Satellite imagery to aid in veld production

Satellite imagery to aid in veld production

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South Africa: Satellite images could soon be used in South Africa to quantify veld production, estimate livestock carrying capacity and help farmers plan fodder flow, according to Farmers Weekly report.

The technology used for satellite imagery is widely available and accurate and farmers can benefit from it, said Tony Palmer and Alan Short of the Agricultural Research Council’s Animal Production Institute (ARC-API). Once the technique of converting satellite data into an accurate picture of plant growth (and so of grazing capacity) is refined, researchers can give farmers real-time plant-production estimates for their veld. This will be invaluable for fodder-flow planning in livestock areas. Regional maps will be available from the agriculture department’s Agricultural Geo-referenced Information System (AGIS) at www.agis.agric.za. These maps will help government support farmers during exceptional circumstances, such as droughts.

By measuring surface temperature and atmospheric and soil moisture, satellite-borne sensors can show when conditions are optimal for evapotranspiration (ET), and so for plant growth. Launched in the late 1990s, the Moderate Resolution Imaging Spectroradiometer (MODIS) was designed to give improved ET estimates. The sensor collects data to calculate a normalised difference vegetation index, which is a daily estimate of plants’ active growth. Cloud-free images are then used to prepare an eight-day summary of the leaf-area index, which is the leaf area from which ET can occur.

This relationship between MODIS leaf-area index and actual ET can also predict biomass production in the South African savannah.

Source: Farmers Weekly