afrol News / SciDev.Net, 23 March - Malawi will this year implement a 'fertiliser trees' project to reduce the amount of fertiliser needed by smallholder farmers. Fertiliser trees are varieties of shrubs that capture nitrogen from the air and transfer it to the soil, a process known as nitrogen-fixing.

The trees restore nutrients and increases crop productivity, as do chemical fertilisers that mainly are based on nitrogen. Scientists hold that the project has a potential of doubling or tripling harvests.

The trees can be interplanted with crops for 1-3 years before being cut and left to decompose, providing fuel and more fertiliser.

Policymakers and agricultural scientists drew up plans for implementing the programme at a conference last month.

The project will target 200,000 farmers, representing ten percent of the agricultural sector, and will start in August, according to Festus Akinnifesi, Malawi's senior tree scientist and country representative of the South African Development Community (SADC) and World Agroforestry Centre (ICRAF).

Mr Akinnifesi says the farmers will receive free tree seeds, an information kit and training on the system and associated crop husbandry.

According to Jeffrey Sachs, director of the UN Millennium Project, fertiliser trees are among the most promising means for achieving the Millennium Development Goal of halving global hunger by 2015.

There are four fertiliser tree systems, all of which are based on improved fallowing - allowing soil to recover nutrients. Malawi is planning to adopt all four systems depending on the type of land.

The first system is sequential planting of nitrogen-fixing trees such as Sesbania sesban and Tephrosia vogelli with maize, shortening the amount of time land needs to lie fallow. In the second, Gliricidia sepium is planted along with maize and coppiced - heavily pruned - during maize growth to prevent competition.

The third involves planting nitrogen-fixing trees a few weeks after maize to reduce competition between the plants. In the fourth, leaves of trees are used as fertiliser for vegetable crop production in the wetlands and maize production in the uplands.

More than 300,000 farmers are currently using fertiliser trees in five SADC countries - Malawi, Mozambique, Tanzania, Zambia, and Zimbabwe. The experiments have so far proven rather successful.

By Deogratias Mmana

© afrol News / SciDev.Net

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