Project Highlights

Africa Soils Information System
http://www.africasoils.net

World Agroforestry Centre's Global Research Project on Land Health
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Project featured as CGIAR story of the month (Feb 2006)
CGIAR scientists deploy Infra-Red scanners in fight against hunger: Five developing countries to test new crop-boosting technique... Learn more

The soils lab in a suitcase
A technique previously used by the pharmaceutical industry to ensure quality control in medicines is taking off as a tool that is set to radically transform soil mapping in Africa and beyond... Learn more (See News and media coverage.

Sensing Soil Condition

Assessment of soil condition requires expensive and time-consuming measurements in the laboratory and the field. Many repetitions of the measurements are required to deal with high soil variability. As a result, scientists have been unable to measure and monitor soil condition (soil quality/health) and soil degradation over large areas.

Our Approach Test of Spectral Library Approach

The Project

Sensing Soil Condition is a technological approach for rapid assessment and large area surveillance of soil conditions for plant growth and ecosystem functioning (e.g. hydrological regulation, erosion

regulation, soil biodiversity). The technology is based on rapid screening of soil condition using infrared spectroscopy (IR). Soil properties and soil condition indices are predicted from infrared signatures of soils compiled into spectral libraries. Spectral libraries constructed from soils sampled from georeferenced locations may then used in conjunction with remote sensing imagery to map out soil quality and soil constraints over entire river basins.

Conventional assessments of soil capacity to perform specific production, engineering or environmental functions rely on local calibration of observations on soil functional attributes to measured soil properties. However, soil analyses are expensive and dense sampling is required to adequately characterize spatial variability of an area, making broad-scale quantitative evaluation difficult. Infrared reflectance spectroscopy, especially near infrared spectroscopy (NIR), is now routinely used for rapid non-destructive characterization of a wide range of materials in industry. Although soil scientists have investigated reflectance spectroscopy for several decades, the technology has not been widely taken up and routinely applied in soil studies.

World Food Prize winner Dr. Pedro Sanchez predicts that within a decade most developing countries will be using the technique for soil and plant analysis.

Our research focuses primarily on application of infrared spectroscopy in risk-based approaches to soil evaluation-approaches that explicitly consider uncertainty in prediction and interpretation of soil properties. We are applying these approaches to the development of soil evaluation and monitoring schemes at national and project scales, and in a pan-tropical research programme on the impWorld Agroforestry Centre of land use and land management on soil degradation.

 

In addition, we are developing an integrated approach to the application of infrared spectroscopy to diagnosis of soil, crop and livestock health in tropical developing countries. This involves use of infrared spectroscopy for a wide range of agricultural and agroforestry inputs and products, including: soils, sediments, crop tissues, manures, composts, organic wastes, seeds, feeds and fodders, livestock faecal samples, wood and charcoal, and tree-derived oils. Some of our newest research is investigating use of infrared spectroscopy in the fields of genomics, metabolomics and metabolic fingerprinting. Here, IR is used to study changes in plant biochemical composition in response to plant genetic variation and environmental constraints.