Monday, 20 June 2011

Improving soils to combat nutrient deficiency

Improving the nutritional content of staple crops, via the soil, can help tackle malnutrition according to the New Agriculturalist.

The lack of essential micronutrients in the diet, such as iron (Fe), zinc (Zn) and vitamin A leads to malnutrition on a grand scale in parts of the developing world leading to child mortality and mental impairment. Every year, an estimated 400,000 children, predominantly in Asia, die from zinc deficiency alone, nearly as many as die from malaria. Lack of zinc can cause diarrhoea, poor growth, and weaker resistance to infections such as pneumonia.

The report argues that increasing micronutrient concentrations in grain through the use of specially enhanced fertilisers could be a fast and cost-effective way to improve nutritional health among cereal-dependent communities.

Nearly half of the world's cereal production takes place on land with inadequate levels of soil-available zinc, reducing crop yields as well as contributing to poor child health and high mortality rates. Biofortification of staple crops with target micronutrients (zinc, iron and Vitamin A) is now a key focus for the Consultative Group on International Agricultural Research (CGIAR), through its HarvestPlus programme.

The report describes how adding zinc oxide (ZnO) or zinc sulphate (ZnSO4) to a standard (NPK) fertiliser boosts grain yields in rice and wheat, with ZnSO4 also significantly enhancing Zn concentration in the grain. Increasing micronutrient levels in the soil, through enriched fertilisers, is recommended as the quickest and most locally-appropriate way to enhance Zn uptake by plants and people, simultaneously improving crop yields and dietary Zn levels. For the full report, visit the New Agriculturalist website.