, a chemical fertilizer which is usually broadcast by hand into the irrigation water: this is easy, but wasteful. Some 60% of the nitrogen fertilizer is lost as it is transformed into gases and enters the atmosphere. Some nitrogen is washed away by irrigation water. A practical alternative known as â€śurea deep placementâ€ť makes much better use of nitrogen.
Urea usually comes in round grains, the size of fine gravel. For deep placement, the small grains are pressed into larger, oval pellets, about the size of your thumbnail. The farmer pushes these â€śsuper granulesâ€ť of urea into the soft soil, between four rice plants. This deep placement puts the urea underground, near the plantsâ€™ roots, so less nitrogen escapes into the air and water. The rice crop yields more and the farmers save money because they only need to use half as much fertilizer.
The efficiency of urea deep placement was demonstrated by 1980. The practice has not been adopted more widely because of the lack of supply of the super granules, the additional labor required and the difficulty of correctly placing the super granules in the field. Â But by the early 2000s, urea deep placement re-emerged in parts of Asia. The manufacture of small briquetting machines meant that the super granules could be made at the village level, and has led to a dramatic increase in their use, e.g. in Bangladesh (Giller et al. 2004).
There are two types of innovations: some you can try alone and others need to be adopted by a network. A solitary person can plant a new crop variety, for example, but it takes many people to start using super granules. Â A manufacturer has to build the briquetting machines. A second manufacturer has to buy a briquetting machine, make the super granules and sell them. Extensionists have to teach farmers how to place the super granules in the rice field. Then the farmers have to use the super granules, and make the idea their own.
It is kind of a chicken and egg problem. Farmers can’t use the super granules until someone makes them. Nobody will make them if there are no customers.
A step in the right direction is to show farmers the value of the super granules. The IFDC (International Fertilizer Development Center) commissioned Agro-Insight to make a farmer learning video on how to use urea deep placement. The video was filmed in West Africa, but the concepts also apply to Asia or even Latin America.
Of the 80 million hectares of irrigated rice worldwide, two million are in Latin America and the Caribbean, where 800,000 smallholders make their livings growing rice: 59% of which is irrigated (i.e. appropriate for urea super granules). And the region has the most potential of any to expand irrigated rice production. Rice is a popular food; tropical Latin Americans eat an average of 37 kilos of milled rice every ear, equivalent to a generous portion of 1.3 cups of cooked rice per day. As incomes increase, Latin Americans eat (and import) more rice.
As Latin America and the Caribbean grow more rice, it will help to make better use of nitrogen. So the urea deep placement video was recently translated to Spanish (there was already a Portuguese version). The video is a start, as it can teach farmers and extensionists about the importance of using fertilizer more efficiently, so that farmers can start to demand super granules and encourage companies to make and stock them. Even without super granules, growers of any crop will harvest more and save money if they grasp the idea that urea goes further if it is buried in the soil. This innovation makes a small contribution towards solving the problem of global warming.
Bent, Elizabeth 2015 The ground exhales: reducing agricultureâ€™s greenhouse gas emissions http://theconversation.com/the-ground-exhales-reducing-agricultures-greenhouse-gas-emissions-40795
Giller, Ken E., Phil Chalk, Achim Dobermann, Larry Hammond, Patrick Heffer, Jagdish K. Ladha, Phibion Nyamudeza, Luc Maene, Henry Ssali, and John Freney 2004 â€śEmerging Technologies to Increase the Efficiency of Use of Fertilizer Nitrogen,” pp. 35-51. In Arvin R. Mosier, J. Keith syers and John r. Freney (Eds.) Agriculture and the Nitrogen Cycle: Assessing the Impacts of Fertilizer Use in Food Production and the Environment. Washington: Island Press.
Pulver, Eduard 2010 â€śManejo EstratĂ©gico y ProducciĂłn Competetiva del Arroz bajo Riego en AmĂ©rica Latina,â€ť pp. 350-362. In VĂctor Degiovanni B., CĂ©sar P. MartĂnez R., & Francisco Motta O. ProducciĂłn Eco-Eficiente del Arroz en AmĂ©rica Latina. Volume 1. Cali, Colombia: CIAT. http://ciat-library.ciat.cgiar.org/Articulos_Ciat/2010_Degiovanni-Produccion_eco-eficiente_del_arroz.pdf
Savant, N. K. and P. J. Stangel 1990 â€śDeep Placement of Urea Supergranules in Transplanted Rice: Principles and Practices.â€ť Nutrient Cycling in Agroecosystems 25(1):1-83
A good video, one that lets farmers tell about their innovations, can spark the viewersâ€™ imagination. A video can even convince smallholders to try a new crop.
Mpinda grows vegetables, and sells them in the market in Mwanza. In 2013, he was able to use his earnings to buy a small, gasoline-powered pump to water his beans, onions and tomatoes. A $100 pump is a major investment for a Malawian smallholder, but also a great way to save time and avoid the backbreaking labor of carrying water from the well to the plants during the long, hot dry season.
In June 2015, Ronald Kondwani Udedi left some DVDs with videos at a government telecentre managed by Mathews Kabira, near Mwanza, Malawi. The DVDs had learning videos for farmers about growing rice and chilli peppers and managing striga, the parasitic weed.
Mathews took one set of DVDs to Mpinda, because he was â€śa successful farmer. Mpinda had a DVD player, but no TV, so he watched the videos on chilli growing at a neighborâ€™s house, using the neighbors TV and Mpindaâ€™s DVD player. He watched the videos as often as the neighbor would let him. The more he watched, the more he learned.
Mpinda soon recognized the possibilities of chilli as a crop, even though he had never grown it.
To start a new crop you need more than a bright idea; you need seed. Getting chilli seed took some imagination. Mpinda went to the market and bought 20 small fresh chillies for 100 Kwacha (14 cents) and then dried them, like tomatoes, and planted the little seeds in a nursery, just like he had seen in the video. Mpinda had already been used to making seedbeds for onions and some of his other vegetables. At 21 days he transplanted the chilli seedlings, as he had seen on the videos.
Every few days Mpinda harvests three or four kilos of chillies and takes them to the market and sells them for 1000 kwacha a kilo ($1.40).
Mpinda has already planned his next step. After harvesting his little patch of eggplant, he is going to clear the land and plant a whole garden of chilli.
Mpinda has also watched the DVD of rice videos, and although no one in the area grows rice, he realizes that the crop would do well in the slightly higher space, just above his rows of vegetables. He has already looked for rice seed: there is none to be found in Mwanza and the agro-dealers wonâ€™t or canâ€™t order it for him, so he is going to travel to the city of Zomba, 135 km away, and buy rice seed there. Mpinda has already identified the major rice varieties grown in Malawi and decided that one of them, Apasa, is the best for highland areas like his.
He is going to plant rice in October, possibly becoming the first rice farmer in Mwanza district.
Mpinda didnâ€™t watch the rice and chilli videos as part of a farmer group. He didnâ€™t have an extensionist to answer questions. He simply had the videos which he could (and did) watch several times to study the content. And this information alone was enough to inspire him to experiment with two crops that were entirely new to him.
You can watch the chilli videos in English here: http://www.accessagriculture.org/search/chilli/all/
And in Chichewa here: http://www.accessagriculture.org/search/chilli/ny/
You can watch the rice videos in English here: http://www.accessagriculture.org/search/rice/en/
And in Chichewa here: http://www.accessagriculture.org/search/rice/ny/
These videos and others are also available in other languages at www.accessagriculture.org
People usually have a good reason for ignoring free advice.
So when Tumpale Pindani, my Malawian colleague, asked me â€śHow long will it take before the people in Malawi accept conservation agriculture,â€ť I could tell that it had already been a long slog, even though I couldnâ€™t answer her question. After all, conservation agriculture has worthy aims, such as improving soil fertility and halting erosion. Conservation agriculture includes many practices, such as minimum tillage, cover crops, and straw mulch. Most of these are old practices, widely used somewhere in the world, although none are used on farms worldwide. Some farmers have competing goals, besides soil conservation.
Tumpale and I were visiting a field in Malingunde, in Central Malawi where Alefa had harvested groundnuts and was about to plant maize. So Alefa was rotating crops, which is one component of conservation agriculture. Alefa asked us how she could improve soil fertility, and Tumpale recommended composted manure, another component. Alefa listened with interest.
On the way back to the car Tumpale stopped and asked me to look at a boy sitting on the ground in a dry field. Most of the ground was bare, except for some spots where the few remaining maize stalks had been piled up, ready to burn. â€śDo you know what he is doing?â€ť Tumpale asked.
â€śHeâ€™s waiting for rats,â€ť Tumpale explained.
The dry season is driest right at the end. And that is when older children look for rat holes. The kids pile up maize stalks where the rats like to hide, and burn the stalks, creating a clear, wide open field of bare earth and ash. There is nowhere for a rodent to hide.
Then the boys dig up the rat holes, and when the rats run out, the boys club them with the hoe, and take their prey home to eat.
Itâ€™s not as terrible as it sounds. Iâ€™ve had rat three times this year so far, twice in Uganda and once in Nigeria. Rat is a treat, especially if grilled on an open fire.
One conservation agriculture practice is to leave crop stubble in the field, where it slowly decomposes, protecting and enriching the soil. Itâ€™s a sensible recommendation. But people arenâ€™t following this suggestion, at least not in Malingunde. During the scorching dry season there is not much else for cattle to eat, so after harvesting the maize, people take the corn stalks home, and feed the leaves to their animals. Women burn the bare stalks as fuel, for cooking. In this part of Malawi crop residues are more valuable at home than in the field.
Stalks that are not gleaned during the dry season may eventually be burned to clear the ground for gourmet rat hunting. Conservation agriculture is marketed as a package, or a brand, but that doesnâ€™t mean that all recommended practices will be adopted. Some will have to take second place to existing needs, like the search for tasty rats.
I was home Thursday evening, when my daughter, Clara, called us outside to see the forest fire. It was dusk and there was a bright, orange patch of flame dancing around the crest of the Andes, above Cochabamba. The jets of flame were so large we could see them leaping high above the tree tops, even from the city, far below on the valley floor. There had been no rain lately, so we imagined that within a few days the whole forest would be burning.
Now here, the word â€śforestâ€ť needs some explanation. This forest is a large swathe of pine and eucalyptus planted on the upper slopes of the Andes in Tunari National Park. Until the twentieth century, the mountain had been covered in native trees: short, gnarled, slow-growing hardwood trees with papery bark, called qhewiĂ±a in Quechua (Polylepis spp.). Throughout the mid twentieth century, wagon loads of the qhewiĂ±a wood were sold as firewood in the city of Cochabamba.
By the 1980s, these native trees were mostly gone. Then the Swiss government financed a project to reforest the mountain. Over the next few years, they planted pines and eucalyptus in the national park on the mountain above the city of Cochabamba, and in and around farm communities in the central departments of Cochabamba and Chuquisaca.
By Friday the fire we had seen from our home was largely out. On Sunday our curiosity got the better of us and with some of the extended family we drove 10 km above the city on a winding, dirt road, and parked at an abandoned pic-nic ground. Looking around, I realized that the Swiss planned Tunari National Park to be a peri-urban, family-friendly recreational park, where people would come for hikes and meetings in the pines. Among the trees above the city, the project left behind some childrenâ€™s playgrounds and brick cabins where people could hold meetings or training courses. The buildings were abandoned years ago. The roofs have started to cave in and someone has stolen all of the rope from the childrenâ€™s swings.
We hiked towards the site of the fire. There were isolated patches of smoldering fire, but no flames. A police fire-truck passed us on the way down, heading for the city. The fire fighters had also decided that the flames were out.
Once in the forest, we could see that the dried grass was thick on the ground, and that seems to have been the main source of fuel for the fire. We thought that some of the trees might survive. This forest has a fire almost every year, during the dry season, and many of the big pines and eucalyptuses have survived earlier burns.
We stopped at a ranger station to get more information. The staff explained that Tunari National Park has seven employees, and they respond as soon as they see a fire. When the fire is too much for the park staff to handle, they call on the departmental branch of the national police (the fire truck we had seen). The park service also relies on an energetic group of volunteers, a membership-based community organization called SAR (Search and Rescue) that looks for lost hikers and operates an ambulance, besides helping to put out forest fires. SAR was founded in 1988 and has no ties to the Swiss project that planted the forest.
By 1999, the original Swiss reforestation project morphed into another project, and no more trees were planted. Yet the original planted forests were not abandoned. The patchwork of organizations (the national park, the police and SAR) that come to the rescue are doing a competent job of saving the trees. The planted trees are now thick and healthy in most places.
The Bolivians put out the forest fires, but donâ€™t care much for the cabins and other buildings left in the forest. I think that is a pattern; when donors invest in tangible, capital goods, local people tend to maintain certain kinds of investments (especially forests), even if the local people are not always willing to maintain buildings and some other investments.