Impact of Erythroxylum coca cultivation on soil quality in the Aguaytia valley, Peru

Abstract

In Peru and other countries, E. coca leaf is cultivated for its transformation into cocaine; this process includes the use of insecticides, herbicides and monoculture systems, which generate negative effects on the soil and environmental damage little treated by researchers. The research evaluated the potential effects, through modeling, of E. coca cultivation on physicochemical indicators and soil quality indices (SQI) in the Aguaytia valley, Padre Abad province, Ucayali region, Peru. Areas with E. coca cultivation of 2 (CO2) and 15 years (CO15), ex-coca with natural regeneration of 9 years (EC9), and secondary forest (BS) were evaluated as reference; evaluating soil physical and chemical indicators. The results show differences in all the soil indicators evaluated, except K+. The principal component analysis determined that the indicators clay, sand, silt, MO, N, Ca2+ and SAl were relevant and explained 82.97% of the total variance. In addition, the modeling shows that 15-year-old E. coca has a negative impact on sand, clay and Ca2+, and a positive impact on silt and SAl, but no statistically significant impact on OM and N. The soils presented low quality for BS and very low quality for CO15. In conclusion, the modeling and the ICS show that the cultivation of Erythroxylum coca under monoculture has a significant negative impact on Ca2+ and positive impact on Al3+, %AC, %SAl, % of silt, which caused a loss in soil quality, in addition, recovery is observed in the area of excoca with 09 years of natural regeneration.