[Just as I suspected, J. Donald Hughes's CNS article "The Classic Maya Collapse" was based on dated scholarship. Actually, Hughes's article turns out to be impressions of his vacation in Mexico, not much more substantial than my "London Calling" post. More recent scholarship has refuted this notion of wasteful use of soil and other resources, especially that presented by Robert J. Sharer in the 892 page "The Ancient Maya", which I recommend to anybody interested in the topic. Sharer is Professor of Anthropology, and Curator of the American Section of the University Museum and Anthropology at the University of Pennsylvania. He reads Mayan hieroglyphics and began work on the 5th edition of "The Ancient Maya" in 1980, which was finally released in 1994 after 15 years of research.] A variety of ecological disasters has been proposed to explain the Maya demise. The earliest pointed to the harmful consequences of swidden agriculture, which is believed to have been the basis of lowland subsistence at one time. Its arguably destructive long-term effects on soil fertility and in turn the gradual conversion of forested areas into savanna grasslands have been used to explain the failure of Classic Maya civilization. Since the Maya had no tools with which to cultivate the grasslands, so this argument goes, farmers would eventually have been forced to abandon the central lowlands. Other supposed effects of swidden cultivation in combination with the heavy tropical rainfall of the lowlands were severe erosion and the deposition of soil into what would formerly have been shallow lakes, yielding the swampy depressions (bajos) found in many areas of the lowlands today. The question whether or not all these depressions were originally shallow lakes, at least within the span of Maya civilization, is yet to be resolved. In any event, the ecological-disaster theories based on swidden cultivation can no longer be supported, given the recent evidence that the agriculture practiced by the ancient Maya was both diversified and intensive... The intensive agricultural methods known or suspected to have been used by the ancient Maya include continuous field cultivation, household gardens, arboculture, and hydraulic modifications. In continuous field cultivation, crops are grown with fallow periods of sufficiently short duration that the fields do not become overgrown, a method that requires constant labor to weed out the competitors of the food crops. At least in areas with well-drained, fertile soils and plentiful rainfall, the ancient Maya could have practiced this method of cultivation. Prime candidates for this method would have been alluvial valleys, like those found in various parts of the southern and coastal lowlands. There, on the natural river levees and on the older terraces (of former riverbeds) found above the localized or extensive floodplains of such rivers as the Usumacinta, the Motagua, the Belize, and their tributaries, continuous field cultivation would have been very productive; periodic flooding in these areas would replenished soil fertility by depositing new alluvial soils. The lowest portions of active floodplains (backswamps) are often too wet for too much of the year to allow cultivation without hydraulic modifications (see below). Where older alluvial soils were no longer being replenished by flood deposits, their nutrient depletion could have been controlled by proper intercropping... Louis Proyect (http://www.panix.com/~lnp3/marxism.html)
