American archaeologists believe that the high yield fields of ancient Mayan provided periodically drop down volcanic ash. It is because of this fertilizer on marginal land could be many thousands of people. But is it really? After all, this probably does not help ashes, but rather badly hurting the local soil.
One of the most intriguing mysteries of the prosperity of the ancient city-states of the Maya in the Yucatan Peninsula — this is how these thousands of settlements may have existed in a fairly primitive agriculture in the region is quite infertility. Simply put, it is still unclear where the Maya took as much food to feed a vast urban population, which in itself is not engaged in agriculture. To explain this phenomenon, scientists have so far put forward a variety of hypotheses, including an absolutely fantastic.
Recently, at the conference of the Society for American Archeology Payson Sheets, a scientist from the University of Colorado (USA) suggested that the Mayan farmers actively helped … volcanoes. More precisely, spewing their ashes. His assumption is based on the finding in the ruined Mayan city of Tikal channels (in present-day Guatemala) a large number of mineral smectite.
As you know, this mineral is formed entirely of volcanic ash. The analysis, conducted by a group led by geochemist Ken Tankersley of the University of Cincinnati (USA), showed that his education was not involved African dust carried by air currents to America. That is, this was only the ashes of local production — once it spewed fire-breathing mountains of Guatemala, El Salvador, Honduras, and Mexico. However, while specify which volcano (or volcanoes) was his "parent" does not work — too little material for a more detailed analysis.
At the same time managed to establish the age of the tikalskih smectite. According geochemists they were formed with the year 340 BC. e. to 990 years. It must be noted that the settlement itself, known as Tikal, appeared on the site a little earlier — at the beginning of VII century BC. So if somehow the ashes and helped hard-working farmers that lived around this city, it is clearly not right. And later smectite education abroad coincides with the period when Tikal and its surroundings were finally abandoned. Why is that people throw their garden plots, when the hand they had in abundance as valuable fertilizer?
However, the "Hitch" is not confused Sheets. He put forward the hypothesis that the performance of the agricultural sector is provided Mayan Mesoamerican constant volcanic activity, occasionally delivers on the field as a valuable fertilizer. Sheets estimated that the loss of two millimeters of volcanic sediments was sufficient to enrich the soil for a couple of decades.
At the same time, as part of the by-product of volcanic activity includes very useful elements for the plants in the form of iron and magnesium germination of plants, according to his calculations, increased by three to four times. That is, after loss of "ash" normal rainfall area from which the modern descendants of the Maya collect an average of 7 tons per hectare, was to give 21-28 y / y! Furthermore, according anthropology, small ash particles containing silicates, simply "choked" pests, which also contributed to increased yields.
So, according to the researcher, it is abundant volcanic fertilizers enrich the local soil infertile, which consisted mainly of products of weathering limestone bedrock and a thin layer of humus. That, in turn, made it possible for residents of neighborhoods Tikal produce enough food not only for themselves, but for the hordes of urban "slackers" (according to the calculations of archaeologists at the beginning of our era, the population density of the city is 400-600 people per square kilometer).
So what, is it really for its agricultural successes (and Mayan land tenure system was one of the most highly in the ancient world and the Middle Ages), the ancient Maya were required to volcanoes? Probably not, and here's why. The fact that the volcanic ash can actually be a valuable fertilizer. But only if he misses a thick layer of soil, which are active processes of organic matter decomposition and minerals. And in that place, where more than a thousand years was the city of Tikal, such clearly was not. And next door — too.
The fact that the soil formation process in Central America is rather complicated. On the arid plateaus of Yucatan almost no familiar earthworms of the family Lumbricina, which are the main disintegrants soil in most agricultural regions of the world. They, passing through their intestine weight and organic micronutrients promote uniform mixing of all components of the soil, which makes it more pleasant for the plants. However, do not favor lyumbritsiny very dry places. So there perform their functions more "drought" insect larvae, ants and even termites.
But for them, that's just the volcanic ash is a "weapon of mass destruction" as silicate dust clogs their external openings respiratory system, located, as we remember, on each side of the abdomen. That is, indeed, the "choke". As a result, formed a very different picture: the Yucatan soil as a result of volcanic activity are deprived of their basic "processors", resulting in useful compounds of iron, magnesium, potassium and aluminum, can not simply be used by plants as they are initially difficult to access these forms.
So, there is a fertilizer, but it can not take advantage of — those who could recycle them into easy connection died because of volcanic ash. Moreover, in order to cause the "apocalypse" of soil insects, these same two millimeters per year is more than enough. That is the massive loss of ash was not increased, but on the contrary, strongly reduce the yield of Mayan fields. In such a situation, the residents of Tikal would leave the city before the start of the first millennium AD (when and began the process of formation of smectite).
In addition, in the history of civilizations of Mesoamerica, there are instances when a volcanic eruption and the subsequent release of the ashes was the cause of death of city-states. So, at the beginning of the first millennium BC as a result of increased activity of the volcano Ilopango was abandoned ancient city Chalchuapa (and the volcano itself was far enough away from the city, that is, it was not at all the situation of Pompeii). It is noteworthy that the ash was falling asleep while the surrounding fields in the 1-2 cm layer, that is, according to the hypothesis Sheets, fertilizers would be enough for long. However, none of the residents after the eruption ceased, for some reason do not get this "gift from heaven" — almost five hundred years in the vicinity of Chalchuapy there were no settlements.
A similar thing happened around the same time and with the city Cuicuilco (near Mexico City). It became impossible to live there because of the ash formed during the eruption of the volcano Shitli, covered with a layer of 1 cm all the fields in a radius of 50 km. It was only after 300 years, these areas have been re-settled people. Interestingly, when in 1943 the eruption of the volcano Parikutin, located 320 kilometers west of Mexico City, this tragedy partly reproduced the (then the ashes fell asleep fields of farmers in a radius of 500 kilometers), with at least some harvest abundantly "fertilized" fields could get only ten years (and that with current technology). Many experts believe that the soil is completely recover from this "gifts" only 200 years later, and only then it would be possible to take the same yields as before the eruption.
So, apparently, the ancient Maya, in contrast to modern archaeologists knew that volcanoes are not helping them, and one of the ruin. Therefore, it is unlikely they were happy to fall out of ash in their fields, and especially do not use it as fertilizer. That, in general, did not stop them from their sites to collect a bountiful harvest. But how do they do it?
Most of all, thanks to the judicious use of the method of their plots, which are formed as a result of burning bushes and undergrowth. This region was called milpa. It was known that local farmers through lengthy trials and selection were able to bring hybrid and high yielding varieties of major crops — maize, beans and squash, which turns these milpy they were planted. In addition, the manual technique of processing a small forest area and the combination of crops in the same field a few crops (such as maize and beans) allowed a long time to maintain fertility and did not require frequent change milp. A natural conditions allow Yucatan Mayan farmers gather here on average at least two crops a year.
In addition, in dry regions (including about Tikal), archaeologists have long been using aerial surveys have found distinct traces of the present intensive agriculture: the so-called canals and raised fields — an artificially made long and narrow ridges of land, half flooded by the river. Yields of these fields could be up to 8-10 quintals of maize per hectare. Interestingly, the first such fields appear near Tikal back in the year 229 BC. e. and it was at this time, the city and began to experience the extraordinary cultural and political prosperity. So there seems to be all the same.
In addition, Maya is also very fond of breadfruit "Ramon." This plant is virtually no maintenance required, but gave a significant amount of food. And it should be noted that even in the "classic" period of the Mayan civilization, rural people are actively engaged in gathering wild fruits and edible plants (one of which was such exotica as the maguey cactus). So even in the event of bad harvests of maize and beans food, in general, all missing.
Therefore, most likely, progress and prosperity of the ancient Mayan cities did not occur due to the abundance of volcanic ash, and thanks to the mind, observation and hard work of their inhabitants, as well as farmers who live nearby.
See also: Mysterious ancient artifacts, interesting facts about Antarctica.