Matter Production Research Articles

К конструированию энтропийно–силовой модели расширения Вселенной, обусловленного гравитационно-индуцированным производством темной материи и влиянием обменной энтропии на событийном горизонте

Within the framework of Prigogin's gravitational theory of the geometry-matter connection that ensures the production of particles in a cosmological fluid, a single-fluid model of the evolution of a spatially flat, homogeneous and isotropic Universe is thermodynamically constructed. In order to obtain it, the continuity equation (energy conservation equation) was derived from the first law of thermodynamics taking into account the gravity-induced creation of matter and energy exchange processes on the visible horizon of the Universe. Based on this equation and the fundamental Friedman equation describing the expansion of the Universe, in the context of the entropic formalitу modified Friedman-Robertson-Walker equations were constructed to model various scenarios of the evolution of the flat Universe with matter production. In their derivation, several forms of exchangeable phenomenological entropies associated by assumption with the region of the visible cosmological horizon were used. The resulting generalized Prigogine model agrees well with the standard cosmological ?-model for cold dark matter and allows us to explain the accelerated expansion of the late Universe, providing its cosmological history without the introduction of new fields.

Identification of sulfur–oxidizing Thiothrix bacteria on microcrustaceans from the sulfidic groundwaters of Mangalia (southeastern Romania)

Movile Cave, located in southeastern Romania close to the Black Sea, is one of the most remarkable diversity hotspots worldwid with 52 species of invertebrates of which 37 are endemic (Brad et al. 2021). Due to the high concentration of hydrogen sulfide in its water, the primary production of organic matter in Movile Cave relies almost entirely on the chemoautotrophic activity of microorganisms, notably sulfur-oxidizing gammaproteobacteria belonging to the genus Thiothrix. In the presence of oxygen, these filamentous bacteria can oxidize hydrogen sulfide and reduce it into various sulfidic compounds, generating energy in the process. In sulfidic ecosystems, Thiothrix bacteria are frequently found free-living but also as epibionts or ectosymbionts growing on other organisms, such as amphipods (Flot et al. 2014). However, it is unclear whether Thiothrix bacteria also grow on microcrustaceans such as copepods or ostracods, of which several species are known from the sulfidic mesothermal aquifer of Mangalia, where Movile Cave is located. To find it out, we combined DNA sequencing using the reference bacterial 16S ribosomal RNA gene with morphological observations (including fluorescence microscopy). Our results reveal that Thiothrix bacteria are indeed present on microcrustaceans from Movile Cave and surrounding wells in the Mangalia region, highlighting the versatility of Thiothrix-crustacean associations in sulfidic ecosystems. This is the first report of an association between Thiothrix and groundwater microcrustaceans, and the second report of an association between Thiothrix and a nonmarine ostracod (Khalzov et al. 2021).

Silicon mitigates nutritional stress of nitrogen, phosphorus, and calcium deficiency in two forages plants

Forages are one of the most cultivated crops in the world. However, nutritional deficiency is common, specifically in N, P, and Ca in many forage-growing regions. Silicon (Si) can attenuate the stress caused by nutritional deficiency, but studies on Si supply’s effects on forage plants are still scarce. This research was carried out to evaluate whether the Si supply can mitigate the effects of N, P, and Ca deficiencies of two forages and the physiological and nutritional mechanisms involved. Two experiments were carried out with two forage species (Urochloa brizantha cv. Marandu and Megathyrsus maximum cv. Massai). We used nutrient solution under balanced nutrition conditions and nutritional stress due to the lack of N, P, and Ca combined with the −Si and +Si. The deficiencies of N, P, and Ca in both forages’ cultivation caused damage to physiological and nutritional variables, decreasing the plant dry matter. However, in both forage species, the Si addition to the nutrient solution decreased the extravasation of cellular electrolytes and increased the content of phenolic compounds, the green colour index, the quantum efficiency of photosystem II, the efficiencies of use of N, P and Ca and the production of shoot dry matter. The beneficial effects of Si were evidenced in stressed and non-stressed plants. The research emphasised the advantage of using Si to grow U. brizantha and M. maximum under N, P, and Ca deficiency, contributing to their sustainable cultivation.

Gravitational portals in the early Universe

We consider the production of matter and radiation during reheating after inflation, restricting our attention solely to gravitational interactions. Processes considered are the exchange of a graviton, ${h}_{\ensuremath{\mu}\ensuremath{\nu}}$, involved in the scattering of the inflaton or particles in the newly created radiation bath. In particular, we consider the gravitational production of dark matter (scalar or fermionic) from the thermal bath as well as from scattering of the inflaton condensate. We also consider the gravitational production of radiation from inflaton scattering. In the latter case, we also derive a lower bound on the maximal temperature of order of ${10}^{12}\text{ }\text{ }\mathrm{GeV}$ for a typical $\ensuremath{\alpha}$-attractor scenario from $\ensuremath{\phi}\ensuremath{\phi}\ensuremath{\rightarrow}{h}_{\ensuremath{\mu}\ensuremath{\nu}}\ensuremath{\rightarrow}$ Standard Model fields (dominated by the production of Higgs bosons). This lower gravitational bound becomes the effective maximal temperature for reheating temperatures, ${T}_{\mathrm{RH}}\ensuremath{\lesssim}{10}^{9}\text{ }\text{ }\mathrm{GeV}$. The processes we consider are all minimal in the sense that they are present in any nonminimal extension of the Standard Model theory based on Einstein gravity and cannot be neglected. We compare each of these processes to determine their relative importance in the production of both radiation and dark matter.

Oat catch crop efficacy on nitrogen leaching varies after forage crop grazing

This study tested the effect of oat catch crops on mineral nitrogen (N) leaching losses from cool season fodder beet grazing. Undisturbed soil monolith lysimeters were collected from two grassland sites with soils featuring contrasting texture and water holding capacity (WHC) characteristics. After simulated fodder beet grazing in late autumn or winter, synthetic dairy cow urine was applied. Nitrogen leaching losses were measured from lysimeters sown with oats after urine application and compared with those under fallow conditions until spring. Oat dry matter (DM) production and N uptake measurements were obtained. Sowing oats reduced total mineral N leaching losses by up to 59%. Reductions in mineral N leaching were inconsistently affected by soil type but were strongly influenced by urine application timing. Nitrogen uptake by oats (52–143 kg N ha−1) drove reductions in N leaching losses compared with fallow soil. Oats yielded 4–17 t DM ha−1, and both yield and N uptake were strongly affected by urine application timing (winter > autumn) and soil type (high WHC > low WHC). Sowing oats after fodder beet grazing instead of leaving the ground fallow can reduce the environmental impacts of these systems, while simultaneously increasing annual feed supply. Catch crop gains can be maximised by avoiding or delaying autumn grazing of fodder beet, particularly on low WHC soils.

Isotopic and traits-based trophic diversity of Canadian Beaufort Sea benthic communities in relation to food supply

In the Arctic, climate-driven alterations to the quality and quantity of organic matter reaching the seafloor will likely affect benthic food web function. We used biomass-weighted diversity measures based on trophic traits (those related to feeding behaviours, e.g., mobility, size, food source), stable isotope ratios (δ15N and δ13C), and taxonomy to assess linkages between benthic food web structure and indicators of food supply in the shelf and slope ecosystems of the Canadian Beaufort Sea and Amundsen Gulf (down to 500 m). Benthic communities across both regions used a similar diversity of sedimentary organic matter sources according to stable isotopes, despite known differences between regions in organic matter input and benthic–pelagic coupling. Shelf-edge and upper-slope communities exhibited relatively high trophic trait diversity, which likely reflected the exploitation of pulsed food inputs associated with dynamic processes at the shelf break that affect the production and advection of organic matter to the benthos. Pairwise relationships between trophic traits and sedimentary proxies of benthic food supply were not significant at the regional scale. However, cluster analyses supported the notion that trophic trait composition was influenced by proximity to the shelf edge, where food supply is influenced by episodic events that may not be reflected by in situ sedimentary proxies. Our findings add to growing evidence that evaluating trophic traits composition may provide more information regarding functional responses to changes in benthic food supply than either isotopic or taxonomic diversity indices alone.

Flooding effects on population and growth characteristics of Bolboschoenus planiculmis in Momoge wetland, northeast China

Due to the interactive influences of climate change and human activities, flooding events are becoming an increasingly more serious abiotic stress in wetland ecosystems. Bolboschoenus planiculmis is a critical target plant species for the restoration of degraded wetland in the Momoge National Nature Reserve (MNNR), Northeast China. To investigate B. planiculmis growth response under different flooding conditions, we conducted comparative field studies of its population traits and ecological characteristics under alternate wetting to flooding (AF) and continuous flooding (CF) conditions. Under AF conditions, the B. planiculmis population significantly increased, its cover differed significantly (except June) compared to CF conditions, and flood stress significantly promoted its height. Flood events caused seasonal changes in morphological characteristics, especially stem and leaf length which increased in the growth period, and leaf width and area that significantly differed in June. B. planiculmis tuber biomass under CF condition was significantly higher than AF condition in May. B. planiculmis biomass was greater in AF, compared to CF conditions in the mid-late growth period, and its below-aboveground biomass ratio initially decreased before increasing, which indicated that the growth strategy was a trade-off between matter production and allocation during flooding. Flooding conditions had a significant effect on population traits and ecological characteristics, and AF conditions more strongly promoted B. planiculmis population development. Appropriate seasonal regulated floodwater management during the growth stage will assist B. planiculmis growth. Our findings provide invaluable supporting information for B. planiculmis MNNR wetlands restoration and management.

The in situ Production of Aquatic Fluorescent Organic Matter in a Simulated Freshwater Laboratory Model.

Dissolved organic matter (DOM) is ubiquitous throughout aquatic systems. Fluorescence techniques can be used to characterize the fluorescing proportion of DOM, aquatic fluorescent organic matter (AFOM). AFOM is conventionally named in association with specific fluorescence “peaks,” which fluoresce in similar optical regions as microbially-derived proteinaceous material (Peak T), and terrestrially-derived humic-like compounds (Peaks C/C+), with Peak T previously being investigated as a tool for bacterial enumeration within freshwaters. The impact of anthropogenic nutrient loading on the processing of DOM by microbial communities is largely unknown. Previous laboratory studies utilizing environmental freshwater have employed growth media with complex background fluorescence, or very high nutrient concentrations, preventing the investigation of AFOM production under a range of more representative nutrient concentrations within a matrix exhibiting very low background fluorescence. We describe a laboratory-based model with Pseudomonas aeruginosa that incorporates a low fluorescence growth matrix consisting of a simulated freshwater (SFW), representative of low-hardness freshwater systems allowing controlled nutrient conditions to be studied. The effects of microbial processing of DOM as a function of available nitrogen, phosphorous, and dissolved organic carbon (DOC) in the form of glucose were investigated over 48 h at highly resolved time increments. The model system demonstrates the production of a range of complex AFOM peaks in the presence and absence of DOC, revealing no linear relationship between cell numbers and any of the peaks for the bacterial species studied, with AFOM peaks increasing with microbial cell number, ranging from 55.2 quinine sulfate units (QSU) per 106 cells to 155 QSU per 106 cells (p < 0.05) for Peak T during the exponential growth phase of P. aeruginosa under high nutrient conditions with 5 mg L−1 DOC. Nutrient and DOC concentration was found to cause differential production of autochthonous- or allochthonous-like AFOM, with lower DOC concentrations resulting in higher Peak T production relative to Peaks C/C+ upon the addition of nutrients, and high DOC concentrations resulting in higher Peak C/C+ production relative to Peak T. Our results show the production of allochthonous-like AFOM from a simple and non-fluorescent carbon source, and provide uncertainty in the use of Peak T as a reliable surrogate for specific bacterial enumeration, particularly in dynamic or nutrient-impacted environments, pointing toward the use of fluorescence as an indicator for microbial metabolism.

Tannery Sludge Applied in High Doses in Elephant Grass as an Alternative Fertilization

ABSTRACT Tannery sludge has great potential for use in agriculture, however it is a potentially toxic waste, and it is necessary to establish the ideal dose for each crop. The objective of this study was to evaluate the influence of fertilization with liquid tannery sludge on growth, chlorophyll a fluorescence and gas exchange of Pennisetum purpureum in two production cycles. A 2 × 6 + 1 split plot scheme was used, where the first factor was composed of two productive cycles, the second factor different fertilizations doses: 0, 30, 70, 110, 150, 190 t ha−1 of liquid tannery sludge and an additional treatment with nitrogen, phosphorus and potassium control. Plant height, number of leaves and tillers, canopy and stem diameter, leaf area, dry matter, chlorophyll index (SPAD), chlorophyll a fluorescence and gas exchange were evaluated. The highest production of total dry matter was observed in the second production cycle. The range between 72–100 t ha−1 of liquid tannery sludge showed the greatest gains in growth and production of elephant grass. At doses above 150 t ha−1 of liquid tannery sludge, the photochemical apparatus begins to show possible damage to the photosystem II (PSII) and reductions in gas exchange.

Differentiation of the Generation Potential of the Menilite and Istebna Beds of the Silesian Unit in the Carpathians Based on Compiled Pyrolytic Studies

The study of the source rocks was carried out with the use of various analytical methods in order to assess their generation potential and to predict the decomposition products of organic matter. The selected samples from the Menilite Beds from the Silesian and Dukla units, as well as the Istebna layers from the Silesian unit, which are classified as weak and medium source rocks in the Carpathian oil system, were examined. The generation potential and type of the products obtained from the pyrolysis of the analyzed source rocks, despite the often comparable overall content of organic matter, are significantly different. Menilite shale generated a higher abundance of hydrocarbons (alkanes, alkenes, and isoalkanes) by stage pyrolysis, which suggested that the organic matter of Menilite shale is different from the Istebna source rocks. Moreover, the thermogravimetric analysis showed a two-stage weight loss in the case of Menilite shales, while the Istebna shales were characterized by a one-stage weight loss at higher temperature. For the Istebna layers, n-alkanes from the C1–C5 range were detected as the main pyrolysis products, which proves the gas-forming type of the organic matter dispersed in these sediments. Rock-Eval analyses showed that the organic matter reached a degree of maturity corresponding to the early thermocatalytic processes (the initial oil window stage) and therefore was able to generate liquid and gaseous hydrocarbons. The comparison of the decomposition temperatures of the organic matter from the Rock-Eval and TG analyses allowed us to conclude that both measurements correlate well and can be equally used to assess the level of thermal transformations of organic matter.

Floristic diversification of spreading liverseed grass pasture according to different cutting intensities, obtained by grazing simulation

This study aimed to evaluate the impacts of different forage cutting intensities, obtained by grazing simulation, on the floristic diversity and productivity of a pasture cultivated with spreading liverseed grass. The experiment was set up in a randomized block design, with four replications and treatments arranged in a 5 × 2 factorial scheme, with five levels of cutting intensity of the simulated grazing (0, 25, 50, 75, and 95% of the forage canopy) associated with two levels of weed coexistence (presence and absence). The evaluations of floristic diversity, number of individuals, and total dry matter of weeds were obtained at 15, 30, 45, 60, and 90 days after grazing simulation (DAGS). All plots were evaluated at the end of the experimental period (90 DAGS) for the amount of dry biomass produced by the pasture. The results showed that higher forage cutting intensities, obtained by grazing simulation, increased the floristic diversity, the number of individuals, and the dry matter accumulated by weeds in a pasture grown with spreading liverseed grass, reducing by up to 56% the production of total dry matter of the forage.

USES OF BIOFERTILIZATION TO PRODUCE TROPICAL GRASS FORAGE IN QUINTANA ROO MEXICO

The objective of this study was to evaluate the biofertilizers effect in Panicum maximaum (cv. Mombaza) and Brachiaria brizantha tropical grasses production. Microorganisms were obtained in rhizosphere of plants. To establish an effective symbiosis with native strains of Azospirillum, Azotobacter and mycorrhizal fungi, experiments were carried out in greenhouse and field. The biofertilizers used in greenhouse were combined (CC), semisolid medium Nitrogen free with malate as nitrogen source (NFB), Azotobacter (azot) and Azospirillum (Azos). For mycorrhizal fungi, 6 treatments were used: T1-control, T2-fertilized, T3-brown spore, T4-honey spore, T4-black spore and T5-commercial spore. The microorganism used in field were those that showed effectivity in greenhouse. The treatments in field were T1: control, T2: inorganic fertilizer, T3: Azospirillum + Azotobacter, T4: mycorrhizal and T5: commercial biofertilizer. The variables evaluated were dry weight (DW), radicular weight (RW), radicular volume (RV), stem diameter (SD) and total height (TH). Results for B. brizantha indicate differences (P≤0.05). Application of Azospirillum + Azotobacter (T3) favored the development of the height of the plant and the diameter of the stem. The commercial biofertilizer (T5) increased the production of dry matter with 0.99 kg/m2. In respect with P. maximum (cv. Mombaza) grass, they were not detected significative differences (P≥0.05) between treatments, however, the biological results showed that inorganic fertilizer (T2) increased the dry matter production with 1.34 kg / m2 in comparison with Azospirillum + Azotobacter (T3) that showed 0.72 kg / m2.

Experimental characterization of mixing and flow field in the liquid plugs of gas\u2013liquid flow in a helically coiled reactor

Flow mixing of two miscible liquids with the addition of gas bubbles is a process often found in industrial chemical apparatus for the production of primary matter. The ongoing optimization of such processes also involves the transformation of batch to continuous mode operation. In that case, the use of helically coiled tubes is an interesting alternative, since those reactors have narrow residence time distributions, very good radial mixing properties and excellent mass transfer can be realized between gases and liquids. For these reasons, in this study the mixing of two miscible liquids with addition of air bubbles in gas–liquid flows has been characterized in a horizontal helically coiled reactor in the laminar flow regime at {text{Re}}_{{{text{total}}}} = 300 ldots 1088. Eight different superficial liquid velocities and five superficial gas velocities were investigated. In order to characterize mixing in the liquid plugs between two bubbles, laser-induced fluorescence of resorufin was used and particle image velocimetry has been employed to characterize the flow field. Pseudo-3D-visualizations of the resorufin concentration and the Q-criterion, representing the mixing efficiency and vorticity, respectively, were established for individual liquid plugs from the time-resolved measurement results. A time-resolved mixing coefficient, as well as a mean mixing coefficient obtained from multiple liquid plugs, is calculated from the fluorescence images for all examined flow conditions. The experimental results clearly show an increase in the mixing coefficient compared to single-phase conditions, caused by the bubbles. However, distinct mixing pattern, depending on the flow structure, can be recognized on different locations inside the liquid plug. Compared to a stationary case without air bubbles, mixing is worse behind the bubbles and increases inside the plug, reaching a maximum mixing coefficient in front of the next bubble. Overall the mixing coefficient is always increased by the presence of the bubbles. Pseudo-3D-visualizations of the Q-criterion and the vorticity show the presence of secondary vortices right in front of the bubbles, shifted to the outer tube walls, and in addition to the steady Dean vortices. In small plugs, these secondary vortices appear in the whole plug and increase the mixing coefficient drastically.Graphical

Effect of quantities of seeds on dry matter production of parts of the plant and on yield and its components of varieties of barley Hordeum vulgare L

A field experiment was carried out at the Second Agricultural Research and Experiments Station of the College of Agriculture / University of Al-Muthanna in Al Bandar region, in the winter season (2020-2021), to study the effect of seed quantities on the production of dry matter of varieties of barley, and the experiment was applied according to the arrangement of the plates. The split was according to a randomized complete block design(RCBD) with three replications. The experiment included the main factor of five seed quantities (20, 40, 60, 80, 100 and 120 kg ha-1), and the secondary factor included two of varieties barley (Aksad, Ibaa265). The results showed that the quantities of seeds were significantly superior in all yield characteristics and the dry matter of the plant parts in the barley crop, where the quantity of seeds 80 kg ha-1 was superior to the dry weight of stems, the dry weight of leaves in the stage of full maturity and the number of grains in the spike, which reached Their averages were (21.12 g, 15.30 g, and 50.1 grain spike-1) respectively, and the 60 kg ha-1seed quantity outperformed in the dry weight of the fully ripened ears, the dry plant weight and the weight of 1000 grains, as their averages were (41.41 g and 77.08 g and 26.28 g) respectively, and the quantities of seed 120 kg ha-1outperformed in the number of spikes and grain yield, as they reached 371.11 spike m-2and 6.47 tons ha-1). The lowest seed level of 40 kg ha-1gave the lowest averages for most of the studied traits, as it gave the lowest average dry weight of stems, leaves and ears, and the dry weight of the plant in the fully mature stage, and the weight of 1000 grains, where their averages were (15.53 g, 12.20 g, 24.21 g, 51.94 g and 24. 1 gm) sequentially. As for the cultivars, there were no significant effects, but the cultivar ibaa 265 was superior in most of the studied traits compared with the cultivar Aksad. With regard to the interaction between the quantities of seeds and varieties, there were no significant effects between them.

Association of Root and Leaf Silicon Application Decreases the C/Si Ratio, Increasing Carbon Gain and Dry Mass Production in Peanut Plants

ABSTRACT Silicon (Si), depending on the application method, can benefit the growth of peanuts by stoichiometric modification of carbon (C); however, this is not yet well known in this culture. Therefore, the objective was to evaluate whether different application forms of Si increases the growth of peanut plants due to stoichiometric changes C/Si and consequently stomatal conductance and photosynthesis. The experiment was carried out in a greenhouse in pots with nutrient solution using peanut plants cultivating granoleic. The treatments were: control, without Si application (-Si); Si via root (Si R) (2.0 mmol L−1) Si via leaf (Si F) (4.0 mmol L−1) and Si via root associated with leaf (Si R + F), arranged in randomized blocks with five repetitions. The variables analyzed were: Si content and accumulation, carbon percentage, C/Si ratio, efficiency of C use, photosynthesis, stomatal conductance, transpiration, dry matter and productivity. The application of root Si plus leaf spray is efficient to increase the accumulation of the element in the aerial part of the peanut. The benefit of Si in the growth of peanut plants is due to its effect of modifying the stoichiometric C/Si ratio in the plant, which resulted in an increase in the photosynthetic rate and, consequently, in the efficiency of the use of C and the production of dry matter and productivity of the plant.

Sources and doses of nitrogen in plant cane production and residual effect on the first ratoon of sugarcane in a savannah Red Oxisol

The expansion of sugarcane cultivation, especially in areas with low natural soil fertility, such as savannah regions, requires greater efficiency in the application of nutrients, mainly nitrogen (N). The objectives of this study were to evaluate the effects of the application of different sources and doses of nitrogen on the dry matter yield and productivity of sugarcane in the plant cane cycle and the residual effect of such application on the first ratoon cycle of sugarcane (var. SP80-1816) cultivated in a dystrophic Red Oxisol. The experimental design was a randomized complete block design analyzed in a factorial scheme of 2 × 4 with three replications. The evaluated factors consisted of two sources of N (ammonium nitrate (AN) and urea (U)) and four doses of N (0, 60, 120 and 180 kg ha-1). Samples of the aerial part of the sugarcane were collected. The structural components of the aerial part were separated, and the leaf dry matter (LDM), stalk dry matter (SDM) and dry matter of the aerial part (DMAP) were analyzed. The productivity of stalks (PS) was determined by weighing all stalks present in the useful area of each plot. In the plant cane cycle, AN resulted in greater gains in the SDM and PS of sugarcane than did U. In the first ratoon cycle, a residual effect was observed in response to N application, which showed an increase in SDM and PS. Under the conditions of this study, to achieve a higher PS in both cycles, the application of 180 kg N ha-1 is recommended

Relativistic freeze-in with scalar dark matter in a gauged B \u2212 L model and electroweak symmetry breaking

We explore relativistic freeze-in production of scalar dark matter in gauged B − L model, where we focus on the production of dark matter from the decay and annihilation of Standard Model (SM) and B − L Higgs bosons. We consider the Bose-Einstein (BE) and Fermi-Dirac (FD) statistics, along with the thermal mass correction of the SM Higgs boson in our analysis. We show that in addition to the SM Higgs boson, the annihilation and decay of the B − L scalar can also contribute substantially to the dark matter relic density. Potential effects of electroweak symmetry breaking (EWSB) and thermal mass correction in BE framework enhance the dark matter relic substantially as it freezes-in near EWSB temperature via scalar annihilation. However, such effects are not so prominent when the dark matter freezes-in at a later epoch than EWSB, dominantly by decay of scalars. The results of this analysis are rather generic, and applicable to other similar scenarios.

Performance of Different Green Manuring Crops in Bangladesh

An experiment was conducted at Sher-e-bangla Agricultural University during May to July, 2016 to examine the morpho-physical potentiality of eight green manure species and these species are viz. Sesbania aculeata, Sesbania rostrata, Crotalaria juncea, Vigna unguiculata, Vigna mungo, Vigna radiata, Leucaena leucocephala and Mimosa pudica. Leaves number, biomass production and nodulation are an important character of any green manuring crops as these crops are very potential for increasing soil fertility after incorporation. The growth habits of these species were studied from 15 DAS to 45DAS whereas dry matter/plant and nodulation data were taken from 25 DAS to 50DAS. At 45DAS, Sesbania aculeata, Sesbania rostrata and Vigna unguiculata shown 53% to 149% higher plant height compared to Vigna mungo, although C. juncea performed better at 30DAS compared to V. unguiculata. Again, C. juncea along with S. rostrata and S. aculeata gave the highest fresh biomass (24% to 72%), dry biomass (2.6t/ha to 5.25t/ha), dry matter plant-1 (60% to 83%) and nodulation compared to rest green manures at 45DAS whereas V. unguiculata produced higher dry matter plant-1 at 20DAS but later it declined insignificantly at 50DAS.The lowest performance was observed from V. mungo followed by V. radiata and M. pudica. It was shown that S. rostrata, S. aculeata, C. juncea, V. unguiculata and L.leucocephala performed better regarding biomass, dry matter and nodule production.&#x0D; Res. Agric., Livest. Fish.8(1): 25-31, April 2021

DÉFICIT HÍDRICO EN MAÍZ AL CONSIDERAR FENOLOGÍA, EFECTO EN RENDIMIENTO Y EFICIENCIA EN EL USO DEL AGUA

La presencia de períodos de disponibilidad hídrica baja y las eficiencias de riego bajas obligan a los distritos de riego (DR) a implementar acciones como la reducción de la superficie cultivada y el número de riegos de los cultivos. Esto, causa en muchos casos, impactos negativos en rendimiento al no aplicarse en forma científica. El objetivo de esta investigación fue evaluar de manera experimental el efecto del estrés hídrico a partir de la fenología, en los componentes del rendimiento y en el uso eficiente del agua del cultivo de maíz (Zea mays L.). El experimento se realizó en el distrito de riego DR-075, durante el ciclo otoño-invierno (OI) 2012-2013 y se evaluaron cuatro tratamientos (T) de déficit hídrico y un testigo (TES) diseñados a partir de la función FAO que relaciona el déficit hídrico con el rendimiento. T1 recibió dos riegos de auxilio (RA) distribuidos en las etapas V12 y R2; T2 recibió tres RA distribuidos en V9, R1 y R3; T3 recibió cuatro en V7, V12, R1 y R3-R4. T4 cinco RA en V5, V12, R1, R3 y R4. El TES recibió cuatro RA distribuidos igual que T3, pero aplicados en forma convencional. Las variables evaluadas fueron: eficiencia de aplicación (EA), materia fresca (MF), materia seca (MS), rendimiento de grano (Ya), índice cosecha (IC) y productividad del agua (PA). El seguimiento de riegos y fenología se realizó con la plataforma informática IRRIMODEL complementada con observaciones de campo; el monitoreo de la humedad del suelo se realizó con un sensor portátil tipo TDR. Los resultados proporcionaron información científica para manejar el riego del cultivo de maíz considerando fenología, bajo condiciones normales y de disponibilidad hídrica restringida. En el primer escenario se debe evitar el quinto riego de auxilio y en el segundo, utilizar el calendario de tres auxilios (T2) para obtener eficiencias de aplicación iguales o mayores a 64%.

Viabilidad del uso de cenizas de vinaza como fertilizante para forrajeras

Fue evaluada la utilización de cenizas de vinaza como fertilizante para forrajeras. La vinaza fue llevada a mufla a 600ºC por 90 minutos para producción de las cenizas. Se sembró la forrajera Urochloa brizantha - cv. Marandu, en bolsas plásticas de polietileno que se mantuvieron en casa de vegetación. Los tratamientos utilizados fueron la aplicación de ceniza de vinaza en cantidades equivalentes a 0, 100, 250, 500, 1000 kg/ha. Las plantas fueron cortadas con 30 días y 60 días para evaluar la producción de materia seca (MS) y materia verde (MV). En el suelo enriquecido, se retiró una muestra para realizar análisis. Hubo corrección de pH del suelo y aumento de los macrominerales fósforo, potasio, calcio y magnesio. El tratamiento con 100 kg/ha se mostró más eficaz e elevó en promedio el 18,5% la producción de MV y el 24% la producción de MS de la forrajera estudiada. Se concluye que el uso de cenizas de vinaza es una potencial fuente de minerales para forrajeras.