Effect of Long-Term Sugarcane (Saccharum Spp.) Cultivation on Chemical and Physical Properties of Soils in Belize

Abstract

ABSTRACTThe sugarcane industry in Belize is one of the main economic drivers in the country and is therefore of crucial social and environmental importance. This study evaluated the degree of sustainability of commercial sugarcane production in Northern Belize by determining soil parameters (physical and chemical) in three soil layers (0–15, 15–30 and 30–50 cm) and crop profitability relative to years of sugarcane cultivation (4–25 years since land conversion). The parameters evaluated were organic matter (OM), total nitrogen (TN), cation exchange capacity (CEC), available phosphorus (P), potassium (K), pH, dry bulk density (DBD), porosity (ƒ), and water-filled pore space (WFPS). Field interviews were conducted to document management practices, agricultural inputs, production costs, and yield. The results showed that OM and TN in all soil layers studied and CEC in the 30–50 cm layer decreased, and were negatively correlated, with years of sugarcane cultivation. This indicates that prolonged sugarcane cropping has detrimental effects on soil fertility. There was no clear pattern with years under sugarcane cultivation for P, pH, DBD, and K. Yield levels were maintained by intensification of cultivation, e.g. high inputs and regular replanting, providing short-term benefits at the expense of deterioration of soil fertility. The benefit to cost (B:C) ratio of sugarcane production in Northern Belize was marginal for American Sugar Refinery/Belize Sugar Industries (ASR/BSI), representative of intensive agriculture; and not profitable for small-scale farmers, 1.0 and 0.63 for plantation establishment and 1.2 and 1.0 average for the following six years of ratoon, respectively.