M. H. Hirakuri

Life-cycle assessment of the soybean-sunflower production system in the Brazilian Cerrado

PurposeIn the “Cerrado” (Brazilian savanna), sunflower comes mostly from a cropping system where its seeding follows soybean harvest. Soybean has a much higher economic value, but this association with sunflower reduces the environmental impacts from both crops by sharing resources. This study performed a life-cycle assessment (LCA) of the soybean-sunflower cropping system, identified its hotspots, and compared its environmental performance with two hypothetical monocultures, in order to corroborate its benefits.MethodsSoybean-sunflower cropping system inventory used data from farms of the Parecis region, consolidated by experts. Inventories for soybean and sunflower monocultures were estimated from the cropping system inventory. LUC (land-use changes) were calculated from CONAB (2015), FAOSTAT (2012), and Macedo et al. (P Natl Acad Sci USA 109:1341–1346, 2012). Emissions estimation followed Nemecek and Schnetzer (2011), Milà i Canals (2003), and EC (2010). Land occupation, land-use changes, and liming were allocated by occupation time, but a sensitivity analysis was performed for yield and gross margin as allocation criteria. ReCiPe Midpoint (H) v1.12/World ReCiPe H was the impact assessment method, and some categories were disregarded as not relevant. We used pedigree matrix to estimate uncertainties for inventory and Monte Carlo method for impact uncertainty analysis as in Goedkoop et al. (2008). We used SimaPro 8.0.5.13.Results and discussionThe soybean-sunflower cropping system generate relevant human toxicity, freshwater toxicity, freshwater eutrophication, climate change, and terrestrial acidification impacts, related to emissions derived from nitrogen and phosphate fertilizers and emissions generated by LUC. Sunflower-soybean cropping system has better environmental performance when compared to the combination of monocultures because of a number of synergies made possible by sharing land use and other resources. Changing the allocation criteria altered the relative performance of some categories, but in all categories the environmental impacts of the cropping system were lower than those of the corresponding monoculture impacts, regardless of the allocation criteria implemented.ConclusionsWe concluded that the environmental performance of the soybean-sunflower cropping system can be improved by optimizing the use of chemical fertilizers. Climate change impacts, which are mostly driven by LUC, could be reduced by production intensification, preventing the clearing of native vegetation for agricultural purposes. This study confirmed the environmental benefits of cropping systems when compared to monocultures and the advantages of association of nitrogen-fixing legumes with other plant species in a production system.

Euschistus heros (Hemiptera: Pentatomidae) Fitness on Artificial Diets: An Approach to Optimize Mass Rearing of Telenomus podisi (Hymenoptera: Platygastridae) for Augmentative Biological Control

Abstract In order to optimize the mass rearing of Telenomus podisiAshmead (Hymenoptera: Platygastridae) for augmentative biological control we tested the suitability of different artificial diets with respect to egg production of Euschistus heros (F.) (Hemiptera: Pentatomidae). For this purpose, biological parameters of E. heros and T. podisi were evaluated in experimental trial with these diets. All tested artificial diets supported the rearing of E. heros. However, female and adult life history traits including longevity, total oviposition, nymph developmental time, and fertility were altered, with poorer results than under the natural diet. However, because of the higher economic cost of the natural diet, its replacement with artificial diets could be beneficial. Since stink bug reared on artificial diet has shorter lifespan, an alternative to overcome this issue is to replace earlier the insects in the insect facility what could still be cheaper than insects reared on natural diet. It was also noted the possibility of using artificial diets without lyophilized components what can further reduce the cost of rearing.