Agricultural intensification and changes in cultivated areas, 1970–2005

摘要: Does the intensification of agriculture reduce cultivated areas and, in so doing, spare some lands by concentrating production on other lands? Such sparing is important for many reasons, among them enhanced abilities released to sequester carbon and provide environmental services. Difficulties measuring extent spared land make it impossible investigate fully hypothesized causal chain from agricultural declines then increases land. We analyze historical circumstances which rising yields have been accompanied areas, thereby leading land-sparing. use national-level United Nations Food Agricultural Organization data trends cropland 1970-2005, with particular emphasis 1990-2005 period, 10 major crop types. Cropland has increased more slowly than population during this but paired occurred infrequently, both globally nationally. was not generally decline or stasis area at a national scale time except countries grain imports conservation set-aside programs. Future projections abandonment ensuing services cannot be assumed without explicit policy intervention.