you're reading...
Anthropology, Archaeology, Climate, Culture, Environment, Evolution, LifeScience

Agronomic conditions in ancient Near East 12,000 years ago

Researchers describe the characteristics of agriculture at its beginnings by comparing kernel and wood samples from ancient Near East sites —- the birthplace of Western agriculture — with present day samples. It is the first time that direct evidences enable to know humidity and fertility conditions of crops, as well as the process of cereal domestication developed by humans from the Neolithic (12,000 years ago) to early Roman times (around 2,000 years ago).

The study is co-headed by the University of Barcelona and the University of Lleida, together with the Archaeological Museum of Catalonia. Credit: Josep Lluís Araus, UB.

The study is co-headed by the University of Barcelona and the University of Lleida, together with the Archaeological Museum of Catalonia.
Credit: Josep Lluís Araus, UB.

Researchers used crop physiology techniques to analyse archaeobotanical remains. In total, they analysed 367 kernels —for instance, barley and wheat—, and 362 wood samples obtained in eleven archaeological sites from Upper Mesopotamia, which includes present south-eastern Turkey and northern Siria, to the Near East. Studied kernels belong to present crops of wheat and barley species that are similar to the archaeological remains found in the region.

 

Progressive domestication

Researchers compared the size of kernel remains with present samples to determine the evolution of crop domestication. “The methodology used to date does not reproduce real size; it measures width and long of charred kernels”, explains Josep Lluís Araus, professor from the Department of Plan Biology of UB. “We have reconstructed cereal kernel weight —adds the expert— and seen that it increased for a longer period of time than it was thought, probably during several millenniums”. According to the researcher, the initial selection of kernel was “unconscious”, in other words, first farmers selected the biggest kernels, so size increased progressively.

 

Wetter and more fertile soils

Sample analysis of carbon and nitrogen isotope compositions —a technique used in crop physiology and improvement— was a key factor to describe the conditions of the area. On one hand, “Carbon isotope composition enables to evaluate water availability for crops. It reached its maximum level 9,000 years ago, and then it decreased progressively until the beginning of our times”, points out Araus. In any case, researchers have not found conclusive evidences about the use of irrigation as a common practice. “This information together with cereal kernel weight allows assessing the productivity of ancient crops”, highlights Josep Lluís Araus.

On the other hand, nitrogen isotope composition provides information about soil’s organic matter and fertility. Juan Pedro Ferrio (Agrotecnio-UdL) affirms that “although they were dryland crops, it can be affirmed that nitrogen was much more available than today: undoubtedly, soils were much more fertile than nowadays”. Moreover, it can be observed a progressive decrease of soil fertility, probably due to over-exploitation or the use of less fertile soils, but also to more extreme climate conditions.

These data enable to describe more precisely agronomic conditions and the evolution of human populations linked to agricultural practices. “The study relates conditions like water availability or soil fertility to crops yield”, states Josep Lluís Araus. Past yields, compared with average calorie needs of one person, enable, for example, to have a rough idea of the crop area needed to feed the population. “This information —adds Araus— can be used to know more precisely the borders of past settlements and the evolution of human communities. The aim is to include all this information in models in order to better understand the past”, concludes the researcher.

Reference: José L. Araus, Juan P. Ferrio, Jordi Voltas, Mònica Aguilera, Ramón Buxó. Agronomic conditions and crop evolution in ancient Near East agriculture. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4953

Advertisements

Discussion

No comments yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Science forum

%d bloggers like this: