IS CROPPING UNDER A CANOPY FRIENDLY TO SUSTAINABLE FARMING?

Agro forestry is becoming increasingly important throughout the world. Data from the Food and Agriculture Organization (FAO) of the United Nations confirms that while the number of trees in forests is still declining every year, the number of trees on farms is steadily increasing.

Agroforestry is not a new practice. It has been used by subsistence farmers throughout most of the world for many generations. The year 2009 Trees on farm study conducted by the world Agroforestry centre found that 48 percent of all agricultural land – which is home to almost a third of the 1.8 billion people – has at least 10 percent trees cover. And six million square kilometers – or 27 percent of agricultural land globally – has more than 20 percent tress cover.

In the last 40 years, agroforestry has become a subject for systematic study and improvement, and a livelihood option promoted by land use managers and international development efforts. Agroforestry systems range from home gardens to subsistence livestock and pastoral systems, on-farm timber production, tree crops of all types integrated with other crops, and biomass plantations. In Tanzania agro forest is practiced in Babati district at Manyara region.

There are multiple livelihood benefits of trees to farmers, in particular smallholders in the developing world, who are the focus of the world Agroforestry Center’s work. Trees provide farmers with a range of products and service; from fruits and nuts to livestock fodder, fuel for heating and timber for housing, medicine and green fertilizers. In numerous countries, including India and Kenya, the majority of the nation’s wood is derived from farm-grown timber.

Additionally, trees grown on farms have environmental benefits in the form of shelter, erosion control, watershed protection, water retention and increased biodiversity. Carbon storage both above-ground and below-ground is greatly enhanced compared to conventional agriculture, thus improving opportunities for rewards in the form of agricultural carbon offsets for farmers. Agroforestry can also enhance resilience to climate variability and climate change. According to the intergovernmental panel on climate change, ‘‘Transformations of degraded agricultural lands to agroforestry has far greater potential to sequester carbon than any other managed land use change``

The United Nations has designated 2011 as the International year of Forest, which is an opportunity to more fully recognize the tremendous importance of agroforestry in a future world. Agroforestry is one of humankind’s best hopes to create a climate-smart agriculture, increase food security alleviate rural poverty, and achieves truly sustainable development.

The Director General of the World Agroforestry Centre, Dr Dennis Garrity has a vision of a future where much of our annual food crop production occurs under a full canopy of trees. Garrity has spent his career developing small-scale farming systems and promoting innovative solutions to natural resource management. His vision is already being fulfilled in many countries in Africa with extremely encouraging results in terms of higher food crop yield and restoration of degraded soils. The challenge that lies ahead is to extend these practices to millions of other poor farmers who desperately need homegrown solutions to their food production problems.

Through what is termed Evergreen Agriculture particular types of trees are intercropped with annual food crops and livestock systems. As most forms of agroforestry, the trees offer multiple benefits to farmers. They can provide source of green fertilizer to build healthier soils and enhance crop production, increase soil fertility by fixing nitrogen in their roots, or provide fruits, medicine, livestock fodder, timber and fuel wood.

In Africa, the most promising results of Evergreen Agriculture come from the integration of fertilizer trees into cropping systems. These trees improve soil fertility by drawing nitrogen from the air and transferring it to the soil through their roots and leaf litter. Scientists have been evaluating various species of fertilizer trees for many years, including sesbania, Gliricidia, Tephrosia and Faidherbia.

The indigenous Africa acacia, Faidherbia albida is perhaps the most remarkable of these fertilizer trees. Faidherbia sheds its nitrogen-rich leaves during the early rainy season and remains dormant throughout the crop-growing period. The leaves grow again when the dry season begins. This make it highly compatible with food crops, because it does not compete with them for light, nutrients, or water during the growing season: only its bare branches spread overhead while the food crops grow to maturity.

In Niger, satellite imagery shows close to 5million hectares of land covered by Faidherbia albida. Millet and sorghum production has been significantly enhanced on this field where up to 160 trees are grown per hectare. In Malawi, maize yield have increased up to 280 percent when they are grown under the canopy of Faidherbia trees. In Zambia 160,000 farmer have conservation farming practices to include the cultivations of food crops within agroforests of Faidherbia trees. Extensive observations have indicated that growing maize in the vicinity of the trees dramatically increases production, and the health of the soils is improved.

Dr. Garrity is quick to point out that framers have recognized the values of these trees for generations. I met women farmers in Malawi who had been growing maize under a full canopy of Faidherbia trees for 20 years, Garrity recalls their yields are three times higher than before they planted the trees.

As scientists, development practitioners and farmers seek innovative solutions to global concerns, the spotlight is being turned towards practices such as Evergreen Agriculture. At a high-level meeting in November 2010 in The Hague, Netherlands, representative from more than 115 countries developed a roadmap for agriculture to meet the challenges of climate change and food security. These ministers of agriculture, government officials, scientists and representatives from civil society organizations and the private sector called for climate smart’ agriculture to address the one third of global greenhouse gas emissions generated by agriculture and deforestation.

Evergreen Agriculture is emerging as an affordable and accessible science-based practice which is both climates smart and able to increase smallholder food production.

“We urgently need to refine, adapt and extend evergreen agriculture and other agroforestry technologies,” say Garrity. “Not just in addressing climate change, but also to drastically improve the incomes and livelihoods of smallholder farmers and help meet the challenge of feeding the world’s projected population of 9 billion by 2050”

WRITTEN BY
ANSELMO WAMI-YET 2011