Between 20% and 50% of nine biomes have been transformed into croplands.
There are many other examples.The knowledge and experience of the remaining indigenous people in the tropics can contribute decisively to increasing food production in the tropics—and in ways that will not destroy the croplands within a generation or two.ANTON HAUGEOsloSIR Mr Sachs provides a vivid interpretation of how structural difficulties handicap tropical countries.
More efficient photosynthesis means less evaporation from croplands.
As you pointed out, there is little arable land available and creating new croplands by continuing to destroy rainforests and fragile ecosystems is a cure worse than the disease.Warren KingPresidentWellSpring ManagementOak Park, IllinoisChina risingSIR – I read your leader on a "snarling China" with interest ("Angry China", May 3rd).
This could be achieved simply by growing trees on degraded croplands and grasslands, an approach known as agroforestry.
Many croplands that once produced sorghum and millet seeds, on which the great Indian bustard thrived, have become fields of sugarcane and cotton or grape orchards.
In addition, poor farming practices have greatly increased nutrient and pesticide runoff from croplands, and sewage effluent and runoff from cities have exacerbated the problem.
It measures the requirements for productive areas (croplands, grazing lands for animal products, forested areas to produce wood products, marine areas for fisheries, built-up land for housing and infrastructure, and forested land needed to absorb carbon dioxide emissions from energy consumption).
The nests themselves are simple and often are located in depressions made in the soil in low croplands and grasslands or are situated on open, rocky ground.
The Earth's croplands, which cover about 15 million square km (5.8 million square miles), are mostly deforested land.
More than 11 million square km (4.2 million square miles) of present-day croplands receive enough rain and are warm enough to have once supported forests of one kind or another.
