“About a third of the world’s soils are degraded because of soil erosion, contamination, urbanization and other issues,” but planting pulses like lentils and chickpeas could help, says Reuters, quoting a U.N. Food and Agriculture Organization report.
Those numbers represent a rise from the early 1990s, when soil degradation hovered between 16 and 24 percent, says Ronald Vargas, soils and land officer at the U.N. agency, and co-editor of the report.
Repairing the world’s weakened soils would take 15 years, but planting pulses could go far in returning nutrients like nitrogen to the ground and holding topsoil and water in place in between market crops. “Cereals grown after pulses yield 1.5 tons more per hectare, equivalent to adding 100 kilos of nitrogen fertilizer,” said Reuters, citing the FAO report. One study in India found that planting pigeon peas decreased soil runoff and erosion by 59 percent.
Wind, rain and heavy machinery are the greatest sources of soil erosion — the world currently loses soil 10 to 20 times faster than it is replaces it, says the FAO report. But nature is slow to build up fresh soil, taking between 100 and 1,000 years to produce just 1 centimeter of soil naturally. It’s a centimeter that, if not properly maintained, can quickly be lost in a storm, Vargas told Reuters.