Deficit Irrigation of Forage Cactus (<i>Opuntia stricta</i>) with Brackish Water: Impacts on Growth, Productivity, and Economic Viability under Evapotranspiration-Based Management
Francisco Mardones Servulo Bezerra,
Claudivan Feitosa de Lacerda,
Aelton Biasi Giroldo,
Eduardo Santos Cavalcante,
Nicola Michelon,
Giuseppina Pennisi,
Jonnathan Richeds da Silva Sales,
Carla Ingryd Nojosa Lessa,
Silvio Carlos Ribeiro Vieira Lima,
Fernando Bezerra Lopes,
Giorgio Gianquinto,
Francesco Orsini
Affiliations
Francisco Mardones Servulo Bezerra
Agricultural Engineering Department, Federal University of Ceará, Fortaleza 60455-760, CE, Brazil
Claudivan Feitosa de Lacerda
Agricultural Engineering Department, Federal University of Ceará, Fortaleza 60455-760, CE, Brazil
Aelton Biasi Giroldo
Federal Institute of Education, Science, and Technology of Ceará, Crateús 63705-260, CE, Brazil
Eduardo Santos Cavalcante
Agricultural Engineering Department, Federal University of Ceará, Fortaleza 60455-760, CE, Brazil
Nicola Michelon
Istituto Italo–Latino Americano, Via Giovanni Paisiello 24, 00198 Roma, Italy
Giuseppina Pennisi
Research Centre in Urban Environment for Agriculture and Biodiversity (ResCUE-AB), Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum University of Bologna, Viale Fanin, 44, 40127 Bologna, Italy
Jonnathan Richeds da Silva Sales
Agricultural Engineering Department, Federal University of Ceará, Fortaleza 60455-760, CE, Brazil
Carla Ingryd Nojosa Lessa
Agricultural Engineering Department, Federal University of Ceará, Fortaleza 60455-760, CE, Brazil
Silvio Carlos Ribeiro Vieira Lima
Secretariat of Economic Development of the State of Ceará, Fortaleza 60811-341, CE, Brazil
Fernando Bezerra Lopes
Agricultural Engineering Department, Federal University of Ceará, Fortaleza 60455-760, CE, Brazil
Giorgio Gianquinto
Research Centre in Urban Environment for Agriculture and Biodiversity (ResCUE-AB), Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum University of Bologna, Viale Fanin, 44, 40127 Bologna, Italy
Francesco Orsini
Research Centre in Urban Environment for Agriculture and Biodiversity (ResCUE-AB), Department of Agricultural and Food Sciences (DISTAL), Alma Mater Studiorum University of Bologna, Viale Fanin, 44, 40127 Bologna, Italy
Climate change significantly impacts agriculture and forage production, requiring the implementation of strategies toward increased water and energy use efficiency. So, this study investigated the yield of forage cactus (Opuntia stricta (Haw.) Haw) under different irrigation depths using brackish groundwater (1.7 dS m−1), whose management was based on reference evapotranspiration (ETo) estimated by the Hargreave–Samani (HS) and Penman–Monteith (PM) equations. The research was conducted in Independência, Ceará, Brazil, under the tropical semi-arid climate. A randomized block design in a 2 × 5 factorial scheme was employed, varying the ET0 estimation equations (HS and PM) and irrigation levels (0; 20; 40; 70; and 100% of total required irrigation—TRI). Growth, productivity, and water use efficiency variables were evaluated at 6, 12, and 18 months after treatment initiation. The economic analysis focused on added value, farmer income, and social reproduction level. The results showed no isolated effect of the equations or their interaction with irrigation depths on the analyzed variables, suggesting that irrigation management can be effectively performed using the simpler HS equation. Furthermore, there was no statistical difference between the means of 100% and 70% TRI as well as between 70% and 40% TRI for most variables. This indicates satisfactory crop yield under deficit irrigation. Dry matter productivity and farmer income at 12 months resulting from complementary irrigation with depths between 40% and 70% of TRI were significantly higher than under rainfed conditions. The 70% depth resulted in yields equivalent to those at 100% TRI, with the social reproduction level being achieved on 0.65 hectares in the second year.
