Azolla spp. is a water fern that hosts Anabaena azolla, an N-fixing cyanobacterium, in its dorsal leaf cavities. Azolla occurs naturally in freshwater bodies in warm-temperate and tropical regions, ...and they have commonly been grown in rice paddies as a living fertilizer, providing N to the rice crop. We evaluated the potential use of Azolla harvested from freshwater bodies and applied as a biofertilizer to dryland vegetable crops. Two-thirds of the greenhouse gas emissions from crop production is attributed to N fertilizer, including fossil fuels used in fertilizer production and transportation. Azolla grown in on-farm ponds could remove CO2 from the atmosphere and minimize the use of fossil fuels in fertilizer production and transport. A 140-d laboratory incubation was used to compare the N mineralization of Azolla biofertilizer with compost and cyanobacterial biofertilizer treatments. Azolla treatments had the greatest N availability at the end of the incubation (73.0%), with compost demonstrating the least N availability (15.5%), and the cyanobacterial biofertilizers moderate in N release (31.6%). A greenhouse study evaluated the N uptake and yield of kale (Brassica oleracea) receiving Azolla biofertilizer compared to urea and organic fertilizers. The nitrogen uptake by kale followed the same pattern as in the incubation study, with the Azolla treatments highest among the organic fertilizers, and urea the greatest overall. Compost yielded better than the control but was the lowest yielding among the fertilizer treatments. Finally, we compared the agronomic effect of Azolla biofertilizer with urea and manure applied at the same N rates to spinach (Amaranthus cruentus) and radish (Raphanus sativus) crops grown in the field on alluvial and peat soils. Fertilizer treatments affected the spinach yield at both locations but did not affect the radish yield. The manure treatment resulted in the highest spinach yields (18–27 t ha−1), and the Azolla treatment applied at the same N rate as the manure yielded the same as the manure treatment on the peat soil and had the highest leaf and branch numbers. Azolla shows promise as a biofertilizer for dryland vegetable crops; however, an economic feasibility analysis is needed prior to encouraging the widespread adoption of on-farm Azolla production and use.
ABSTRACT Amaranth (Amaranthus cruentus L.) is a food high in protein and lysine content, and has a well-balanced amino acid composition. In addition, it has shown to be efficient in lowering egg ...cholesterol. The objective of this study was to evaluate the effect of different inclusion levels of Amaranthus cruentus L. in the diet of laying hens, on egg cholesterol content and production parameters. 200 laying hens of 30 weeks of age were fed on diets that included 0, 15, 30 and 45% (dry matter basis) of A. cruentus. For 2 months, weekly feed intake per hen, egg production per week, egg mass and feed conversion ratio were evaluated. 480 eggs were analyzed to determine cholesterol content by high performance liquid chromatography. The results were analyzed by analysis of variance for a randomized block design. The inclusion of 15% of A. cruentus seeds in the diet decreased egg yolk cholesterol content without significantly affecting the main production parameters.
Description du sujet. La fertilisation microdose a été développée pour la production des légumes feuilles africains (LFA) afin de réduire les doses élevées de fertilisants souvent appliquées pour ...leur production en Afrique de l'Ouest. Objectifs. Cette étude vise a (i) évaluer la réponse de trois légumes-feuilles africains (LFA, Amaranthus cruentus L., Solanum macrocarpon L. et Ocimum gratissimum L.) a l'apport combiné du fumier de bovins et d'urée en microdose puis (ii) évaluer leur facteur partiel de productivité de l'azote. Méthode. Des expérimentations en station ont été conduites durant trois saisons culturales (2015 a 2017) au Nord Bénin. Six doses d'urée-N : 0, 10, 20, 30, 40 et 60 kg.ha-1 combinées a 5 l·ha-1 de fumier de bovins (M5N0, M5N10, M5N20, M5N30, M5N40 et M5N60, respectivement) et l'application exclusive de 40 (M0N40) et 80 kg d'uree-N·ha-1 (M0N80) comme témoin et deux temps d'application de l'urée (T1 = 0 et T2 = 14 jours apres le repiquage) ont été testés dans un dispositif en blocs aléatoires complets avec quatre répétitions. Resultats. Le traitement M5N60 a enregistré le rendement en légume frais de A. cruentus le plus élevé, avec une amélioration de 90 et 151 % par rapport a M5N0 et les deux traitements M0N40 et M0N80, respectivement, tandis que le traitement M5N40 a amélioré le rendement frais de S. macrocarpon de 23 % par rapport a M5N0. Cependant, aucune différence significative n'a été observée entre les différentes doses d'urée-N appliquées sous O. gratissimum. De plus, la période d'application de l'engrais n'a affecté ni le rendement frais ni le facteur partiel de productivité d'aucune des especes de légume étudiées. Conclusions. Le microdosage combiné de fumier et d'urée constitue une pratique prometteuse de gestion des nutriments en Afrique de l'Ouest pour la production des LFA car elle permet d'améliorer les rendements tout en économisant les engrais pour les petits producteurs de légumes.
Introduction. The production potential of grain amaranth has recently been demonstrated in northeastern Patagonia, Argentina. This crop under irrigation and in a temperate semi-arid climate showed an ...adequate development of the plants in their different phenological stages with high economic performance. Objectives. This study explored the response of Amaranthus cruentus cv Mexicano to different irrigation frequencies in the lower valley of Río Negro river, Patagonia, Argentina. Method. The experimental design was of three blocks with randomized treatments (subplots), each one corresponding to a different irrigation frequency. The first six irrigations were performed every 7 days for all the treatments, to ensure the establishment of the crop. Then the following treatments were applied: irrigation every 7 days (FI), every 14 days (FII), and every 21 days (FIII). The following biometric variables and their components were measured: height of plant, number of leaves, biomass and economic yield. Results. The results suggest that the optimum irrigation frequency was FII (14 days), resulting in an adequate plant stand at panicle initiation and allows a proper development of plant with optimal biological and economical yields and the highest efficiency of water use (4.02 kg·m-3). Conclusions. The contributions of this study demonstrated the production potential of A. cruentus crop in the lower valley of the Río Negro river under irrigation, representing the southernmost study on irrigation frequency made for this grain crop in the world. A management of irrigation water of 7 days for the establishment of the crop and then with a frequency of 14 days showed the highest yield and the best water use efficiency.
Fréquence d'irrigation de l'amarante dans le nord-est de la Patagonie, Argentine Introduction. Récemment, il a été démontré le potentiel de la culture d’amarante en Patagonie du Nord, en Argentine. Cette culture sous irrigation et en climat tempéré semi-aride a montré un développement adéquat des plantes dans leurs différents stades phénologiques avec des performances économiques élevées Objectifs. Cette étude a exploré la réponse de Amaranthus cruentus cv Mexicano à une fréquence différente d’irrigation dans la basse vallée de la rivière Río Negro, en Patagonie, en Argentine. Méthode. Un modèle expérimental de trois blocs avec des traitements randomisés (sous-parcelles), chacun correspondant à différentes fréquences d'irrigation, a été appliqué. Les six premières irrigations pour tous les traitements effectués tous les 7 jours eurent pour but d'assurer l'implantation de la culture. Ensuite, la FI a maintenu cette fréquence, la FII tous les 14 jours et FIII tous les 21 jours. Les variables biométriques suivantes et leurs composants ont été mésurés : hauteur de la plante, nombre de feuilles, biomasse et rendement économique. Résultats. Les résultats suggèrent que FII est la fréquence d'irrigation optimale. Cette fréquence d'irrigation génère un peuplement adéquat à l'initiation des panicules et permet un développement correct de la plante avec des rendements biologiques et économiques optimaux et la meilleure efficacité d'utilisation de l'eau (4,02 kg·m-3). Conclusions. Cette étude a démontré le potentiel de culture de A. cruentus dans la basse vallée de la rivière Río Negro, représentant l'étude de la densité d’installation réalisée pour cette culture de céréales la plus australe au monde. Une gestion de l'eau d'irrigation de 7 jours pour la mise en place de la culture puis avec une fréquence de 14 jours a montré le rendement le plus élevé et la meilleure efficacité d'utilisation de l'eau.
The genus Amaranthus comprises about 70 species, of which 40 are native to the American continent and
the rest of Australia, Africa, Asia and Europe. A. caudatus L., A. hypochondriacus L. and A. ...cruentus L. are
the species that in recent years have created a strong interest as agricultural crops in many regions of the
world due to the high nutritional value of their seeds and leaves. Amaranth, considered one of the most
nutritious pseudocereals, mainly used for human consumption in several ways; highlighting among them
the production of solid sweets with their seeds or drinks based on flour, as vegetables, as fodder for
livestock and for obtaining oils and cosmetic products. In spite of being considered by FAO as the crop
with the greatest potential for technical development for the regions and communities of America due to
the nutritional characteristics of the whole plant as well as the attribute of its excellent capacity to resist
soils and dry climates, It presents a very slow production curve, mainly at low yields, hence, the objective
of this review is to perform an analysis of the multiple forms, in addition to consumption, in which amaranth
can be used, and with this, in some way, motivate farmers to continue cultivating it.
El género Amaranthus comprende alrededor de 70 especies, de las cuales 40 son nativas del continente
Americano y el resto de Australia, África, Asia y Europa. A. caudatus L., A. hypochondriacus L. y A.
cruentus L. son las especies que en años recientes han creado un fuerte interés como cultivos agrícolas
en muchas regiones del mundo por el alto valor nutrimental de sus semillas y hojas. El amaranto,
considerado uno de los pseudocereales más nutritivos, es principalmente usado para el consumo humano
de varias maneras; destacando entre ellas la elaboración de dulces sólidos con sus semillas o bebidas a
base de harina, como verdura, como forraje para el ganado y para la obtención de aceites y productos
cosméticos. A pesar de ser considerado por la FAO como el cultivo con mayor potencial técnico de
desarrollo para las regiones andinas y costeras de América debido a las características nutritivas de la
planta entera así como la cualidad de su excelente capacidad de resistencia a suelos y climas secos,
presenta una curva de producción muy lenta debido principalmente a los bajos rendimientos, de aquí que
el objetivo de la presente revisión sea realizar un análisis de las múltiples formas, además del consumo, en que puede usarse el amaranto, y con esto, de alguna manera, motivar a los agricultores para que lo
sigan cultivando.
This article explores the response of three genotypes of Amaranthus to different sowing date and to different doses of nitrogen (N) fertilization. The experimental design was a randomized complete ...block design with three replicates for cultivars, planting date and fertilization per treatment. Mexicano sown in early December had the best yield (5285 kg ha
-1
) with highly significant differences (p < 0.001) respect to Dorado and Antorcha. To assess the N fertilization Mexicano cultivar was sown at the end of spring (1 December). Morphophysiological variables increased as the N fertilization dose was raised. Higher doses of N fertilizer resulted in greater economic yields this was mainly due to the increase in grain number rather than that of a 1000 grain weight. The results of this investigation suggest that sowing Amaranthus cruentus cv Mexicano on 1 December with 150 kg N ha
−1
favors its general development and allows to obtain high economic and biological yields with an appropriate protein content.
Diet has been established as a major source of exposure to Polycyclic aromatic hydrocarbon for humans (PAHs) especially nonsmokers. Therefore their presence in plants constitute a major health ...concern. This research aims at determining the concentration and profile of sixteen US-EPA priority PAHs in tropical edible vegetables (Corchorus olitorius (Ewedu), Celosia argentea (Soko), Amaranthus cruentus L (Grain amaranthus/Tete), Telfairia occidentale (Ugwu), Basella alba (Amunu tutu/White Spinash), Lactuca Sativa (Lettuce), Allium ascalonicum (Spring Onions/Alubasa elewe), Talinum Triangulare (Water leaf)), grown on potted contaminated soils. Vegetable grown on potted contaminated soils and contaminated soils were extracted using n-hexane/acetone mixture in ultrasonic bath. Extracts were purified using C
18
solid-phase extraction cartridge (5 mL). Resultant extracts were quantified for PAHs on an Agilent 6890 Gas chromatography/mass spectrometer (GC/MS). Total PAH concentration in contaminated soils and plants grown on them were 200 - 250,000 ng g
−1
and 100-5,000 ng g
−1
, respectively. Two and three ringed PAHs which are the less toxic were the dominant PAH type present in most of the plant parts. Telfairia occidentale (Ugwu) consistently grew on all the soils samples which suggest it possess some potential for phyto remediation. Lactuca sativa (Lettuce) had few growth only the least contaminated soils. Its ability to grow on soils with low contamination makes it a potential bio indicators for polluted soils.
Trials are currently being conducted in South Africa to establish Amaranthus cruentus as a new pseudocereal crop. During recent surveys, Fusarium species were associated with weevil damage in A. ...cruentus fields. Preliminary studies showed that some of these Fusarium species grouped into two distinct clades within the F. fujikuroi species complex. The aim of this study was to characterize these isolates based on the morphology and phylogeny of the translation elongation factor 1α (TEF1α) gene region, ß-tubulin 2 (ßT) gene region and RNA polymerase II subunit (RPB2), and to determine if these isolates are pathogenic to A. cruentus. Phylogenetic and morphological studies showed that these two clades represent two novel species described here as F. casha and F. curculicola. Both species were shown to have the potential to be pathogenic to A. cruentus during routine greenhouse inoculation tests. While isolations indicate a possible association between these two species and weevils, further research is needed to understand this association and the role of weevils in disease development involving F. casha and F. curculicola in A. cruentus.
Perennial species with the C-4 pathway hold promise for biomass-based energy sources. We have explored the extent that CO2 uptake of such species may be limited by light in a temperate climate. One ...energetic cost of the C-4 pathway is the leakiness (phi) of bundle sheath tissues, whereby a variable proportion of the CO2, concentrated in bundle sheath cells, retrodiffuses back to the mesophyll. In this study, we scale phi from leaf to canopy level of a Miscanthus crop (Miscanthus x giganteus hybrid) under field conditions and model the likely limitations to CO2 fixation. At the leaf level, measurements of photosynthesis coupled to online carbon isotope discrimination showed that leaves within a 3.3-m canopy (leaf area index = 8.3) show a progressive increase in both carbon isotope discrimination and phi as light decreases. A similar increase was observed at the ecosystem scale when we used eddy covariance net ecosystem CO2 fluxes, together with isotopic profiles, to partition photosynthetic and respiratory isotopic flux densities (isofluxes) and derive canopy carbon isotope discrimination as an integrated proxy for phi at the canopy level. Modeled values of canopy CO2 fixation using leaf-level measurements of phi suggest that around 32% of potential photosynthetic carbon gain is lost due to light limitation, whereas using phi determined independently from isofluxes at the canopy level the reduction in canopy CO2 uptake is estimated at 14%. Based on these results, we identify phi as an important limitation to CO2 uptake of crops with the C-4 pathway.
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