Five?year field trial of the biomass productivity and water input response of cactus pear (<i>Opuntia</i>spp.) as a bioenergy feedstock for arid lands

Climate-resilient and highly water-use efficient crops are needed to meet the future food, feed, fiber, fuel demands of a growing human population. Cactus pear (Opuntia spp.) productive yet have crop water that approximately 20% traditional due their ability perform crassulacean acid metabolism (CAM). In first long-term field trial Opuntia for bioenergy in United States, aboveground biomass (cladode fruit) productivity response different inputs O. cochenillifera, ficus-indica, streptacantha were evaluated at planting density 1418 plants ha?1 under three irrigation levels over 5-year period investigate inputs. Mean cladode fresh weight, dry count, fruit weight increased linearly by 1.26-, 1.88-, 1.53-, 1.89-, 2.13-fold, respectively, with increasing from 300 716 mm year?1. Significant differences appeared years 4 5 as cactus trees grew larger. However, no significant observed among spp. all parameters measured. Biomass 140.8- 132.5-fold respectively. annual total 300, 407, year?1 input resulted 8.25, 11.16, 15.52 Mg mass year?1, sparse used here separate blocks, which could been easily quadrupled. ficus-indica performed better than cochenillifera terms count quality. was consistent previous studies demonstrating displays very high food/forage potential using substantially lower rates supplemental conventional grown semi-arid arid regions.