scholarly journals The Synergistic Effects of Humic Substances and Biofertilizers on Plant Development and Microbial Activity: A Review

Author(s):  
Jose Franco Da Cunha Leme Filho ◽  
Wade E. Thomason ◽  
Gregory K. Evanylo ◽  
Xunzhong Zhang ◽  
Michael S. Strickland ◽  
...  

Agroecosystem and ecological cycling loops are open when considering the reutilization of inputs applied in farming areas. Non-renewable resources have been transformed or relocated from the air, water and land into the system and are flowing out as wastes rather than reusable, recyclable resources. This current environmental situation is promoting the development of methods able to optimize nutrient cycling, minimize use of external inputs, and maximize input use efficiency. Some humic products are derived from lignin found in wheat straw and biofertilizers as compost and manure teas can be made using residues. Also, these biostimulants might decrease the necessity of synthetic inputs. This review strives to enhance our understanding of the conjunctive use of humic substances (HS) and biofertilizers. The biostimulant effects of each of these compounds are shown in the literature. Thus, our review question is whether the combined application of HS and biofertilizers can promote synergy between both compounds and potentially more efficacy. The effects promoted by using HS plus biofertilizers on plants and microorganisms are very interconnected, so sometimes these effects can be confounded. For instance, the root elongation promoted by HS might increase hyphal fungi colonization. Therefore, this review as divided in three sections: Responses of plants, fungi and bacteria. The findings indicate that the source and application rate of HS will have a strong impact on whether plant growth and microbial activity significantly improved. The microbial species and plant type also influence the response to HS. The prospects of the conjunctive use of and biofertilizers to stimulate plant development and microbial activity in agricultural systems are theoretically substantial when considering the total number of studies included in this review.

2021 ◽  
Vol 22 (5) ◽  
pp. 2771
Author(s):  
Anna Richter ◽  
Elisabeth Fischer ◽  
Clemens Holz ◽  
Julia Schulze ◽  
Sandra Lange ◽  
...  

Aberrant PI3K/AKT signaling is a hallmark of acute B-lymphoblastic leukemia (B-ALL) resulting in increased tumor cell proliferation and apoptosis deficiency. While previous AKT inhibitors struggled with selectivity, MK-2206 promises meticulous pan-AKT targeting with proven anti-tumor activity. We herein, characterize the effect of MK-2206 on B-ALL cell lines and primary samples and investigate potential synergistic effects with BCL-2 inhibitor venetoclax to overcome limitations in apoptosis induction. MK-2206 incubation reduced AKT phosphorylation and influenced downstream signaling activity. Interestingly, after MK-2206 mono application tumor cell proliferation and metabolic activity were diminished significantly independently of basal AKT phosphorylation. Morphological changes but no induction of apoptosis was detected in the observed cell lines. In contrast, primary samples cultivated in a protective microenvironment showed a decrease in vital cells. Combined MK-2206 and venetoclax incubation resulted in partially synergistic anti-proliferative effects independently of application sequence in SEM and RS4;11 cell lines. Venetoclax-mediated apoptosis was not intensified by addition of MK-2206. Functional assessment of BCL-2 inhibition via Bax translocation assay revealed slightly increased pro-apoptotic signaling after combined MK-2206 and venetoclax incubation. In summary, we demonstrate that the pan-AKT inhibitor MK-2206 potently blocks B-ALL cell proliferation and for the first time characterize the synergistic effect of combined MK-2206 and venetoclax treatment in B-ALL.


2012 ◽  
Vol 358 (1-2) ◽  
pp. 213-223 ◽  
Author(s):  
Ana Lázaro-Nogal ◽  
Silvia Matesanz ◽  
Teresa E. Gimeno ◽  
Adrián Escudero ◽  
Fernando Valladares

2017 ◽  
Vol 6 (1) ◽  
pp. 25-29 ◽  
Author(s):  
Yuchi Jia ◽  
Xiaomei Wu

Abstract Objective We aimed to evaluate the combined antibacterial effects of allicin in combination with levofloxacin and ceftriaxone on Shigella isolated from the intestinal tract in vitro. Materials and Methods Using a checkerboard design, broth microdilution assay was used to test the effects of the compounds on the organism. We also determined the MIC of the two groups of antibacterial drugs against 30 strains of Shigella and calculated the fractional inhibitory concentration (FIC) index, to judge the combination effect. Result After the combined application of allicin and ceftriaxone the MIC decreased significantly. Distribution of the FIC index was as follows: FIC ≤0.5, accounting for 10%; 0.5< FIC ≤1.0, accounting for 60%; 1 < FIC ≤2, accounting for 30%; FIC >2, percentage is zero. After combined application of allicin and levofloxacin, distribution of FIC index was as follows: FIC≤0.5, ratio is zero; 0.5< FIC ≤1, accounting for 56.7%; 1 < FIC ≤2, accounting for 43.3%; FIC >2, ratio is zero. Conclusion After the combined use of ceftriaxone, levofloxacin, and allicin, most of the tests showed synergistic effects and additive effects on Shigella, while some of them showed no correlation and no antagonistic effect.


2012 ◽  
Vol 25 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Juliana Vanir De Souza Carvalho ◽  
Eduardo De Sá Mendonça ◽  
Newton La Scala ◽  
César Reis ◽  
Efrain Lázaro Reis ◽  
...  

AbstractPolar Regions are the most important soil carbon reservoirs on Earth. Monitoring soil carbon storage in a changing global climate context may indicate possible effects of climate change on terrestrial environments. In this regard, we need to understand the dynamics of soil organic matter in relation to its chemical characteristics. We evaluated the influence of chemical characteristics of humic substances on the process of soil organic matter mineralization in selected Maritime Antarctic soils. A laboratory assay was carried out with soils from five locations from King George Island. We determined the contents of total organic carbon, oxidizable carbon fractions of soil organic matter, and humic substances. Two in situ field experiments were carried out during two summers, in order to evaluate the CO2-C emissions in relation to soil temperature variations. The overall low amounts of soil organic matter in Maritime Antarctic soils have a low humification degree and reduced microbial activity. CO2-C emissions showed significant exponential relationship with temperature, suggesting a sharp increase in CO2-C emissions with a warming scenario, and Q10 values (the percentage increase in emission for a 10°C increase in soil temperature) were higher than values reported from elsewhere. The sensitivity of the CO2-C emission in relation to temperature was significantly correlated with the humification degree of soil organic matter and microbial activity for Antarctic soils.


2021 ◽  
Author(s):  
Chunyu Tang ◽  
Yuelei Li ◽  
Song Jingpeng ◽  
Markus Antonietti ◽  
Fan Yang

Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1612 ◽  
Author(s):  
Nikolett Uzinger ◽  
Tünde Takács ◽  
Tibor Szili-Kovács ◽  
László Radimszky ◽  
Anna Füzy ◽  
...  

The short-term effects of processed waste materials: sewage sludge compost (up to 0.5%), biochar made of paper sludge and grain husk (BC) (up to 2%) combined with plant growth-promoting rhizobacterial (PGPR) inoculum, on the fertility of acidic sandy soil at 65% of field capacity were tested in a pot experiment in separate and combined treatments. The soil pH, organic matter content, total and plant-available nutrients, substrate-induced respiration, arbuscular mycorrhizal fungal (AMF) root colonisation parameters and maize (Zea mays L.) biomass were investigated in experiments lasting two months. The positive priming (21% organic matter loss) induced by BC alone was not observed after combined application. The combination of compost and PGPR with 1.5% BC resulted in 35% higher P and K availability due to greater microbial activity compared to BC alone. Only compost applied alone at 0.5% gave a 2.7 times increase in maize biomass. The highest microbial activity and lowest AMF colonisation were found in combined treatments. In the short term the combined application of BC, compost and PGPR did not result in higher fertility on the investigated soil. Further research is needed with a wider range of combined treatments on acidic sandy soil for better understanding of the process.


2018 ◽  
Vol 34 (11) ◽  
pp. 1303-1308 ◽  
Author(s):  
Apichaya ANEKSAMPANT ◽  
Atsushi TANAKA ◽  
Xuefei TU ◽  
Hisanori IWAI ◽  
Mitsuo YAMAMOTO ◽  
...  

2020 ◽  
Vol 71 (3) ◽  
pp. 294 ◽  
Author(s):  
M. W. Canto ◽  
E. J. Pancera ◽  
A. Barth Neto ◽  
C. Bremm ◽  
P. U. Vier ◽  
...  

The effects of nitrogen (N) fertiliser rate and irrigation on seed yield and its components were evaluated for signal grass (Urochloa decumbens (Stapf) R.D. Webster; syn. of Brachiaria decumbens Stapf) cv. Basilisk in a field experiment in Umuarama, Paraná, Brazil. Two water regimes (irrigated and non-irrigated) and four nitrogen (N) fertiliser rates (0, 25, 50 and 75 kg ha–1) were applied to perennial signal grass crops in a split-plot randomised complete block design with three replications. In two consecutive harvests, favourable rainfall resulted in irrigation having limited influence on most measurements, and the combined application of irrigation and N fertiliser did not improve seed yield. Compared with the nil N, the highest N application rate significantly increased seed yield for the first crop (266 vs 498 kg ha–1) and the second crop (104 vs 286 kg ha–1). Nitrogen fertilisation significantly increased number of seed per area, reproductive tiller density and plant biomass at harvest for the first and second crops. Harvest index, 1000-seed weight, reproductive tiller weight, number of spikelets per panicle and number of seeds per panicle were unaffected by N rate. Harvest index ranged from 1.10% to 3.63% and 1000-seed weight from 2.15 to 3.36 g. There were no treatment effects on number of days to flowering or anthesis. Fertilisation with 75 kg N ha–1 for the first crop and 50–75 kg N ha–1 for the second crop maximised signal grass seed yield.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1143D-1144
Author(s):  
Mehar Asif ◽  
Prabodh Trivedi ◽  
Theophanes Solomos ◽  
Autar Mattoo

We have studied the effects of MCP and low O2, applied singly and in combination, on apple fruit ripening at 1, 7, and 18 °C. The single application of 2 ppm MCP is more effective in delaying the onset of the C2H4 climacteric than is 1% O2. However, the combined application has a much larger effect than the single applications of either MCP or 1% O2. For instance, at 7 °C, the onset of the C2H4 climacteric occurs at 15, 50, and 90–95 days for the controls, 1% O2 and 2 ppm MCP, respectively, whereas the combined application of 2 ppm MCP and 1% O2 suppressed the initiation of the C2H4 climacteric for 200 days, the duration of the experiment. The retardation of the climacteric onset by the treatments is associated with the suppression of ACC-synthase (ACS1) and the putative receptor ERS1. The accumulation of their transcripts is critically dependent on the rate of C2H4 evolution. As expected, the combined application of MCP and 1% O2 completely suppressed the expression of both genes. Yet when the fruits were transferred to 18 °C in air, they ripened normally. A similar pattern of inhibition in response to the above treatments was also observed with a C2H4-dependent MAPK. The expression of ETR1, ETR2 and ACC-oxidase was not affected by the treatments. The nature of this strong effect of the combined application of MCP and low O2 is not clear. It should be pointed out that MCP does not inhibit the induction of hypoxic proteins such as ADH.


Author(s):  
Subhradip Bhattacharjee ◽  
V. M. Bhale ◽  
Pramod Kumar ◽  
Sheilendra Kumar ◽  
Deepak Kumar ◽  
...  

Aims: This field experiment was conducted to compare the combined application of different rates of potassium and zinc application against the standard farmers practised application rate based on dry matter distribution, net photosynthesis, transpiration rate, sub stomatal C02 concentration, stomatal conductance, grain yield and quality attributes (protein and carbohydrate content and yield).  Place and Duration of Study: This short-term field trial was conducted on the Agronomy Research Farm of Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, Maharashtra, India on the Kharif (Post monsoon) season of 2016. Methodology: The experiment was conducted in Factorial Randomized Block Design (FRBD) with two factors i.e., potassium and zinc, each having three levels. The experiment was replicated thrice. The three potassium levels were 30, 60 and 90 kg K2O ha-1 while the zinc was applied 20, 30 and 40 kg ZnSO4.7H2O ha-1 as three distinctive levels.  A short duration dwarf maize cultivar Ravi-81 was used for the experiment. Results: Perusal of experiment results confirmed that potassium and zinc have positive interaction even in short duration crop under dryland condition. The higher dry matter accumulation, crop growth rate, photosynthetic attributes, yield, protein content, protein yield, and carbohydrate yield has been recorded with the application of potassium at a rate of 60 kg K2O ha-1 along with zinc application of 30 kg ZnSO4.7H2O ha-1 which has been found to be statistically superior over farmers adopted practice (30 kg K2O ha-1 along with zinc application of 20 kg ZnSO4.7H2O ha-1). Conclusion: Combined application of potassium and zinc has positive interaction on each other, and the increased rate is needed to meet the demand for short duration high yielding maize crop for enhanced growth, yield and quality attributes.


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