According to FAO, in the last thirty years a quarter of all agricultural land has become less fertile as a result of erosion, silting, soil exhaustion or other forms of land degradation. If these problems were addressed in northern China, food production there could be boosted by 25 per cent. Regional governments need to pay more attention to soil and learn from how soil restoration measures in other parts of the world have helped to increase crop yields. This is the outcome of a study by (a.o.) ISRIC and Wageningen University.
A group of international researchers from the Netherlands (ISRIC and Wageningen University), Austria, China, South Africa, Switzerland, Malawi and Iceland, led by ISRIC – World Soil Information in Wageningen suggest that this is the way forward in an article published in the November issue of Current Opinion in Environmental Sustainability. The article (see attach) appears on the eve of the first Global Soil Week, which takes place from 18-22 November 2012 in Berlin. Policymakers and soil experts will meet to discuss plans for a coordinated approach to combatting land degradation.
Land degradation is a problem in the arid parts of the tropical and subtropical countries, which are home to over one and a half billion people. Erosion, caused by water and wind, and soil exhaustion are responsible for severe losses. Aware of this problem, 193 countries signed a UN Convention against land degradation and desertification (UNCCD) in 1991. Since then research groups have been assessing the costs of land degradation. In a catchment area in China, Chinese and Dutch researchers have assessed that the food production could be at least 25 percent higher if erosion and salinization were mitigated by the introduction of conservation practices such as dams, terracing, mulching or agroforestry.
So far however, these efforts have been insufficient to motivate governments and companies to invest in soil, the researchers conclude. One of the problems is that data on degraded areas, usually based on analyses from soil profiles or satellite photos, are not always unambiguous. There is no one agreed-upon definition of land degradation, and different institutes have their own ways of collecting and interpreting data. Estimates of the annual costs incurred from erosion in Europe alone range from 700 to 14,000 million euros.
The researchers say it has now become easier to collect, interpret and present data because of new technologies and more advanced software. With the more accurate assessments - which are accessible online - regions can learn from the conservation practices in comparable areas. They can see what benefits soil recovery practices have brought and what measures have worked. A start has already been made with databanks such as WOCAT, which ISRIC helped set up. The databank includes descriptions of over 450 soil and water conservation practices that have been implemented, and in many cases the positive effects on food production have been recorded too. ‘There is no ‘one fits all’ solution’, the researchers write. ‘In each region local stakeholders have to decide what works best for them.’’