A team of Spanish researchers has proved that the first agricultural systems on the Iberian Peninsula became ever more unsustainable with the passage of time. The study involved the analysis of fossilised grains of wheat and barley from Los Castillejos (Granada), an area of archaeological remains where cereals were cultivated between 4000 and 2500 BC.
Figures revealed by the study, show a reduction of around 35% in the yield of wheat crops and 30% in barley between the years 4000 and 2500 BCE (end of the Bronze Age). The average weight of the grains of these cereals also fell by 10 miligrammes (33%) and 12 mg (38%) respectively. The research also revealed a 33% reduction in the nitrogen content of the wheat grains and 56% in barley.
The results of the study show a link between the decline in the status of the crops and a progressive loss in soil fertility, and reinforce the hypothesis that the first agricultural activities in the Mediterranean area had a negative impact on ecological and environmental conditions there.
The scientists chose the Los Castillejos archaeological site because it shows evidence of a continuous period of cereal cultivation over more than 1,500 years, starting in the Neolithic, when agriculture first appears in the region. However, they have contrasted their data with other results from Arkaute (Álava), Guadahortuna (Granada) and various areas in Catalonia and Castilla-La Mancha, as well as with other sites in Syria and the eastern Mediterranean.
Taken from Science Daily
