Efecto del pH sobre la concentración de nutrientes en cacao (Theobroma cacao L.) en la Amazonia Colombiana / Effect of pH on the nutrient concentration in cocoa (Theobroma cacao L.) in the Colombian Amazon

RESUMEN La acidez del suelo limita la disponibilidad, la absorción y la concentración de nutrientes y el rendimiento del cultivo de cacao. El objetivo fue evaluar el efecto del pH del suelo sobre la concentración de nutrientes en hoja, cáscara y grano, para cuatro clones de cacao autocompatibles (ICS-1, CCN-51) y autoincompatibles (ICS-39, TSH-565), en el departamento del Caquetá. El diseño experimental consistió en un arreglo factorial con cuatro clones (factor A), cuatro niveles de pH y fertilidad (factor B) y cuatro repeticiones. Los resultados indican diferencias en la concentración de nutrientes por efecto del clon y tratamiento, siendo la acumulación de N, P y Mg en grano>hoja>cáscara, K en cáscara>hoja>grano, Ca, Fe, Mn, Zn y B en hoja>cáscara>grano, S en cáscara>hoja>grano y Cu en grano>cáscara>hoja. La concentración de P, Mg y S fue mayor y, a su vez, menor Mn, cuando aumentó el pH. El orden de extracción nutrimental en grano fue N>K>P>Mg>S>Ca>Fe>Mn>Zn>Cu>B. Con relación a los clones, CCN-51 presentó habilidad para la toma de nutrientes y alcanzar mayores producciones, incluso, en suelos con pH ≥ 5,5, lo que sugiere efecto de las condiciones edafoclimáticas y, por lo tanto, la necesidad de evaluar los clones para cada zona de cultivo.

ABSTRACT The soil acidity limits availability, absorption and concentration of nutrients and yield of the cocoa crop. The objective was to evaluate the effect of soil pH on the concentration of macro and micronutrients in leaf, husk and grain for four cocoa clones, self-compatible (ICS-1, CCN-51) and self-incompatible (ICS-39, TSH-565) in the department of Caquetá. The experimental design consisted in a factorial arrangement with four clones (factor A), four pH and fertility levels (factor B) and four repetitions. The results indicate differences in the concentration of nutrients due to the effect of the clone and the treatment, being the accumulation of N, P and Mg in grain>leaf>husk, K in husk>leaf>grain, Ca, Fe, Mn, Zn y B in leaf>husk>grain, S in husk>leaf>grain and Cu in grain>husk>leaf. The concentration of P, Mg and S was higher, and in turn Mn lower, when the pH increased. The order of nutrient extraction in grain was N>K>P>Mg>S>Ca>Fe>Mn>Zn>Cu>B. Regarding clones, CCN-51 showed ability to take nutrients and reach higher productions, even in soils with pH ≥ 5.5, suggesting effect of edaphoclimatic conditions, and therefore, the need to evaluate the clones for each growing area.

Corn (Zea mays L.) growth, nutrient uptake and soil fertility improvement of strongly acidic soil applied with biochar and animal manure

The effects of biochar and animal manure application on soil chemical properties, nutrient uptake, growth, andbiomass production of corn grown in strongly acidic soil were assessed in a pot experiment. The experimentwas laid out in randomized complete block design with the following treatments: (1) control; (2) 15 t chickenmanure (CM) ha−1; (3) 30 t CM ha−1; (4) 15 t carabao dung (CD) ha−1; (5) 30 t CD ha−1; (6) 15 t chickenmanure biochar (CMB) ha−1; (7) 30 t CMB ha−1; (8) 15 t carabao dung biochar (CDB) ha−1; and (9) 30 tCDB ha−1. Application of 30 t CM ha−1 significantly increased soil pH by 1.03-unit, total organic carbon,total N, and exchangeable K by 138%, 300%, and 955%, respectively, and a 108-fold increase in P, over thecontrol treatment. Similarly, the addition of CM at 15 t ha−1 significantly increased all soil chemical parametersgathered. Moreover, the addition of 15 t CM ha−1 increased plant height, shoot, and total biomass by 62%,161%, and 148% over the control treatment. Meanwhile, tissue N uptake of corn increased by 147% and 124%with the CM application at the rate of 15 t ha−1 and 30 t ha−1. Among organic materials evaluated, CM had themost superior influence on soil chemical properties, growth, biomass production, and plant nutrition.

Screening of Beneficial Microorganisms to Improve Soybean Growth and Yield

Abstract The objective of this research was to identify the best microorganisms, alone or in mixture for total biomass gain (root + shoot), positive change in gas exchange, nutrient uptake (root, shoot and grain) and yield and yield components in the soybean crop. Trial under greenhouse conditions had the experimental design in a completely randomized scheme with 26 treatments and four replicates. The treatments consisted of the rhizobacteria BRM 32109, BRM 32110 and 1301 (Bacillus sp.), BRM 32111 and BRM 32112 (Pseudomonas sp.), BRM 32113 (Burkholderia sp.), BRM 32114 (Serratia sp.), Ab-V5 (Azospirillum brasilense) and 1381 (Azospirillum sp.), and the fungus Trichoderma asperellum (a mix of the isolates UFRA.T06, UFRA.T09, UFRA.T12 and UFRA.T52). Besides, the same isolates were combined in pairs, completing 16 combinations. Control treatments received no microorganism. Microorganisms applied isolated or in combination, provided biomass gain, positive gas exchange, increases in nutrients uptake at the shoot and grain, and improved grain yield and its components than control plants. Stood out the combination Ab-V5 + T. asperellum pool, which provided a 25% improvement in grain yield.

Evaluation of micro-irrigation methods in pomegranate under semi-arid tropical climate of India

Aim: To evaluate different micro-irrigation systems against basin irrigation in terms of growth, yield, fruit quality, disease infestation and water use of pomegranate under semi-arid tropical climate of Central India. Methodology: A field experiment was conducted in newly planted pomegranate cv. Bhagwa orchard with four irrigation treatments, viz., drip (4 lph, 4 plant-1), microjet 180o (2 plant-1), microjet 360o (2 plant-1) and basin (double ring) irrigation replicated five times in a randomised block design (RBD) in heavy textured soil. Results: Basin irrigation is widely practiced method of irrigation which presently facilitate better soil moisture distribution, resulted in better root proliferation and higher leaf nutrient status (K 0.98%, Cu 105.4 ppm and Zn 35.9 ppm) followed by drip (N 2.12% and Mn 40.4 ppm) system of irrigation. Maximum fruit yield was obtained under basin and drip which was 376.7% and 242.8% higher than that obtained under microjet 180o irrigation system, respectively. Water use efficiency was highest in drip (0.526) than basin (0.499) system of irrigation. Disease incidence in the plants was less under drip while it was high under microjet system of irrigation. Interpretation: Experimental findings clearly indicate that the areas which had ample amount of irrigation, basin irrigation was the most efficient system in harnessing maximum yields, while drip irrigation resulted in higher water use efficiency under arid to semiarid tropical climate, micro-sprinkler irrigation system is not beneficial for pomegranate orchards.

Impacts of Elevated CO2 on Growth, Carbohydrate Assimilation and Nutrient Uptake of Elaeis guineesis Jacq Seedlings

Aims: This study was conducted to characterize the growth patterns of tenera oil palm seedlings performance (Deli AVROS) under elevated CO2, that is expected to increase in the future due to climate change. Study Design: The palms were exposed to three carbon enrichment treatments: (1) ambient CO2 (400 ppm); (2) twice ambient CO2 (800 ppm), and (3) thrice ambient CO2 (1200 ppm). Randomized complete block design (RCBD) with three replications was used during the experiment using Deli AVROS seedlings. Place and Duration of Study: Department of Biology, Faculty of Science Universiti Putra Malaysia from March 2017 to December 2017. Methodology: Carbon dioxide enrichment treatments started when seedlings reached three months old by exposing them to three levels of CO2, i.e., ambient CO2 (400 ppm), twice ambient CO2 (800 ppm) and thrice ambient CO2 (1,200 ppm). Growth, carbohydrate and macronutrients properties were measured at the end of the treatment period of 3 months. Results: It was found that CO2 had the greatest influence on the growth over the three months’ period of experiment. As the level of CO2 increased, from 400>800>1200 ppm, the plant height, number of frond per plant, basal diameter, leaf area per seedling, root biomass, total dry matter, net assimilation rate (NAR) and relative growth rate (RGR) was significant increased between the CO2 levels. The enhanced plant growth under elevated CO2 might be contributed by increased in production of total non-structural carbohydrate (TNC) of the palm under elevated CO2. The increased in TNC exposed to elevated CO2 was supported by increase in sucrose and starch content under these conditions. More sucrose was available than starch indicate that no feedback inhibition was occurred and the palm have enough sink strength to cope with elevated CO2. The macronutrients contents (N, P, K, Ca, Mg) also was found to be reduced under elevated CO2 treatments, indicated that growth enhancement under elevated have dilute the nutrient content in the palms. Conclusion: In conclusion, the growth of oil palm seedlings was enhanced with elevated CO2 at double and triple concentration than the ambient. It was found that the increase might be due to increase in production of total non-structural carbohydrate. The enhanced growth also increased the macronutrient demands under the elevated levels of CO2. This show in future the palm needs more fertilizers with enhanced levels of elevated CO2.

Regulation of T cell immunity by cellular metabolism / 医学前沿

T cells are an important adaptive immune response arm that mediates cell-mediated immunity. T cell metabolism plays a central role in T cell activation, proliferation, differentiation, and effector function. Specific metabolic programs are tightly controlled to mediate T cell immune responses, and alterations in T cell metabolism may result in many immunological disorders. In this review, we will summarize the main T cell metabolic pathways and the important factors participating in T cell metabolic programming during T cell homeostasis, differentiation, and function.

Yield, Quality and Nutrient Uptake as Influenced by Organic Manures and Inorganic Fertilizers in Finger Millet.

A field experiment was conducted to study the influence of organic manures and chemical fertilizers on yield, nutrient uptake by finger millet and soil fertility status at harvest during kharif 2013 at Agricultural Research Station, Perumallapalle, ANGRAU. The results revealed that significantly highest grain yield (37.21 q ha-1), protein content (8.82%), N uptake (84.80 kg ha-1), P uptake (12.04 kg ha-1), No. of tillers/plant (2.5), No. of fingers/ear head (13) were recorded in inorganic treated plot when compared with organic treated plot (35.08 q ha-1 of grain yield, 8.61% of protein content,75.29 kg ha-1 of N uptake, 11.58 kg ha-1 of P uptake, 2.2 tillers/plant, 11 fingers/earhead). Organic carbon content in soil was increased in organic plot (0.02% only) when compared with intial value. In both the treatments available N was reduced and available K was increased when compared with initial available N and K.

The Effect of Temperature on Nitrate and Phosphate Uptake from Synthetic Wastewater by Selected Bacteria Species.

Aim: The aim of this study was to ascertain the effect of temperature on nutrient uptake ability of four bacterial species. Methodology: A total of four bacterial species (Klebsiella sp., Pseudomonas sp., Lysinibacillus sp. and Staphylococcus sp.) were used for the study. The media used for the investigation was synthetic wastewater. Four different temperatures (25ºC, 30ºC, 35ºC and 40ºC) were used for the investigation. The study was carried out under shake flasks conditions. Immediate after inoculation with the respective test bacterial species and every 24 h for a 96 h incubation time, aliquot wastewater samples were removed from the flasks for the estimation of total phosphate, nitrate, pH and growth rate, using standard procedures. Results: The results revealed phosphate and nitrate removal ranges of 10.84 % to 55.55 % and 90.67 % to 97.27 %, respectively in the presence of the Klebsiella sp. In the presence of the Pseudomonas sp, Lysinibacillus sp. and Staphylococcus sp., phosphate removals ranges of 0.36 % to 46.98 %, 11.89 % to 50.80 % and 2.74 % to 51.21 % were observed, respectively. For nitrate concentrations, removal levels that ranged from 2.19 % to 92.95 %, 0.97 % to 23.12 % and 7.56 % to 91.66 % were observed in the presence of Pseudomonas sp, Lysinibacillu ssp. and Staphylococcus sp., respectively. All the test bacterial species showed some measure of efficiency in phosphate removal. For nitrate removal, the Lysinibacillus sp. did not exhibit remarkable nitrate removal ability at any of the temperatures. In addition, the optimum temperatures for phosphate removals were observed to be 30ºC to 40ºC for the Klebsiella sp. and Pseudomonas sp; and 30ºC to 35ºC for the Lysinibacillus sp. and Staphylococcus sp. For nitrate removal, optimum temperatures for removal were observed to be 25ºC to 40ºC, for the Klebsiella sp and 25ºC to 35ºC, for the Pseudomonas sp. and Staphylococcus sp. Conclusion: The study was able to reveal the optimum temperatures for phosphate and nitrate uptake in synthetic wastewater by the test bacterial species.

Influence of Top Dressing of Phosporus Through Complex Fertlizers on Nutrient Uptake and Economics of Rice.

A field experiment was conducted to study the effect of top dressing of phosphorus through complex fertilizers on rice during kharif 2009 on clayey soil at Agricultural college farm Bapatla. Phosphorus uptake was significantly influenced due to sources of P at different times of application. Significantly higher P uptake in grain and straw was recorded with application of P as basal and at maximum tillering stages either through DAP or by 20:20:0 which was on a par with three splits of DAP and 20:20:0 and basal application of DAP, SSP and 20:20:0. The available P in soil was found significant among the treatments at 30 DAT, whereas, at 60 and 90 DAT and at maturity, it was non significant. The available nitrogen and potassium in soil after the harvest of rice crop was found non significant. Gross and net returns and benefit cost ratio were higher with application of P through DAP in two equal splits at basal and maximum tillering stages followed by 20:20:0; whereas, BCR was the highest with DAP in three splits.

Matéria seca e acúmulo de macronutrientes na parte aérea das plantas de Crambe / Dry matter and macronutrients accumulation in crambe shoots

O crambe (Crambe abyssinica) tem bom potencial para produção de biodiesel pelo seu teor de óleo, além de ser uma alternativa para a rotação de culturas. Contudo, são escassas as informações sobre a demanda de nutrientes pelo crambe. O trabalho objetivou determinar a produção de matéria seca e o acúmulo de macronutrientes na parte aérea das plantas de crambe, em diferentes estágios de crescimento e desenvolvimento. O experimento foi realizado em delineamento experimental em blocos ao acaso, com cinco repetições. Foram coletadas amostras da parte aérea das plantas aos 14, 28, 42, 56, 70 e 84 dias após a emergência (DAE). Para cada coleta, as plantas foram dividas em folha (limbo e pecíolo), caule + ramos e frutos (cápsulas) e as amostras foram secas até peso constante para posterior determinação da matéria seca e teores de N, P, K, Ca, Mg e S. As folhas apresentam grande contribuição na produção de matéria seca nas fases iniciais de desenvolvimento das plantas. A partir do florescimento, a queda das folhas é acentuada e a contribuição dos caules+ramos é maior. Foi observada a seguinte demanda pelos nutrientes na parte aérea: N>Ca>P>S>K>Mg. Quanto às quantidades exportadas via colheita de grãos, seguiu-se a ordem: N>P>S>Mg>Ca>K. A produção de matéria seca da parte aérea das plantas e dos frutos é baixa. No entanto, em função do ciclo curto e da rápida transição entre as fases de florescimento e maturação dos frutos, a adubação de semeadura é fundamental para obtenção de rendimentos satisfatórios.

Crambe (Crambe abyssinica) has shown potential for biodiesel production because of high oil content in grains. Furthermore it is a viable option in crop rotation systems. Nevertheless, there are few studies about nutrient uptake by crambe plants. The aim of this work was to determine dry matter and nutrient accumulation in crambe shoots in different growth stages. The experiment was carried under a randomized complete block design with five replications. Shoot sampling was done at 14, 28, 42, 56, 70 and 84 days after seedling emergence. Each plant sample was separated in leaves (blade and petiole), stems+benches and fruit (capsules). The samples were dried, weighted and levels of N, P, K, Ca, Mg and S were determined. Plant leaves greatly contribute to dry matter production in initial stages of development. Leaf senescence is accentuated and the contribution from stems and branches is higher from flowering. The following nutrient demand by plant shoot was observed: N>Ca>P>S>K>Mg. Nutrients are exported by harvested grains as follows: N>P>S>Mg>Ca>K. Dry matter produced by shoots and fruit is low; however, sowing fertilization is essential to obtain satisfactory results due to a short plant cycle and fast transition period between flowering and fruit maturation.

Nitrogen management to improve the nutrient uptake, yield and quality parameters of scented rice under aerobic culture.

In the present study, the research results concluded that yield attributes of scented rice under aerobic culture responded up to 150 kg/ha nitrogen with four equal splits of nitrogen at ¼ basal + ¼ at active tillering + ¼ at panicle initiation and ¼ at heading. Grain and straw yields obtained higher values with highest level of nitrogen i.e. 175 kg/ha comparable with 150 kg/ha. Grain quality parameters milling percent, head rice recovery, kernel length, breadth, amylose content and protein content of rice registered significantly highest values with 150 kg N ha-1. Spilt application of nitrogen at ¼ basal + ¼ at active tillering + ¼ at panicle initiation and ¼ at heading was the most suitable stages for split application of nitrogen, which record significantly higher values of all quality parameters except amylose and protein content of grain. Nutrient uptake of N, P2O5 and K2O was influenced only by quantity of nitrogen applied and recorded higher with 175 kg/ha but not influenced by time of application of nitrogen except N uptake.

Influence of lead on growth and nutrient accumulation in canola (Brassica napus L.) cultivars.

Canola (Brassica napus L.) is commonly used as a hyper-accumulator for phytoextraction of heavy metals from soil and water. Like many other heavy metals, lead (Pb) contaminates soil, water and air and thus it is a great problem. This study was conducted to investigate toxic effects of Pb on growth and nutrient uptake in four canola cultivars. Each of four cultivars of canola (Con-II, Con-III, Legend and Shiralee) was subjected to four levels of Pb (0, 30, 60 and 90 mg Pb kg-1 of soil) from lead chloride [PbCl2]. Due to Pb toxicity, plant growth was adversely affected and relatively a severe reduction in root biomass (45.7%) was recorded. The Pb accumulation increased both in shoot and root, the highest being in root. The uptake of different nutrients, i.e., N, P, K, Ca, Mg, Zn, Cu and Mn was reduced (38.4, 32.8, 33.1, 49.6, 7.78, 52.0, 42.6 and 45.9%, respectively) in the shoots and that of N, Fe, Zn, and Cu in the roots (48.5, 33.2, 24.3 and 44.8%, respectively) of all canola cultivars. The root K, P, Zn and Mn and shoot P, Mg and Fe contents were less affected, the concentration of Pb, Ca and Mg in roots of all cultivars. Among canola cultivars Con-II and Con- III performed better than Legend and Shiralee in terms of growth (26.03%) and nutrient accumulation. Overall, plant growth and nutrient accumulation in the canola cultivars was hampered due to the presence of Pb.

Sunflower micronutrient uptake curves / Curva de absorção de micronutrientes na cultura do girassol

Most studies in the literature regarding the uptake of micronutrients [zinc (Zn), manganese (Mn), iron (Fe), copper (Cu) and boron (B) accumulation] by sunflower are old. For this reason, this work is aimed to establish curves of sunflower micronutrient accumulation in tropical edaphoclimatic conditions. The experiment was conducted in field on Rhodic Eutrudox, located at the experimental farm of Embrapa Soja in Londrina-PR, using the commercial hybrid BRS 191. The experimental design was completely randomized, with four replicates. The experimental units consisted of 14 lines with a spacing of 0.70 meter between lines and 25.0 meters in length, with final density of 42,858 plants per hectare. Plants samples were collected every 14 days after emergence. After each collection, plants were divided into petiole, leaf, stem, capitulum and achenes. They were dried until reaching constant weight. Then, dry matter was weighed and the concentrations of Zn, Mn, Fe, Cu, and B were determined in the vegetal tissue. Micronutrient uptake occurred faster in the phase initiated 42 days after emergence (DAE). Iron was the most absorbed micronutrient, accumulating higher amounts in the achenes as well as in relation to the total absorbed. Fe, Mn, Zn, B and Cu concentrations were 38.06, 19.68, 9.20, 8,62 and 4.27 mg plant-1, respectively.

Devido ao fato de a maioria dos trabalhos encontrados na literatura a respeito do acúmulo dos micronutrientes [zinco (Zn), manganês (Mn), ferro (Fe), cobre (Cu) e boro (B)] no girassol serem antigos, objetiva-se, com este trabalho estabelecer curvas de acúmulo de micronutrientes em um híbrido de girassol na condição edafoclimática dos trópicos. O experimento foi instalado no campo sobre Latossolo Vermelho distroférrico de textura argilosa, localizado na fazenda experimental da Embrapa Soja, em Londrina-PR, utilizando o híbrido comercial BRS 191. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições. As unidades experimentais foram constituídas de 14 linhas, com espaçamento de 0,70 m entre linhas e 25 m de comprimento, com densidade final de 42.858 plantas ha-1. As amostras das plantas foram coletadas em intervalos de 14 dias após a emergência. Após cada coleta, dividiram-se as plantas em pecíolo, folha, caule, capítulo e aquênios, sendo que as mesmas foram secas até peso constante, quando foram tomados os pesos da matéria seca e determinados os teores de Zn, Mn, Fe, Cu e B no tecido vegetal. A absorção de micronutrientes ocorreu em maior velocidade a partir dos 42 dias após a emergência (DAE). O Fe foi o micronutriente mais absorvido, acumulando maior quantidade tanto nos aquênios como em relação ao total absorvido. O acúmulo total de Fe, Mn, Zn, B e Cu foram 38,06, 19,68, 9,20, 8,62 e 4,27 mg planta-1, respectivamente.

Study on biofiltration capacity and kinetics of nutrient uptake by Gracilaria cervicornis (Turner) J. Agardh (Rhodophyta, Gracilariaceae)

The absorption efficiency and kinetic parameters (Vmax, Ks and Vmax:Ks) of the seaweed Gracilaria cervicornis for the nutrients NH4+, NO3- and PO4(3-) were evaluated. Absorption efficiency was measured by monitoring nutrient concentrations for 5 h in culture media with initial concentrations of 5, 10, 20 and 30µM. Kinetic parameters were determined by using the Michaelis-Menten formula. Absorption efficiencies for this algae were greater in treatments with lower concentrations, as evidenced by a reduction of 85.3, 97.5 and 81.2 percent for NH4+, NO3- and PO4(3-), respectively. Kinetic parameters show that G. cervicornis exhibits greater ability to take up high concentrations of NH4+ (Vmax=158.5µM g dw-1 h-1) and low concentrations of PO4(3-) (Ks=5µM and Vmax:Ks=10.3). These results suggest that this algal species has good absorption capacity for the nutrients tested and may be a promising candidate as a bioremediator of eutrophized environments.

Organic acid effect on calcium uptake by the wheat roots

This work evaluated the effect of the natural organic acids on the uptake of Ca by the wheat roots in a hydroponic solution. The following organic acids were evaluated: citric, oxalic, tartaric, malic, malonic, maleic, DL-malic, p-hydroxybenzoic, aconitic, and salicilic. The organic acids neither enhanced the root growth nor increased Ca uptake. The salicilic and malic acids were highly toxic and decreased the root growth. The citric, tartaric, maleic, aconitic, and salicilic decreased the Ca uptake by the roots due to their higher capacity to form the stable complexes with Ca in solution at pH 6.0. Decreasing the Ca valence from Ca++ to CaL+ or CaL2(0) through the organic ligand complexation reactions decreased the Ca uptake. The results suggested that the wheat roots do not absorb Ca-organic complexes.

Ácidos orgânicos possuem grupos funcionais com cargas negativas que complexam íons metálicos em solução. Este trabalho avaliou o efeito de ácidos orgânicos naturais na absorção de Ca pelas raízes de trigo. Foram avaliados os seguintes ácidos orgânicos: cítrico, oxálico, tartarico, málico, malônico, maleico, DL-málico, p-hidroxibenzoico, aconítico e salicílico. Os ácidos orgânicos não estimularam o crescimento das raízes e não aumentaram a absorção de Ca. Os ácidos salicílico e maleico diminuíram drasticamente o crescimento radicular. Os ácidos cítrico, tartárico, maleico, aconítico e salicílico diminuíram a absorção de Ca pelas raízes devido à maior capacidade de formar complexos estáveis com Ca em solução no pH 6,0. A redução da valência de Ca++ para CaL+ e CaL2(0), através das reações de complexação, diminuiu a absorção de Ca pelas raízes. Os resultados sugerem que os complexos de Ca-orgânico não são absorvidos pelas raízes de trigo.

Isolation, molecular characterization and growth-promotion activities of a cold tolerant bacterium Pseudomonas sp. NARs9 (MTCC9002) from the Indian Himalayas

A bacterium that grows and expresses plant growth promotion traits at 4°C was isolated from the rhizospheric soil of Amaranth, cultivated at a high altitude location in the North Western Indian Himalayas. The isolate was Gram negative and the cells appeared as rods (2.91 x 0.71 μm in size). It grew at temperatures ranging from 4 to 30°C, with a growth optimum at 28°C. It exhibited tolerance to a wide pH range (5-10; optimum 8.0) and salt concentrations up to 6 percent (wt/vol). Although it was sensitive to Rifampicin (R 20 μg mi-1), Gentamicin (G 3 μg mi-1), and Streptomycin (S 5 μg mi-1), it showed resistance to higher concentrations of Ampicillin (A 500 μg mi-1), Penicillin (P 300 μg mi-1), Polymixin B sulphate (Pb 100 μg mi-1) and Chloramphenicol (C 200 μg mi-1). The 16S rRNA sequence analysis revealed maximum identity with Pseudomonas lurida. The bacterium produced indole Acetic Acid (IAA) and solubilizes phosphate at 4, 15 and 28°C. It also retained its ability to produce rhamnolipids and siderophores at 15°C. Seed bacterization with the isolate enhanced the germination, shoot and root lengths of thirty-day-old wheat seedlings by 19.2, 30.0 & 22.9 percent respectively, as compared to the un-inoculated controls.

Produção de matéria seca e eficiência nutricional para P, Ca e Mg em leguminosas herbáceas / Dry matter production and nutritional efficiency for P, Ca and Mg in herbaceous legumes

As leguminosas para adubação verde têm sido introduzidas nos sistemas agrícolas para a recuperação de solos desgastados pelo uso intensivo. O objetivo desse trabalho foi avaliar a resposta de leguminosas herbáceas à aplicação de calcário e fósforo sobre a produção de biomassa e eficiência nutricional para o P, Ca e Mg. O experimento foi desenvolvido em casa-de-vegetação do Departamento de Ciência do Solo da Universidade Federal Rural da Amazônia, utilizando-se um Latossolo Amarelo distrófico coletado na profundidade de 0 - 20 cm, em Belém, PA. O delineamento experimental usado foi o de blocos ao acaso, com arranjo de tratamentos em um fatorial 3³, onde foram comparadas três espécies de leguminosas: mucuna preta (Stizolobium atterrimum), mucuna cochinchinensis (Stilozobium cochinchinensis) e feijão-de-porco (Canavalia ensiformes); três níveis de calagem: de calcário dolomítico (0, 4 e 8 t.ha-1) e de fósforo (0, 25 e 45 mg.dm-3), com quatro repetições cada um. Mucuna cochinchinensis e o feijão de porco produziram maiores quantidades de biomassa vegetal do que a mucuna preta, sendo que a primeira espécie acumulou maior quantidade de P e a segunda maior quantidade de Ca. Mucuna cochinchinensis apresentou maior eficiência de utilização de P, Ca e Mg na ausência da calagem. Nos solos intemperizados com baixa concentração de P, Ca e Mg, o feijão-de-porco e a mucuna cochinchinensis poderão ter melhor desempenho do que a mucuna preta, visto que apresentaram maior eficiência de translocação e de utilização desses nutrientes, respectivamente.

The legumes used for green manure have been introduced in agricultural systems for recovering degraded soils by intensive use. The objective of this work was to evaluate the response of herbaceous legumes to liming and P application on dry matter and its nutritional efficiency. The experiment was developed in greenhouse at the Soil Science Department of the Federal University Agricultural of Amazon (Brazil). Soil used was a dystrophic Yellow Latosol, sampled in the 0 - 20 cm depth. A randomized block experimental design was used with treatments arranged in a factorial 3³, comparing three legume species: velvet bean (Stizolobium atterrimum), "mucuna cochinchinensis" (Stilozobium cochinchinensis) and jack bean (Canavalia ensiformes); three doses of liming (0, 4 and 8 t ha-1 of limestone) and of triple superphosphate (0, 25 and 45 mg P dm-3 of soil), with four replications each one. Results showed that "mucuna cochinchinensis" and jack bean produced higher amounts of dry matter than velvet bean. The first species accumulated higher amount of P and the second species higher amount of Ca in the tissue. The "mucuna cochinchinensis" species showed higher use efficiency of Ca, Mg and P in the absence of liming. The jack bean and mucuna cochinchinensis can have better performance than velvet bean, in weathered soils with low concentration of P, Ca and Mg, since they presented higher translocation efficiency and use of these nutrients, respectively.