Soil Chemical Property Changes in Response to Long‐Term Pineapple Cultivation in Costa Rica

Abstract

Core Ideas Soil organic C was lower under pineapple cultivation than in an adjacent pasture and secondary forest. Soil organic C did not differ between 7‐ and 20‐yr‐old pineapple fields. Soil pH and base cations were lower in a 20‐ than in a 7‐yr‐old pineapple field, pasture, and forest. Anion exchange capacities were larger in soils under pineapple cultivation than in pasture soils. Pineapple cultivation may require increased liming rates to help maintain long‐term soil quality. Pineapple [Ananas comosus (L.) Merr.] has been cultivated in Costa Rica for decades on land previously under forest and pasture vegetation. A pineapple plantation in Costa Rica was chosen to investigate the impact of long‐term pineapple cultivation on soil chemical properties. Soil samples were collected at pineapple sites under cultivation for 7 and 20 yr, as well as in an adjacent pasture and secondary forest. Samples were analyzed for extractable nutrients, total C and N, and cation and anion exchange capacities (CEC and AEC, respectively). Soil organic carbon (SOC) and soil N concentrations did not differ (P > 0.05) between the 7‐ and 20‐yr‐old pineapple sites nor between the pasture and forest sites in the top 20 cm. However, the average SOC concentration in the pasture and forest sites was 1.5 times greater (P < 0.05) than that in the pineapple sites. Soil AEC was 3.5 times greater (P < 0.05) in the top 10 cm of both pineapple sites than in the pasture. The 20‐yr‐old pineapple site, which had a soil pH of 4.1, had 2 to 13 times greater (P < 0.05) exchangeable acidity and 2 to 5 times lower base cation concentrations in the top 20 cm than the 7‐yr‐old pineapple, pasture, and forest sites. The greater acidity and lower base cation concentrations in the older pineapple site suggest that agronomic management practices may need to be adjusted to minimize negative changes in soil chemical properties and help maintain future soil productivity.