Agriculture and forest: A sustainable strategy in the Brazilian Amazon.

Large-scale agriculture is increasing in anthropogenically modified areas in the Amazon Basin. Crops such as soybean, maize, oil palm, and others are being introduced to supply the world demand for food and energy. However, the current challenge is to enhance the sustainability of these areas by increasing efficiency of production chains and to improve environmental services. The Amazon Basin has experienced a paradigm shift away from the traditional slash-and-burn agricultural practices, which offers decision makers the opportunity to make innovative interventions to enhance the productivity in previously degraded areas by using trees to ecological advantage. This study describes a successful experiment integrating the production of soybean and paricá (Glycine max L. and Schizolobium amazonicum) based on previous research that indicated potential topoclimatic zones for planting paricá in the Brazilian state of Pará. This paper shows that a no-tillage system reduces the effects of drought compared to conventional tillage still used by many farmers in the region. The integrated system was implemented during the 2014/2015 season in 234.6 ha in the high-potential zone in the municipality of Ulianópolis, Pará. Both soybean and paricá were planted simultaneously. Paricá was planted in 5 m x 2 m inter-tree spacing totaling 228x103 trees per hectare and soybean, in 4 m x 100 m spacing, distributed in nine rows with a 0.45 m inter-row distance, occupying 80% of the area. The harvested soybean production was 3.4 t ha-1, higher than other soybean monocultures in eastern Pará. Paricá benefited from soybean fertilization in the first year: It exhibited rapid development in height (3.26 m) and average diameter (3.85 cm). Trees and crop rotation over the following years is six years for forest species and one year for each crop. Our results confirm there are alternatives to the current production systems able to diminish negative impacts resulting from monoculture. In addition, the system provided environmental services such as reduced soil erosion and increased carbon stock by soil cover with no-tillage soybean cultivation. The soybean cover contributes to increased paricá thermal regulation and lower forestry costs. We concluded that innovative interventions are important to show local farmers that it is possible to adapt an agroforest system to large-scale production, thus changing the Amazon.

Adaptability and phenotypic stability of soybean cultivars for grain yield and oil content.

ABSTRACT. The aim of this study was to verify the adaptability and stability of soybean cultivars with regards to yield and oil content. Data of soybean yield and oil content were used from experiments set up in six environments in the 2011/12 and 2012/13 crop seasons in the municipalities of Patos de Minas, Uberaba, Lavras, and São Gotardo, Minas Gerais, Brazil, testing 36 commercial soybean cultivars of both conventional and transgenic varieties. The Wricke method and GGE biplot analysis were used to evaluate adaptability and stability of these cultivars. Large variations were observed in grain yield in relation to the different environments studied, showing that these materials are adaptable. The cultivars exhibited significant differences in oil content. The cultivars BRSGO204 (Goiânia) and BRSMG (Garantia) exhibited the greatest average grain yield in the different environments studied, and the cultivar BRSMG 760 SRR had the greatest oil content among the cultivars evaluated. Ecovalence was adopted to identify the most stable cultivars, and the estimates were nearly uniform both for grain yield and oil content, showing a variation of 0.07 and 0.01%, respectively. The GGE biplot was efficient at identifying cultivars with high adaptability and phenotype stability.

Plant density and mineral nitrogen fertilization influencing yield, yield components and concentration of oil and protein in soybean grains.

There are few studies on the interaction between soybean plant density and nitrogen fertilization. This research aimed to assess the effect of mineral nitrogen associated to different plant densities on yield, yield components and oil and protein concentrations of soybean grains. Two experiments were conducted in the 2013/2014 and 2014/2015 growing seasons, with randomized complete block design, in a split plots scheme, with six replications. Four sowing densities (150, 300, 440 and 560 thousand viable seeds; ha-1) were allocated in the plots, and two nitrogen levels (0 and 45 kg N; ha-1, applied at V2, using ammonium sulfate) were allocated in the subplots. There was no interaction between soybean plant density and the application of mineral nitrogen on yield, yield components and oil and protein concentrations in soybean grains. Higher plant population reduced the number of pods per plant and the contribution of branch sinks to the grain yield, but the effects on yield differed among the growing seasons. The mineral nitrogen fertilization did not increase yield and protein and oil concentrations in the grains, thus it was unnecessary.

Microwave-assisted solvent extraction and analysis of shikimic acid from plant tissues.

A better method for determination of shikimate in plant tissues is needed to monitor exposure of plants to the herbicide glyphosate [N-(phosphonomethyl)glycine] and to screen the plant kingdom for high levels of this valuable phytochemical precursor to the pharmaceutical oseltamivir. A simple, rapid, and efficient method using microwave-assisted extraction (MWAE) with water as the extraction solvent was developed for the determination of shikimic acid in plant tissues. High performance liquid chromatography was used for the separation of shikimic acid, and chromatographic data were acquired using photodiode array detection. This MWAE technique was successful in recovering shikimic acid from a series of fortified plant tissues at more than 90% efficiency with an interference-free chromatogram. This allowed the use of lower amounts of reagents and organic solvents, reducing the use of toxic and/or hazardous chemicals, as compared to currently used methodologies. The method was used to determine the level of endogenous shikimic acid in several species of Brachiaria and sugarcane (Saccharum officinarum) and on B. decumbens and soybean (Glycine max) after treatment with glyphosate. The method was sensitive, rapid and reliable in all cases.

Physicochemical and antioxidant properties of the pequi (Caryocar brasiliense Camb.) almond oil obtained by handmade and cold-pressed processes.

Abstract: The aim of this study is to characterize physical and chemically and determine the antioxidant capacity of pequi almond oils (PAO) extracted by handmade and by cold-pressing. Both oils showed good quality by acid, peroxide and thiobarbituric acid values. The fatty acid (FA) profile showed a significant presence of monounsaturated FA, mainly oleic acid (53.48 to 55.41%); saturated FA, such as palmitic acid (33.30 to 35.89 %); and polyunsaturated FA (PUFA), such as linoleic acid (5.85 to 7.23%). The total phenolic (TP) and carotenoid content ranged in concentration from 87.56 to 392.00 mg GAE/100 g and 36.03 to 262.40 mg/100 g, respectively. The tocopherol and phytosterol results indicated the predominant presence of α-tocopherol (52 to 67%) and stigmasterol (63 to 68 %). The antioxidant capacity of PAO as measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH?) method oscillated from 58.48 mg/mL to 76.46 mg/mL (IC50), from 10.61 to 40.46 µmol TE/g by the 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS?+) method, and from 113.93 to 280.85 µmol TE/100 g and 164.49 to 277.86 µmol TE/100 g, by the lipophilic and hydrophilic oxygen radical absorbance capacity (ORAC) methods, respectively. The oils presented a good oxidative and thermal stability by Rancimat method (IP of 7.33 a 15.91 h) and curves thermogravimetric and differential scanning calorimetry (To 337-363 °C and 159-184 °C, respectively). The results confirmed the presence of compounds that conferred antioxidant capacity and oxidative and thermal resistance for PAO made by handmade or cold-pressing, indicating that these oils can potentially be used for food and non-food applications.

Environmental effect on sunflower oil quality.

Sunflower is one of the most important oilseed crops and produces a high-quality edible oil. Balance of fatty acids in standard sunflower oil shows preponderance of linoleic rather than oleic acid, and conditions during seed development, such as temperature, changes the oleic/linoleic ratio of the oil. This work aimed to evaluate the environmental effect on fatty acid profile in a group of standard and high oleic varieties and hybrids. Seeds were produced during regular season crop and during off-season crop featuring different temperatures from anthesis to maturity. Fatty acid composition was determined by gas chromatography. Levels of oleic acid, in standard oil genotypes, raised as the crop developed in warmer environment while levels of linoleic acid decreased, and the opposite was observed when the crop was grown under lower temperature. High oleic genotypes were less sensitive to environment switching and showed lower variation on fatty acid composition.