Initial Growth Phase Research Articles

Aluminum resistance of malting barley

Background. Barley is the second cereal crop in Russia in terms of its importance and production volume. It is used for food, feed, and industrial purposes. The production of malting barley in Russia exceeds 1.5 million tons; each year the area under this crop increases by 10–15%, reaching 600,000– 800,000 hectares. Barleys suitable for brewing must have certain physicochemical and technological properties. The main requirements for raw materials are presented in GOST 5060-86 (state standard for malting barley). An important condition for obtaining sustainable harvests is the development and utilization of cultivars resistant to a set of edaphic stressors. The purpose of this work was searching for resistant cultivars for use in targeted breeding.Materials and methods. The material for the study included 161 spring barley cultivars for brewing from the collection of plant genetic resources held by VIR. The laboratory assessment of aluminum tolerance in barley accessions was carried out at the initial phases of plant growth and development, using the method of calculating root and shoot length indices. The tested malting barley was classified into five resistance groups.Results and conclusions. Cultivars resistant to Al3+ ions were identified among different ecogeographic groups of malting barleys. The trait had a wide range of variability in terms of both the root length index (0.17–0.95) and shoot length index (0.47–0.99). Accessions with high resistance to ionic (Al3+) stress can be used in barley breeding targeted at the development of high-yielding malting cultivars most adapted to harmful environmental factors.

Carbon reservoirs in shade-tolerant morphotype of Paubrasilia echinata are more susceptible to humidity and temperature changes than sun-tolerant morphotype

Given the eminent climate changes and the importance of carbon dynamics in the growth and survival of plants, we investigated how the non-structural carbohydrates – NSC – and cell wall polymers – CWP (cellulose, hemicellulose, and lignin) – from sun-tolerant and shade-tolerant plants will respond to changes in vapor pressure deficit (VPD) and temperature (temp.) of atmosphere predicted for the southeast region of Brazil for the next decades. We used plants of two morphotypes of Paubrasilia echinata as a biological model. This species presents intraspecific variations from each other in leaf morphology and growth concerning luminosity in the initial phase of growth. The small morphotype is shade-tolerant and the medium morphotype is tolerant to full sun. The work was carried out in greenhouses adjusted with the combination of the higher and lower VPD and temp., constituting 4 enviroments: 1) 0.4 KPa – 19.8 °C, 2) 0.5 KPa – 23.8 °C, 3) 2.0 KPa – 25.1 °C, and 4) 1.1 KPa – 14.9 °C. On day 125 after the start of the experiment, we determined the concentrations of NSC and CWP in the root, stem, and leaves. The shade-tolerant morphotype showed an increase in sugar concentration in the environment where the plants grew the most (2.0 KPa – 25.1 °C). In this same environment, the NSC concentrations of the shoot organs increased in the sun-tolerant morphotype. The 0.4 KPa – 19.8 °C reduced the cellulose and lignin concentrations of the shade-tolerant morphotype and promoted the hemicelluloses of the sun-tolerant morphotype. The NSC and CWP allocation proved to be more influenced by VPD and temp. variations in the shade-tolerant than the sun-tolerant morphotype. We conclude that warming and lower atmospheric humidity could inhibit the axial stem growth of sun-tolerant juvenile plants. Warming, regardless of atmospheric humidity variations, will not affect the cellulose and lignin levels of stem, and consequently, the wood quality of shade- and sun-tolerant plants. However, hemicelluloses concentrations of sun-tolerant plants may decline in a warmer and less humid atmosphere.

Impact of Biochar Application on Germination Behavior and Early Growth of Maize Seedlings: Insights from a Growth Room Experiment

Reduced germination and early crop maturity due to soil compaction, nutrients stress, and low moisture are major constraints to achieve optimum crop yield, ultimately resulting in significant economic damages and food shortages. Biochar, having the potential to improve physical and chemical properties of soil, can also improve nutrients and moisture access to plants. In the present study, a growth room experiment was conducted to assess biochar influence on maize seed germination, early growth of seedlings, and its physiological attributes. Corn cob biochar (CCB) was mixed with soil at different rates (0.5%, 1%, 1.5%, 2%, 2.5%, and 3% w/w) before seed sowing. Results obtained showed that increasing CCB application rate have neutral to positive effects on seed germination and seedling growth of maize. Biochar addition at the rate of 1.5% (w/w) significantly increased shoot dry biomass (40%), root dry biomass (32%), total chlorophyll content (a and b) (55%), germination percentage (13%), seedling vigor (85%), and relative water content (RWC) (68%), in comparison to un-amended control treatment. In addition to this, it also improved germination rate (GR) by 3% as compared to control treatment, while causing a reduction in mean emergence time (MET). Moreover, application of biochar (3%) also resulted in enhancement of antioxidant enzyme activity, particularly superoxide dismutase (SOD) and catalase (CAT) by 13% and 17%, respectively. Conclusively, biochar application is an attractive approach to improve the initial phase of plant growth and provide better crop stand and essential sustainable high yields.

Dynamic ecophenotypy in the Silurian Monograptidae (Graptolithina)

ABSTRACTThe monograptids from the Wenlock and Ludlow (mid- to late Silurian) of the palaeotropical Baltic Basin exhibit thickened ring structures (sicular annuli) over their initial phase of growth. Appearing before the lundgreni extinction event, they persisted throughout the remainder of the Silurian, fluctuating in number over that period. To better understand the mechanisms controlling their development and variation, counts of sicular annuli were taken from three well cores in Lithuania, compared between species in each sample and compared with contemporaneous gamma ray data, accompanied by the stable isotope (δ13C), and acritarch diversity data. Mean counts of annuli fluctuated greatly over the studied interval, but showed negligible variation between species, indicating that the trait is ecophenotypic. The fluctuation in annulus presence aligned with variations in fourth- and fifth-order cycles derived from the gamma ray trends, which represent significant sea level fluctuations, δ13C ratios, and primary productivity, suggesting that annuli were more plentiful in high-stand states which are associated with the wetter climate and more productive conditions, whereas dryer, less productive conditions were not conducive to annulus development. In light of this evidence, we hypothesise that the action of upwelling as a result of intensified storm events during wetter periods would have encouraged phytoplankton blooms, increasing construction of annuli. These results show the potential utility of sicular annuli in the study of Silurian climate change and give new insights into graptolite palaeoecology.

Salt and Drought Effect on Germination and Initial Growth of Lavandula stoechas: A Potential Candidate for Rehabilitation of the Mediterranean Disturbed Coastal Lands

Abstract Information relating to germination and seedling emergence of a plant aids in determining the species spatiotemporal distribution and also facilitates in designing appropriate plant management strategies within an ecosystem. Lavandula stoechas L. (Lamiaceae), a naturally occurring shrub, is particularly used in pharmaceutical and cosmetic industries. This species, indeed, has the potential for rehabilitation of degraded costal lands. However, various aspects of its seed biology have not yet been recognised. Here, we aimed to assess the effects of different soluble salts (NaCl, CaCl2, MgCl2 and Na2SO4) and drought (as simulated by polyethylene glycol, [PEG]6000) on seed germination patterns and early seedling growth responses. Seeds treated with five iso-concentration (0–100 mM) salinities and five PEG6000 (0 to −1 MPa) levels were incubated in a controlled germinator set at 20°C. The preliminary results revealed that seeds of L. stoechas lacked primary/innate dormancy and they germinated abundantly (89.2% germination) and fast (7.4% day−1) in the absence of stress. Regardless of the kind of salt applied, the germination percentage (GP) and germination rate index (GRI) fell significantly with increasing salinity, and germination ceased completely at 100 mM Na2SO4. In fact, the salinity tolerance index (STI) showed that, among all salts tested, Na2SO4 appeared to have more inhibitory action on germination. In addition, L. stoechas was found to be tolerant to moderate salty stress (<50 mM) in early growth phase. The salt solution parameters (i.e. concentration, electrical conductivity [EC] and salt content) were best correlated with seed/seedling metrics. pH was not a good predictor for salt effects at the germination/seedling stages. Overall, this species seems to be sensitive to drought at the germination and initial growth phases. The germination recovery potential of L. stoechas in both stresses stipulates that this species can be regarded as a promising candidate in the rehabilitation of Mediterranean disturbed coastal habitats.

Magnetic reconnection and the Kelvin-Helmholtz instability in the solar corona

Context. The magnetic Kelvin-Helmholtz instability (KHI) has been proposed as a means of generating magnetohydrodynamic turbulence and encouraging wave energy dissipation in the solar corona, particularly within transversely oscillating loops. Aims. Our goal is to determine whether the KHI encourages magnetic reconnection in oscillating flux tubes in the solar corona. This will establish whether the instability enhances the dissipation rate of energy stored in the magnetic field. Methods. We conducted a series of three-dimensional magnetohydrodynamic simulations of the KHI excited by an oscillating velocity shear. We investigated the effects of numerical resolution, field line length, and background currents on the growth rate of the KHI and on the subsequent rate of magnetic reconnection. Results. The KHI is able to trigger magnetic reconnection in all cases, with the highest rates occurring during the initial growth phase. Reconnection is found to occur preferentially along the boundaries of Kelvin-Helmholtz vortices, where the shear in the velocity and magnetic fields is greatest. The estimated rate of reconnection is found to be lowest in simulations where the KHI growth rate is reduced. For example, this is the case for shorter field lines or due to shear in the background field. Conclusions. In non-ideal regimes, the onset of the instability causes the local reconnection of magnetic field lines and enhances the rate of coronal wave heating. However, we found that if the equilibrium magnetic field is sheared across the Kelvin-Helmholtz mixing layer, the instability does not significantly enhance the rate of reconnection of the background field, despite the free energy associated with the non-potential field.

Absorption and use of different sources and doses of NPK in the growth of 'Capdeboscq' and 'Flordaguard' rootstocks

This study examined the effects of different sources and doses of fertilizers, as well as nutritional efficiency during the initial growth phase of rootstocks. The experiment was conducted at the Federal University of Pelotas, in a greenhouse. The experimental design consisted of completely randomized, in a three-factor scheme (2 x 2 x 4), represented by the combination of two peach rootstock cultivars (Capdeboscq and Flordaguard), two types of fertilizers (controlled release and ready availability) and four doses of fertilizer (0, 4, 8 and 12 g L−1), corresponding to a total of 16 treatments, with four replications, each including five plants. The dose of 4 g L−1 of readily available fertilizer induced superiority in the MST accumulation of the 'Capdeboscq' plants, however for the 'Flordaguard' was necessary a higher dose (8 g L−1). Higher doses than these provided a reduction in the accumulation in the phytomass, length and volume of the roots, suggesting sensitivity of the peach rootstocks to the excess of nutrients in the substrate. Despite the higher doses having induced superiority in the absorption efficiency, the lower dose (4 g L−1) of the ready-to-use fertilizer provided greater efficiency of use, which is why it is indicated for the fertilization of rootstocks, allowing greater benefit-cost. 'Capdeboscq' is suggested for use in the production of rootstocks because it exhibits greater efficiency in the use of N-P-K in view of the reduced absorption efficiency rates of these nutrients, in the lowest tested dose.

Space-time changes in the initial phase of modern climate warming

The initial phase of a temperature growth in different parts of the Earth has been examined. It is found that climate warming in the continental areas began 6–8 years earlier than in the oceanic areas. Climate warming in the sub-polar cyclonic circulation area in the North Atlantic has been started only after the beginning of the positive quasi-30-year phase of the Atlantic Multidecadal Oscillation (AMO), i. e. since 2000s. On the basis of the Singular Spectrum Analysis of the air temperature time series the continental areas are found, in which summer air temperature changes are synchronous with AMO on a decadal scale. In those regions, climate warming began with a 10–15 year lag in comparison to other continental areas. The highest level of statistical significance of the correlation between quasi-60-year AMO components and summer air temperatures is observed in Central and Eastern Europe (35–60° N, 10–45° E). This oscillation explains the decadal summer temperature changes within the range of ±(0.5–0.6) °C in Belarus. Climate warming intensifies in summer during the ascending AMO segment, while during the descending segment, which has started since around 2010, the decrease in the rate of growth of summer temperatures should be expected.

The stochastic dynamics of early epidemics: probability of establishment, initial growth rate, and infection cluster size at first detection.

Emerging epidemics and local infection clusters are initially prone to stochastic effects that can substantially impact the early epidemic trajectory. While numerous studies are devoted to the deterministic regime of an established epidemic, mathematical descriptions of the initial phase of epidemic growth are comparatively rarer. Here, we review existing mathematical results on the size of the epidemic over time, and derive new results to elucidate the early dynamics of an infection cluster started by a single infected individual. We show that the initial growth of epidemics that eventually take off is accelerated by stochasticity. As an application, we compute the distribution of the first detection time of an infected individual in an infection cluster depending on testing effort, and estimate that the SARS-CoV-2 variant of concern Alpha detected in September 2020 first appeared in the UK early August 2020. We also compute a minimal testing frequency to detect clusters before they exceed a given threshold size. These results improve our theoretical understanding of early epidemics and will be useful for the study and control of local infectious disease clusters.

Identification of two‐phase recovery for interpretation of coral reef monitoring data

Abstract The world's coral reefs are under threat as climate change causes increases in frequency and severity of acute thermal stress. This is compounded by chronic pressures including rises in sea surface temperature, overfishing and decline in water quality. Monitoring to understand the recovery dynamics of corals is paramount to enable effective management of coral reefs. While detailed mechanistic models provide insight into reef recovery patterns, colony scale monitoring is not viable for reefs over a large geographical extent, such as the Great Barrier Reef (GBR). Consequently, aggregated coral cover data are utilised in practice and phenomenological analysis directly applicable to these monitoring programmes is essential for reef health reporting. These analyses are especially challenging for assessment of recovery potential of reefs reduced to very low coral cover (<10%) after disturbance since standard modelling assumptions may not hold. Through the application of an innovative diagnostic approach modified from methods used in cancer cell biology, we found that almost 50% of reefs recovering from low cover exhibited a previously undocumented initial phase of slower growth per unit cover before sigmoid coral cover recovery trajectories were observed. Without properly accounting for these reduced growth periods, the expected performance of reefs may be overestimated immediately after disturbance events. The presence of two‐phase recovery patterns has a profound negative impact on the continued provision of ecological services from these reefs as major disturbance frequencies increase. Projections show that if the time between major disturbances is <5 years, then reefs with two‐phase growth are never likely to reach 15% cover. Synthesis and applications. This work provides a method to detect two‐phase recovery, the tendency for observed reef recovery to be slower than expected after a major disturbance. This phenomenon is observed across the Great Barrier Reef with serious implications for recovery potential as major disturbances occur more frequently due to climate change. Identification of reefs prone to two‐phase recovery can assist the triage of reefs for intervention actions in response to disturbances. Understanding mechanisms will inform interventions and management actions targeted towards the unique marine ecosystems across the world's reefs.

Socioeconomic and Geographic Characteristics of Hospitals Establishing Transcatheter Aortic Valve Replacement Programs, 2012-2018.

Despite the benefits of novel therapeutics, inequitable diffusion of new technologies may generate disparities. We examined the growth of transcatheter aortic valve replacement (TAVR) in the United States to understand the characteristics of hospitals that developed TAVR programs and the socioeconomic status of patients these hospitals served. We identified fee-for-service Medicare beneficiaries aged 66 years or older who underwent TAVR between January 1, 2012, and December 31, 2018, and hospitals that developed TAVR programs (defined as performing ≥10 TAVRs over the study period). We used linear regression models to compare socioeconomic characteristics of patients treated at hospitals that did and did not establish TAVR programs and described the association between core-based statistical area level markers of socioeconomic status and TAVR rates. Between 2012 and 2018, 583 hospitals developed new TAVR programs, including 572 (98.1%) in metropolitan areas, and 293 (50.3%) in metropolitan areas with preexisting TAVR programs. Compared with hospitals that did not start TAVR programs, hospitals that did start TAVR programs treated fewer patients with dual eligibility for Medicaid (difference of -2.83% [95% CI, -3.78% to -1.89%], P≤0.01), higher median household incomes (difference $2447 [95% CI, $1348-$3547], P=0.03), and from areas with lower distressed communities index scores (difference -4.02 units [95% CI, -5.43 to -2.61], P≤0.01). After adjusting for the age, clinical comorbidities, race and ethnicity and socioeconomic status, areas with TAVR programs had higher rates of TAVR and TAVR rates per 100 000 Medicare beneficiaries were higher in core-based statistical areas with fewer dual eligible patients, higher median income, and lower distressed communities index scores. During the initial growth phase of TAVR programs in the United States, hospitals serving wealthier patients were more likely to start programs. This pattern of growth has led to inequities in the dispersion of TAVR, with lower rates in poorer communities.

Pre-breakdown to stable phase and origin of multiple current pulses in argon dielectric barrier discharge

We report on the results of numerical models of the (i) initial growth and (ii) steady state phases of atmospheric-pressure homogeneous dielectric barrier discharge in argon. We employ our new in-house code called PyDBD, which solves continuity equations for both particles and energy, shows exceptional stability, is accelerated by adaptive time stepping and is openly available to the scientific community. Modeling argon plasma is numerically challenging due to the lower speeds of more inertial ions compared to more commonly modeled neon and helium, but its common use for plasma jets in medicine makes its modeling compelling. PyDBD is here applied to modeling two setups: (i) the exponential growth from natural electron-ion seeds (onset phase) until saturation is reached and (ii) the multiple current pulses that naturally appear during the steady state phase. We find that the time required for the onset phase, when the plasma density grows from 109 m−3 to 1017 m−3, varies from 80 μs at 4.5 kV down to a few μs above 6.5 kV, for voltage frequency f = 80 kHz and gap width d g = 0.9 mm. At the steady state, our model reproduces two previously observed features of the current in dielectric barrier discharge reactors: (1) an oscillatory behavior associated to the capacitative character of the circuit and (2) several (N p) current pulses occurring every half sinusoidal cycle. We show that the oscillations are present during the exponential growth, while current pulses appear approaching the steady state. After each micro-discharge, the gas voltage decreases abruptly and charged particles rapidly accumulate at the dielectric boundaries, causing avalanches of charged particles near the reactor boundaries. Finally, we run a parametric study finding that N p increases linearly with voltage amplitude V amp, is inversely proportional to dielectric gap d g and decreases when voltage frequency f increases. The code developed for this publication is freely available at the address https://github.com/gabersyd/PyDBD.

93 Equivalent Effects of Growing Phase ADG and DOF at Various Placement Weights on Finishing Beef Cattle Performance Using Meta-analysis Approach

Abstract A meta-analysis approach was used to interpret effects of growing phase days and rate of gain on finishing performance at theoretically similar maturity using a dataset derived from 53 manuscripts. Growing phase feeding strategies included dry-lot feeding a high-energy finishing diet post-weaning (HG; n = 16), silage (DL-forg; n = 32) or a moderate energy diet (DL; n = 78), stocking cattle on winter wheat (WW; n = 16) or range (GR; n = 43). Independent variables of interest were initial growing phase body weight (initial BW), growing phase average daily gain (ADG), days-on-feed in growing phase (DOF), and final growing phase body weight. Data were analyzed using the PROC MIXED procedure of SAS, with treatment means weighted by experimental units (EU) per treatment. Optimal combinations of growing phase DOF and initial BW differed between models. Yet, for dressing percent (R2 = 0.39), LMA (R2 = 0.55), final finishing BW (R2 = 0.58), and HCW (R2 = 0.54) models, an 80-d growing phase for cattle starting at 240 kg resulted in greatest responses by these variables. Simulations evaluating effects of growing phase ADG on finishing performance (dressing percent; LMA; final body weight; HCW) were set equivalent to simulations evaluating the sensitivity of growing phase DOF in response to initial BW. Solving these simulations generated the initial BW at which cattle were more responsive to growing phase length (DOF) than ADG (LMAcritical point = 255 kg; DPcritical point = 242 kg; Final finishing BWcritical point = 231 kg; HCWcritical point = 233 kg). For finishing performance traits listed, each critical point represents the inflexion at which growing phase ADG exerts greatest influence on each trait modeled. Thus, for example, for cattle starting a growing phase at under 233 kg, faster growing phase ADG results in greater hot carcass weight response.

Modeling of COVID-19 propagation with compartment models

The current pandemic is a great challenge for several research areas. In addition to virology research, mathematical models and simulations can be a valuable contribution to the understanding of the dynamics of the pandemic and can give recommendations to both physicians and politicians. In this paper we give an overview about mathematical models to describe the pandemic by differential equations. As a matter of principle the historic origin of the epidemic growth models will be remembered. Moreover we discuss models for the actual pandemic of 2020/2021. This will be done based on actual data of people infected with COVID-19 from the European Centre for Disease Prevention and Control (ECDC), input parameters of mathematical models will be determined and applied. These parameters will be estimated for the UK, Italy, Spain, and Germany and used in a SIR-type model. As a basis for the model’s calibration, the initial exponential growth phase of the COVID-19 pandemic in the named countries is used. Strategies for the commencing and ending of social and economic shutdown measures are discussed. To respect heterogeneity of the people density in the different federal states of Germany diffusion effects are considered.

Study of the fracturing behaviour of an electrohydraulic shock wave in sandstone under static pressure

To understand the application of electrohydraulic shock waves (EHS) in deep rock formations, the fracturing behaviour of repetitive EHS under a static pressure environment is studied in this paper. The static pressure environment of sandstone is simulated and a load model of the transmission wave of EHS at the liquid–rock interface is proposed. Analysis of the spatial distribution, dense zone and fracture zone of microcracks shows that static pressure has a significant inhibitory effect on the formation, distribution and growth of microcracks under repetitive EHS. Compared with normal pressure, cracks in a static pressure environment are mainly concentrated around the well hole, the microcracks are denser and the extension length is shorter. At the same time, the degree of damage is established to evaluate the overall cumulative damage to the sandstone. The coupling relationship between degree of damage, static pressure, discharge energy and discharge times is fitted. The fitting model shows a behaviour of continuous decelerating growth of microcracks, which can be divided into two phases, an initial growth phase and a slow-growth phase. The increase in static pressure mainly suppresses the initial growth phase, and the discharge energy needs to be increased to promote the initial degree of damage and the rate of accumulation of microcracks in the slow-growth phase. The rate of accumulation of microcracks in the slow-growth phase can be controlled through multi-level adjustment of the discharge energy. This paper provides guidance and simulation methods for rock fracturing applications of EHS in static pressure environments.

Adsorption of organic matter on titanium surfaces with nano- and micro-scale roughness studied with the electrochemical quartz crystal microbalance dissipation technique.

Adsorption of calf serum organic matter from a phosphate-buffered solution was studied using the electrochemical quartz crystal microbalance with additional dissipation measurements. Two types of crystal surfaces were used: one rough with micrometer-range surface features and one with roughness in the low nanometer range. The results showed that the adsorption of the organic material was about 1.5 orders of magnitude larger on the rough surface and almost independent of serum concentration in the electrolyte. The adsorption rates were found to increase with increasing serum concentration. For rough crystals, the adsorption kinetics were interpreted with the Johnson-Mehl-Avrami-Kolmogorov model, indicating an initial growth phase according to the tn-law, followed by a slower growth as the nucleation sites fill up. This study suggests that specific surface sites are critical to promote adsorption of proteins on a titanium surface.

Toward usable predictive climate information at decadal timescales

Toward usable predictive climate information at decadal timescales

Biometric responses of sugarcane under high doses of vinasse

ABSTRACT Rational use of vinasse as a fertilizer in sugarcane cultivation is a good option to increase crop development and yield due to its nutritional support, properly dispose of the by-product, and reduce costs of mineral nutrition. However, in the field, controlling the amount of vinasse can be difficult, interfering in sugarcane development. In this sense, this study aimed to evaluate high doses of vinasse related to biometric responses in the initial growth phase of sugarcane plants. The experimental design was completely randomized, and the treatments consisted of five vinasse doses (0, 150, 300, 600, and 1200 m3 ha-1), with six replicates, except D0, three replicates, and one dose of mineral fertilizer with 70 kg ha-1 of N, 120 kg ha-1 of P2O5 and 90 kg ha-1 of K2O, with three replications. The biometric variables were evaluated in the following sequence: number of tillers per pot from 60 to 150 days after planting (DAP), plant height, number of green and dry leaves from 90 to 210 DAP, stem diameter, leaf area, and fresh and dry biomasses of roots and shoots at 210 DAP. Vinasse increased the biomass production through the number of tillers and the number of leaves compared to mineral fertilizer, promoting greater growth up to the dose of 600 m3 ha-1. The vinasse dose of 1200 m3 ha-1 decreased the plant height.

GREEN MANURE AND MINERAL FERTILIZATION: RESIDUAL EFFECT ON DRY MATTER PRODUCTION, NUTRIENT EXTRACTION AND NUTRIENTS RECOVERY EFFICIENCY IN TWO SUCCESIVE CROPS

<p><strong>Background.</strong> Green manures (GM) are an alternative to partially or totally replace mineral fertilizers, in successive crops, but few studies have studied the residual effect (REEF) of GM on the subsequent crops. <strong>Objective.</strong> To determine the REEF of GM (<em>Mucuna cinerea</em>, sin. <em>Stizolobium cinereum</em>) and mineral fertilization (MF) on dry matter production (DM), nutrient extraction (NEX) and soil solution (SS) characteristics in the <em>Brachiaria brizantha</em> (BB). A second objective was to determine the nutrient recovery efficiency (RE) in two successive crops of broccoli and BB. <strong>Methodology.</strong> A single application of GM snd MF was done on broccoli crop, in pots and greenhouse conditions. The treatments were: 1) unfertilized plants (Control). 2) 200% of the recommended dose for broccoli, applied exclusively through MF (MF200). 3) GM at 10 t ha<sup>-1</sup> (GM10). 4) The same dose of N, P, K, Ca, Mg, and S applied through GM10 was applied through MF (MF=GM10). 5) GM10 + MF to supply the same dose of N, P, K, Ca, Mg, and S supplied with MF200 (GM10+MF). After broccoli harvest, the BB was planted in the same pots, without additional fertilization. <strong>Results.</strong> In BB, greater REEF on DM, NEX (N, P, K, Ca, Mg and S), electrical conductivity and nutrient concentration (N, K, Ca, Mg and S) in SS, was detected with GM10 and GM10+MF. Considering both crops, greater DM and NEX were obtained with MF200 and GM10+MF. Higher RE of P and S was obtained with GM10, while, higher RE of K and Ca was obtained with the MF=GM10. <strong>Implications.</strong> The study shows that the efficiency of nutrients applied through GM at 10 t ha<sup>-1</sup>, combined with low doses of mineral fertilization, increases in successive crops. <strong>Conclusion.</strong> The REEF on the DM and nutrient extraction of the BB change depending on the fertilizer type and dose used. The REEF on the SS characteristics is only detected in the initial growth phase of the BB. In successive crops, the proportion of DM produced and the amount of nutrients extracted changes depending on the species used. To obtain a similar nutrient recovery between GM and MF is necessary to consider the DM of more of one crop.</p>

English

Water stress, caused by excess or lower of water, can negatively affect leaf metabolism and seedling growth and prevent it from developing its maximum genetic potential. In this sense, it is necessary to use as that can mitigate these deleterious effects on plants at their initial phase of growth. The aim of this work was to evaluate the effect of hydrogel in the mitigation of water stress (deficit and flooding) on photosynthetic metabolism and growth characteristics of C. odorata seedlings, and also evaluate their recovery potential after the resumption of irrigation. The characteristics of photosynthetic metabolism, growth and quality of C. odorata seedlings showed a reduction caused by water fluctuations, indicating sensitivity to these conditions, although photosynthesis photochemistry was affected to a lower extent. The addition of the hydro-retainer polymer contributed little to the biochemical and photochemical indicators of photosynthesis and seedling quality, a fact that directs us to reject our hypothesis that its use promotes mitigation of damage to the photosynthetic apparatus and to the growth. Cedrela odorata is sensitive to water variations in the soil, but recovers the photosynthetic metabolism and quality of the seedlings once the stressful water condition is suspended. The application of the hydro-retainer polymer mitigated, but the seedlings recovered regardless of their presence. © 2021 Friends Science Publishers