Friday, 16 August 2013

IN THE FIELD - In search of 'soil security' in the Pacific islands

Dr Richard Markham, ACIAR's Research Program Manager for Pacific Crops, recently visited Kiribati to check progress on a project aiming to improve the health of the local people and their soil...
Atolls like Kiribati may look appealing to visitors, but achieving food security
can present a serious challenge to the inhabitants, especially in the face of climate change

The threat posed by climate change to food security and livelihoods in the Pacific islands has been widely recognized - and indeed dramatised by the prospect that some islands may actually disappear as sea levels rise. However, there is a wider and more insidious threat to local food production in this region: the loss of soil and soil fertility. Although horticulture has been a mainstay of Pacific island communities for thousands of years, the threat to soils is mainly of recent origin, arising from population growth, deforestation and the intensification of crop production for commercial purposes – and there is little traditional knowledge to help farmers deal with these new circumstances. The loss of soil threatens not only the productivity of crops but also, through run-off into the sea, damages the coral reefs on which island communities largely depend for their protein.

Kiribati men shred cardboard cartons and women collect fresh leaves
(in background) to combine with pig manure to make compost
Atoll countries such as Kiribati face a number of challenges to achieving food security and improving the well-being of their people. Changes in the economic environment have not helped: the falling price of copra (their main export), over-exploitation of fish stocks, mainly by foreign vessels, and rising transport costs have been especially damaging. Diets in Kiribati (and other atolls of Micronesia and Polynesia) have traditionally been based on fish and other sea creatures, accompanied by starchy staples (giant swamp taro and breadfruit), with some fruits (especially Pandanus) but not many greens (e.g. te buka Pisonia grandis leaves in Kiribati).

Increases in cash income and urbanisation have led to a deterioration in the diet, with increasing importation and consumption of white rice, wheat flour and sugar, as well as fatty meats and oils, leading to a catastrophic rise in non-communicable diseases, particularly heart disease, hypertension and diabetes.
Improving the productivity of horticulture faces a number of challenges. Soils in the atolls tend to be shallow, sandy or rocky, exceedingly alkaline, and low in organic matter (leading to low retention of water and nutrients). Intermittent droughts and incursions of sea water make matters worse. The lack of surface water, and the risk of contaminating the limited groundwater beneath the islands with agrochemicals adds a further complication. In Kiribati, this threat to drinking water supplies has led to a ban on all synthetic fertilisers and pesticides.

A Kiribati community group established by the project
visits one another's compounds weekly to make compost
and see how their vegetables are growing
ACIAR's Soil Health project is working with communities in Kiribati on making compost and increasing the production of vegetables, for home consumption and sale. In this project we are thus addressing both issues of poor soil health and poor human health from inadequate nutrition. Various compost mixes and procedures are being tested at eight sites, and early results look promising in terms of improving the soil and boosting vegetable production. Training activities have also been successfully held to build capacity of local researchers in measuring soil components, and to teach growers about soil health and composting methods.
The Kiribati research is part of a larger project aimed at improving crop production and related soil health problems for smallholder growers in the Pacific. To date, most of this work has been done in Fiji. In such 'high' islands of volcanic origin, the nature of the soil crisis is rather different: farmers have intensified production of crops for export, without taking adequate measures to replenish soil fertility. Traditional growing practices in Melanesia relied on long bush-fallows to restore soil fertility. But current growing practices and population pressure allow no time or space for this, and the farmers have no traditional knowledge that helps them actively manage their soils. In both Kiribati and Fiji the symptoms of the crisis are similar – disastrously depleted organic matter – and the imperative is the same: to find ways to restore soil organic matter and, with it, the soil's physical, chemical and biological properties.
The 'fruits' of their labour: prize cabbages
Because a fundamental change in practices is needed, the project emphasises the use of participatory methods of research and learning. The ACIAR research team is helping farmers understand the principles of soil health: that is, how soil properties and biological activity relate to low yields, excessive losses to pests and diseases, and other problems. In the other direction, this participatory approach is helping researchers understand what farmers are prepared to do: for instance, are they ready to invest in fertiliser or in labour to gather up organic residues? Further research is aiming to understand the pest and disease problems better. For instance, what are the commonly seen 'root rots' in taro? What are the pathogens responsible? Where are they coming from?
Project staff visit a successful Kiribati 'commercial' farmer - his relatively
substantial house was financed largely from selling vegetables
Formal trials are held on-farm and on research stations to test various technologies that could improve soil health, including fallows using the leguminous cover crop Mucuna pruriens (velvet bean), locally available soil amendments (residues from ground-up coconut palms and multi-purpose trees, biochar, seaweed, etc.), and (in Fiji) conventional fertilisers. The researchers monitor these trials to understand the impacts on soil fertility and yield, and also on soil-borne pathogens, nematodes, weeds, and insect pests. The 'best-bet' technologies and practices are iteratively tested by farmers in simple, farmer-managed trials. The trials are jointly monitored and discussed by farmers, researchers and extension workers and the lessons learned are applied in further trials to improve the production system.

An innovative farmer prepares his compost in underground pits
(probably retaining more of the organic matter and nutrients than conventional
composting). His son chews a Pandanus fruit, rich in carotenoids.
Complementary ACIAR research projects are addressing the availability of appropriate crop varieties, post-harvest and market issues, and awareness of the link between nutrition and health. Our efforts in Kiribati are currently on a small scale and in their early stages. But there has already been some enthusiastic adoption of the ideas by local communities, and based on the success in Fiji, we are hopeful for great things yet to come.

By Dr Richard Markham, Research Program Manager for Pacific Crops
(All photos also courtesy of Richard)

More information:
Project PC/2009/003 Improving soil health in support of sustainable development in the Pacific
Medium-term research strategy for Kiribati

1 comment:

  1. The threat posed by climate change to food security and livelihoods in the Pacific islands has been widely recognized - and indeed dramatised by the prospect that some islands may actually disappear as sea levels rise. security cages

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