Soil fertility and nutritional status of coffee grown in CO2‑enriched atmosphere

Abstract

The objective of this work was to evaluate the effects of atmospheric CO₂ levels on soil chemical attributes, in rows (coffee crop) and between rows (Urochloa decumbens), and on macronutrient contents in coffee leaves. A randomized complete block design was used, in a split‑plot, with six replicates. The treatments consisted of two CO₂ levels in the atmosphere, 390 and 550 μmol mol^‑1. Soil samples were collected in and between coffee rows in 2013 and 2014, at the soil layers of 0–5.0, 5.0–10, 10–20 and 20–40 cm, and of 0–10, 10–20 and 20–40 cm, respectively. Soil pH, Ca²⁺, Mg²⁺, available K, P, and S contents, base saturation, and soil organic matter were evaluated. In 2013 and 2014, a reduction in available P contents was observed in coffee rows as the CO₂ levels in the air were increased. In 2014, soil available K contents were reduced and K contents in coffee leaf were increased under 550 μmol mol^‑1 CO₂. In coffee grown in atmosphere enriched with CO₂, soil available P content is more reduced, which indicates the need of an adequate replacement of this nutrient.