Economic and energetic analysis of cactus pear biomass production systems with increasing levels of technological intensity

The forecasted expansion of arid and semi-arid lands worldwide due to climate changes requires alternatives for economically viable agricultural cropping systems to produce biomass for food and energy purposes under water-limited environments and with low emissions of greenhouse gases (GHG). The cultivation of cactus pear (Opuntia cochenillifera) may be a viable alternative for biomass production in water-limited environments, to be used as animal fodder, or for energy purposes. Usually, cactus pear is cultivated using low technological inputs, such as mechanization and fertilization, but a growing number of farmers have been adopting management practices with greater inputs. Thus, the study aims to analyze the economic and energetic viability of the biomass pro-duction of cactus pear biomass production systems with increasing levels of technological inputs in the semiarid region of northeast (NE) Brazil. The research was carried out with primary data covering seven states in NE Brazil, under three levels of cropping system technological intensity: A) low; B) medium; and C) high techno-logical intensity, based on the different inputs of mechanization, fertilization, irrigation, and other variables. A semi-structured questionnaire was applied to 54 farmers to collect data about crop management practices and biomass productivity of cactus pear production systems. Energy balances were carried out using the energy return on investment (EROI) method, and the economic analysis used a deterministic approach based on the criteria of Net Present Value (NPV), Internal Rate of Return, and Discounted Payback. The risk was analyzed through sensitivity and stochastic Monte Carlo simulation analysis. System A had the lowest energy expenditure and biomass productivity, resulting in an EROI of 4.42, and the lowest NPV return, with a 94.7% probability of economic viability. System B had an EROI of 3.60, therefore, the lowest economic viability (90.1%). System C stood out with the highest energy expenditure and biomass productivity, resulting in the highest EROI (5.26), economic return, and probability of viability (99.4%). Energy return of high intensity systems reached maximum values when chemical fertilization and irrigation were included (EROI of 6.14). Therefore, the high-intensity production system proved to be the most economically and energetically efficient and the most viable alterna -tive for large-scale biomass production, regardless of the use of biomass for animal feed (fodder) or the pro-duction of biofuels. However, less productive, low-intensity systems are also energetically and economically viable and are easily accessible to small rural producers, which is an important result that supports the use of this crop in regions prone to desertification. The study contributes to the development of sustainable practices in the production of biomass in the semiarid region of Brazil and offers policymakers and stakeholders in the energy sector novel and useful information about the potential of cactus biomass as a renewable feedstock for biofuel production in the Brazilian semiarid region and other dry regions around the globe.