Production and evaluation of potassium fertilizers from silicate rock

Rising price and limited geographical availability of traditional sources of potassium (K) fertilizers have stimulated a search for alternative K sources in different parts of the world. We evaluated mineral transformations and agronomic properties of an alternative source of K produced through thermal and chemical treatment of the verdete rock (VR). Chemical and mineralogical characteristics were evaluated before and after each treatment. Four K sources (verdete rock, KCl, acidified verdete, and calcinated verdete) were applied to a Typic Hapludox at different rates. Eucalyptus and sequentially cropped maize and grass were grown in the treated soils. Verdete rock, which contained glauconite and microcline as K crystalline minerals, had very low solubility in water and in citric acid. Thermal and chemical treatments increased the concentration of water soluble K and citric acid soluble K. These treatments also caused crystalline K minerals to collapse and form sylvite and arcanite. Untreated verdete rock was not suitable as a K source for maize (Zea mays L.) and eucalyptus (Eucaliptus urograndis I144). Thermal and chemical treatments increased agronomic performance of VR to be similar to KCl. When K was applied as K‐calcined verdete, 82% of the total K was recovered in maize and grass cultivations. Less K was recovered in plant following addition of K‐acidified verdete and KCl (72% and 77%, respectively). Potassium recoveries by eucalyptus were about 52, 53, and 60% of the amount applied of calcined verdete, acidified verdete, and KCl, respectively. Both calcination and thermal treatment increased the K uptake and dry matter production for all plant species tested to be similar to KCl suggesting that this silicate rock could be beneficiated to be an effective K fertilizer.     

Postpartum follicular development in Brahman cows under two stocking rates

The aim was to study postpartum follicular population dynamics in Brahman cows in the Mexican humid tropics and under different stocking rates. Lactating adult cows (n = 104) grazed native grammas (Paspalum spp., Axonopus spp.) under two stocking rates: 2.8 (high) or 1.7 (low) cows/ha. Follicle numbers and their size (millimetres) were measured by ovarian ultrasound scanning. Animals detected in oestrus and inseminated were taken out of the study. Both stocking rates produced similar (P < 0.05) body condition scores (BCS) and follicular dynamics. The percent of follicles, averaged over stocking rates, of <4 mm diminished and those of 5–8 mm increased with time, whilst those of >9 mm remained constant; respective values for the previously mentioned sizes were 60 days postpartum (n = 101), 49%, 56% and 5%; 120 days (n = 70), 28%, 66% and 6%; and 180 days (n = 15), 9%, 79% and 12%. There was a positive correlation between BCS and follicle number for size <4 mm (r = 0.73, P < 0.01), whilst for size 5–8 mm, this was negative (r = −0.51, P < 0.05), for follicles >9 mm, no difference was found (r = −0.08, P > 0.05). It was concluded that stocking rate did not affect follicular population dynamics of Brahman cows, but BCS dictated the number and categories of follicles present regardless of the stocking rate utilised.     

Fossil evidence for evolution of the shape and color of penguin feathers

Penguin feathers are highly modified in form and function, but there have been no fossils to inform their evolution. A giant penguin with feathers was recovered from the late Eocene (~36 million years ago) of Peru. The fossil reveals that key feathering features, including undifferentiated primary wing feathers and broad body contour feather shafts, evolved early in the penguin lineage. Analyses of fossilized color-imparting melanosomes reveal that their dimensions were similar to those of non-penguin avian taxa and that the feathering may have been predominantly gray and reddish-brown. In contrast, the dark black-brown color of extant penguin feathers is generated by large, ellipsoidal melanosomes previously unknown for birds. The nanostructure of penguin feathers was thus modified after earlier macrostructural modifications of feather shape linked to aquatic flight.     

Forest proximity rather than local forest cover affects bee diversity and coffee pollination services

Context

As agricultural demands for land continues to expand, strategies are urgently needed to balance agricultural production with biodiversity conservation and ecosystem service provision in agricultural landscapes.

Objectives

We used a factorial landscape design to assess the relative contributions of forest proximity and local forest cover to bee diversity and the provision of coffee pollination services.

Methods

We quantified bee diversity and fruit set in 24 sun-grown coffee fields in Southeast Region of Brazil that were selected following a factorial sampling design to test the independent effects of local forest cover (in a radius of 400 m) and proximity to forest fragments. To assess the impact of landscape simplification, we also evaluated local coffee cover.

Results

Bee richness and abundance were higher in the proximity of forest fragments, but only bee abundance decreased when the coffee cover dominated the surrounding landscapes. Coffee fruit set was 16% higher overall with bee visitations compared with bee exclusion and increased to 20% when coffee bushes were near forest fragments, and the coffee cover was low. Surprisingly, local forest cover did not affect the bee community or coffee fruit set.

Conclusion

Our results provide clear evidence that the proximity of coffee crops to forest fragments can affect the abundance and richness of bees visiting the coffee flowers and thereby facilitate the provision of pollination services. The positive association between forest proximity and fruit set reinforces the importance of natural vegetation in enhancing bee diversity and, therefore, in the provision of pollination services. The negative effect of coffee cover on fruit set at the local scale suggests that the service demand can surpass the capacity of pollinators to provide it. These effects were independent of the local forest cover, although all studied landscapes had more than 20% remaining forest cover (within a 2 km radius), which is considered the extinction threshold for Atlantic Forest species. Interspersion of forest fragments and coffee plantations in regions with more than 20% of forest cover left could thus be a useful landscape management target for facilitating pollinator flows to coffee crops and thus for increasing coffee yields.

     

Studies of various elements of nutritional and toxicological interest associated with different molecular weight fractions in Brazil nuts

On-line hyphenation of size exclusion chromatography (SEC), UV, and inductively coupled plasma mass spectrometry (ICP-MS) was used to study the molecular weight distribution patterns of several elements in Brazil nuts (Bertholletia excelsa). This technique was used for the elemental speciation of different elements of nutritional and toxicological interests such as Mg, Fe, Co, Mo, Ag, Hg, and Pb. Elemental fractionation in Brazil nuts was studied using a Superdex peptide column with resolving capacity in the range of 14 to 0.18 kDa. Three different mobile phases, Tris buffer solution (pH 8.0), phosphate buffer (pH 7.5), and CAPS buffer solution (pH 10.0), were tried for the SEC fractionation. Size exclusion fractionation of all the extracted solutions was performed using a 50 mmol L(-)(1) Tris buffer (pH 8) as the mobile phase at a flow rate of 0.6 mL min(-)(1). Three different extractions, 0.05 mol L(-)(1) NaOH, 0.05 mol L(-)(1) HCl, and hot water at 60 degrees C, were performed, and the association of elements with various molecular weight fractions was evaluated. Total elemental concentrations in the extracted samples were determined and compared with the values obtained after total digestion to calculate the recovery values. Generally, high extraction efficiency was obtained with the NaOH solution as compared with HCl and hot water except in the case of magnesium, for which HCl was found to be a good extractant. Chromatographic elution profiles for these extractions were quite distinct from each other in most cases. Most of the elemental species were found to be associated with high molecular weight fractions. To study the differences obtained during the sample-processing step, the results obtained for nuts with shell were treated differently from those obtained for nuts purchased without shell and were compared.     

Processing of rice husk autohydrolysis liquors for obtaining food ingredients

Rice husks are of a lignocellulosic nature, with a hemicellulose fraction made up of substituted arabinoxylan. Rice husks were treated with hot, compressed water (autohydrolysis reaction) under optimized conditions to cause the hydrolytic degradation of arabinoxylan. The reaction products contained volatile components and nonvolatile components (NVC), which were made up of hemicellulose-derived products (substituted oligosaccharides and monosaccharides) and other nonvolatile solutes (ONVS). To decrease the content of ONVS, concentrated autohydrolysis liquors were first subjected to ethyl acetate extraction and then subjected to various alternative treatments (solvent precipitation, freeze-drying solvent extraction, or ion exchange). The resulting liquors were assayed for composition and yield determination. Material balances are presented for the several processes considered. The best results in terms of purification were obtained with sequential stages of ethyl acetate extraction and ion exchange, which led to concentrates with hemicellulose-derived compounds (sugars and substituted sugar oligomers) accounting for 92 wt % of the NVCs.     

Reproductive cycle of the sea cucumber <Emphasis Type="Italic">Holothuria floridana</Emphasis> in the littorals of Campeche,Mexico

The reproduction of Holothuria floridana in Campeche bay, southern Gulf of Mexico, was investigated over a period of 12 months by macroscopic and histological examination of the gonad and gametogenesis. A total of 1938 specimens were collected. Their body gutted weight and body gutted length ranged from 15 to 225 g and 5 to 21 cm, respectively. Percentage of the gonad weight to the gutted body weight (gonad index, GI) increased steadily from December to April, rapidly declined in May, and remained low during the following months. GI displayed a negative correlation with temperature of the habitat and no correlation with salinity. The gonad maturity scale with five stages was developed from macroscopic and microscopic observations; I, recovery; II, growing; III, early mature; IV, mature and V, spent. Stages III to V were observed all around the year, suggesting that this species displays continuous reproduction with two peaks of spawning events; from March to April and in September. The presence of viscera regurgitated individuals caused high variability in GI. The sex-ratio varied from 1:1 (December 2013 to June 2014), to 1.37:1 (November 2013); we suggest that this may be the consequence of unintentional selective fishing. The body length and body weight at the first maturity were calculated to be 13.4 cm and 87.0 g, respectively. For resource management it will be necessary to address some reference points like harvest season and avoidance of catches shorter than length at first maturity.     

Cobalt and molybdenum stimulate compounds of primary metabolism,nitrogen forms,and photosynthetic pigments in peanut plants (Arachis hypogaea L.)

Abstract

The objective of this study was to evaluate the effects of cobalt (Co) and molybdenum (Mo) doses in the treatment of seeds on the biosynthesis of nitrogen compounds, photosynthetic pigments, sugars, and production of peanut plants. The doses of Co and Mo used were 0, 2, 3, and 4?mL kg^?1 seed, which were applied immediately before sowing. Seeds treated with Co and Mo at a dose of 4?mL kg^?1 yielded peanut plants with higher concentrations of photosynthetic pigments, carotenoids, and sucrose in leaves. Application of Co and Mo doses also increased biological nitrogen fixation by increasing the concentration of allantoic acid, nitrate, ammonia, and amino acids in leaves. The concentration of total amino acids corresponded to most of the nitrogen compounds (on average 50%), followed by the concentrations of nitrate (35%), ammonia (11%), allantoic acid (7%), and allantoin (0.2%). Application of 4?mL kg^?1 increased the production of total amino acids compared with the control treatment. Pod yield was not affected by the Co and Mo doses; however, treatment of peanut seeds with 4?mL kg^?1 was the most viable alternative for increased production of primary metabolism compounds, nitrogen forms, and photosynthetic pigments in peanut plants. This study provides important information regarding the role of Co and Mo in the biological nitrogen fixation of peanut plants. Future experiments should be conducted using a dose of 4?mL kg^?1 with different genotypes to verify the potential for increasing peanut yield.     

Effects of Leucaena biomass application in conjunction with fertilizers on cassava and taro yields in the Philippines

With the soaring cost and scarcity at times of inorganic fertilizers in the country, there is a need to find alternatives to inorganic fertilizers by making use of indigenous materials such as leaves of leguminous plants, mudpress, and so enhance growth and development of crops. Application of ‘ipil-ipil’ (Leucaena leucocephala) green manure supplemented with inorganic P and K caused vigorous growth of cassava (Manihot esculenta). Application of ipil-ipil biomass at the rate of 7.23 t ha−1 resulted in high yield and better values of yield components of cassava. However, due to high expenses incurred in hauling, transport and cost of the green manure materials, their use is likely to be more economical and feasible only if ipil-ipil is readily available in the farm. With taro (Colocasia esculenta), combined application of ipil-ipil green manure and inorganic P and K promoted vigorous stand and higher yield of the crop. Significantly larger corms were formed resulting in higher total corm yields and marketability than the control (untreated) and those treated only with 60–39.6–74.7 kg ha−1 N, P, and K from inorganic fertilizer. Increasing the rate of inorganic N applied to plants (90–36.9–74.7 kg ha−1 N, P, K) during a third cropping, gave comparable yield to treatment involving 7.23 t ha−1 ipil-ipil supplemented with inorganic P and K. Despite the relatively higher gross income obtained from organic and inorganic treatment combinations, slightly lower net income was obtained compared with inorganic fertilizer-applied plants due to higher production expenses incurred with the former treatments. This revised version was published online in June 2006 with corrections to the Cover Date.     

Association of gastric lymphofollicular hyperplasia with Helicobacter‐like organisms in dogs

BackgroundThe relationships among gastric lymphoid follicular hyperplasia (GLFH), Helicobacter‐like organisms (HLOs), and clinical signs have not been established in dogs.ObjectivesTo evaluate the epidemiologic, clinical, endoscopic, and histopathologic findings associated with GLFH in dogs, and determine the association of GLFH with HLOs and the French Bulldog (FB) breed.AnimalsTwo hundred eighty‐eight dogs that underwent gastroscopy between 2013 and 2016.MethodsRetrospective, cross‐sectional study. Gastric biopsy samples were reviewed and scored for inflammation and HLOs. Dogs were divided into 3 groups: group 1 (63 FBs), group 2 (45 non‐FB brachycephalic dogs), and group 3 (180 nonbrachycephalic dogs). Variables were evaluated for their association with GLFH.ResultsUnivariate analysis determined that intact males, young age, vomiting, gastroscopic findings (discoloration, hemorrhage, and ulcers), and histopathologic findings (gastric lamina propria lymphocytic infiltration and HLO score) were associated with GLFH (P ≤ .03). In the multivariate analysis, GLFH was associated with the HLO score (odds ratio [OR] > 5 for HLO scores 1‐2 and >15 for HLO score of 3; P < .001), with vomiting (OR > 4; P = .01) but not with FB breed (P = .76) and age (P = .1). The HLO score was associated with younger age (P < .001).Conclusion and Clinical ImportanceThe HLO score was associated with a high GLFH score. Vomiting was associated with GLFH. Helicobacter‐like organisms are highly prevalent in young dogs and GLFH is indirectly associated with this factor. Clinical relevance of the identification of GLFH and HLO remains to be determined.