Reaction of micromycetes of leached chernozem on the application of different forms of nitrogen fertilizers

Международная научно-практическая конференция «РАЦИОНАЛЬНОЕ ИСПОЛЬЗОВАНИЕ ПРИРОДНЫХ РЕСУРСОВ В АГРОЦЕНОЗАХ» ◽

10.33952/2542-0720-15.05.2020.34 ◽

2020 ◽

Author(s):

L.D. Stakhurlova ◽

◽

I.D. Svistova ◽

Keyword(s):

Stress Reaction ◽

Nitrogen Fertilizers ◽

Species Structure ◽

Typical Species ◽

Phytotoxic Activity ◽

Aspergillus Ustus ◽

Leached Chernozem ◽

Native Soil ◽

Adaptive Zone

Application of nitrogen fertilizers did not significantly affect the number of micromycetes. The restructuring of the species structure of the mycobiome did not exceed the adaptive zone of “stress” – a change in the frequency of occurrence of typical species. Typical types of leached chernozem micromycetes include deuteromycetes of the genera Aspergillus, Penicillium, Trichoderma, Gliocladium, Humicola, Fusarium, zygomycetes (genus Rhizopus), ascomycetes (genera Thalaromyces, Chaetomium). On average, the density of dominant species of micromycetes increased by 20 %, which indicates the development of the “dominance concentration” of typical species and a decrease in the share of rare and random species of fungi in the mycocomplex. In the experiment variants, the density of Penicillium daleae, P. funiculosum, Fusarium solani, and Aspergillus ustus species increased compared to control. These types of micromycetes are toxigenic and synthesize broad-spectrum mycotoxins (fungicidal, antibiotic, and phytotoxic). As a result, the phytotoxic activity of the soil increased to 7 and 20 % (native soil) and to 19-34 % (initiated microbial community). More pronounced changes were observed in the variant with ammonium sulfate. Thus, nitrogen fertilizers at a dose of N90 cause a “stress” reaction of the mycobiome, an increase in the share of toxigenic species and phytotoxic activity of leached chernozem. With long-term systematic use of nitrogen fertilizers, even in medium doses, it is possible to reduce the potential fertility of chernozems.

Download Full-text

Sustaining Rice Production through Biofertilization with N2-Fixing Cyanobacteria

Applied Sciences ◽

10.3390/app11104628 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4628

Author(s):

Macarena Iniesta-Pallarés ◽

Consolación Álvarez ◽

Francisco M. Gordillo-Cantón ◽

Carmen Ramírez-Moncayo ◽

Pilar Alves-Martínez ◽

...

Keyword(s):

Agricultural Practices ◽

Vital Role ◽

Rice Production ◽

Point Of View ◽

Paddy Fields ◽

Nitrogen Fertilizers ◽

Trophic Chain ◽

Agricultural Practice ◽

Biotechnological Potential

Current agricultural productivity depends on an exogenous nutrient supply to crops. This is of special relevance in cereal production, a fundamental part of the trophic chain that plays a vital role in the human diet. However, our agricultural practices entail highly detrimental side-effects from an environmental point of view. Long-term nitrogen fertilization in croplands results in degradation of soil, water, and air quality, producing eutrophication and subsequently contributing to global warming. In accordance with this, there is a biotechnological interest in using nitrogen-fixing microorganisms to enhance crop growth without adding chemically synthesized nitrogen fertilizers. This is particularly beneficial in paddy fields, where about 60% of the synthetic fertilizer that has been applied is dissolved in the water and washed away. In these agricultural systems, N2-fixing cyanobacteria show a promising biotechnological potential as biofertilizers, improving soil fertility while reducing the environmental impact of the agricultural practice. In the current study, Andalusian paddy fields have been explored to isolate N2-fixing cyanobacteria. These endogenous microorganisms have been subsequently re-introduced in a field trial in order to enhance rice production. Our results provide valuable insights regarding the use of an alternative natural source of nitrogen for rice production.

Download Full-text

The phosphoproteome of rice leaves responds to water and nitrogen supply

10.1101/2021.03.15.435047 ◽

2021 ◽

Author(s):

Sara Hamzelou ◽

Vanessa J. Melino ◽

Darren C. Plett ◽

Karthik Shantharam Kamath ◽

Arkadiusz Nawrocki ◽

...

Keyword(s):

Prolonged Exposure ◽

Water Channel ◽

Nitrogen Supply ◽

Nitrogen Fertilizers ◽

Label Free ◽

Limited Information ◽

Irrigated Rice ◽

Post Translational Modifications ◽

Growth Adaptation

The scarcity of freshwater is an increasing concern in flood-irrigated rice, whilst excessive use of nitrogen fertilizers is both costly and contributes to environmental pollution. To co-ordinate growth adaptation under prolonged exposure to limited water or excess nitrogen supply, plants have processes for signalling and regulation of metabolic processes. There is limited information on the involvement of one of the most important post-translational modifications (PTMs), protein phosphorylation, on plant adaptation to long-term changes in resource supply. Oryza sativa cv. Nipponbare was grown under two regimes of nitrogen from the time of germination to final harvest. Twenty-five days after germination, water was withheld from half the pots in each nitrogen treatment and low water supply continued for an additional 26 days, while the remaining pots were well watered. Leaves from all four groups of plants were harvested after 51 days in order to test whether phosphorylation of leaf proteins responded to prior abiotic events. The dominant impact of these resources is exerted in leaves, where PTMs have been predicted to occur. Proteins were extracted and phosphopeptides were analysed by nanoLC-MS/MS analysis, coupled with label-free quantitation. Water and nitrogen regimes triggered extensive changes in phosphorylation of proteins involved in membrane transport, such as the aquaporin OsPIP2-6, a water channel protein. Our study reveals phosphorylation of several peptides belonging to proteins involved in RNA-processing and carbohydrate metabolism, suggesting that phosphorylation events regulate the signalling cascades that are required to optimize plant response to resource supply.

Download Full-text

Type of organic fertilizer rather than organic amendment per se increases abundance of soil biota

PeerJ ◽

10.7717/peerj.11204 ◽

2021 ◽

Vol 9 ◽

pp. e11204

Author(s):

Maria Viketoft ◽

Laura G.A. Riggi ◽

Riccardo Bommarco ◽

Sara Hallin ◽

Astrid R. Taylor

Keyword(s):

Organic Matter ◽

Organic Amendments ◽

Trophic Levels ◽

Soil Biota ◽

Organic Fertilizers ◽

Nitrogen Fertilizers ◽

Mineral Fertilizers ◽

Soil Organisms ◽

Wide Range

Addition of organic amendments is a commonly used practice to offset potential loss of soil organic matter from agricultural soils. The aim of the present study was to examine how long-term addition of organic matter affects the abundance of different soil biota across trophic levels and the role that the quality of the organic amendments plays. Here we used a 17-year-old fertilization experiment to investigate soil biota responses to four different organic fertilizers, compared with two mineral nitrogen fertilizers and no fertilization, where the organic fertilizers had similar carbon content but varied in their carbon to nitrogen ratios. We collected soil samples and measured a wide range of organisms belonging to different functional groups and trophic levels of the soil food web. Long-term addition of organic and mineral fertilizers had beneficial effects on the abundances of most soil organisms compared with unfertilized soil, but the responses differed between soil biota. The organic fertilizers generally enhanced bacteria and earthworms. Fungi and nematodes responded positively to certain mineral and organic fertilizers, indicating that multiple factors influenced by the fertilization may affect these heterogeneous groups. Springtails and mites were less affected by fertilization than the other groups, as they were present at relatively high abundances even in the unfertilized treatment. However, soil pH had a great influence on springtail abundance. In summary, the specific fertilizer was more important in determining the numerical and compositional responses of soil biota than whether it was mineral or organic. Overall, biennial organic amendments emerge as insufficient, by themselves, to promote soil organisms in the long run, and would need to be added annually or combined with other practices affecting soil quality, such as no or reduced tillage and other crop rotations, to have a beneficial effect.

Download Full-text

Significance of the Cerebrovascular Effects of Immobilization Stress in the Rabbit

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/jcbfm.1984.58 ◽

1984 ◽

Vol 4 (3) ◽

pp. 397-406 ◽

Cited By ~ 8

Author(s):

Pierre Lacombe ◽

Jacques Seylaz

Keyword(s):

Blood Pressure ◽

Arterial Blood Pressure ◽

Immobilization Stress ◽

Sampling Technique ◽

Stress Reaction ◽

Acute Hypertension ◽

Cerebrovascular Autoregulation ◽

Arterial Blood ◽

Systemic Factors

The question of the significance of the cerebrovascular effects of stressful situations in animals is still controversial. In the present article, an experimental model of immobilization stress in the rabbit is described, and its specificity in relation to arterial blood pressure and PaCO2 is investigated. CBF was measured with the multiregional tissue sampling technique using [14C]-ethanol as tracer. After dissipation of althesin anesthesia, the stress reaction was elicited by tactile abdominal stimuli. The response was evidenced by an instantaneous acute hypertension (+ 33.8% during the CBF measurement period). Within the first minute of the reaction, the CBF was significantly increased in all nine structures studied by 39% (caudate nucleus) to 82% (parietotemporal cortex). The study of the influence of arterial blood pressure and the PaCO2 on CBF showed that cerebrovascular autoregulation and CO2 sensitivity were differently affected in the various structures during the stress reaction. However, the stress response of the brain circulation could not be entirely ascribed to one or both of these two systemic factors, thus suggesting the contribution of a local intrinsic activation. The model presented here could be useful for long-term studies of cerebrovascular repercussions of repeated acute hypertensions of a stressful nature.

Download Full-text

Evaluation and indirect estimation of nitrate losses from the agricultural microbasin Rybárik

Biologia ◽

10.2478/s11756-007-0113-5 ◽

2007 ◽

Vol 62 (5) ◽

Cited By ~ 1

Author(s):

Michal Sebíň ◽

Pavla Pekárová ◽

Pavol Miklánek

Keyword(s):

Nitrate Concentration ◽

Empirical Relation ◽

Annual Runoff ◽

Nitrogen Fertilizers ◽

Nitrate Transport ◽

Nitrate Losses ◽

Long Term Trends ◽

Academy Of Sciences ◽

Annual Amount

AbstractThe long-term trends of mean monthly nitrate concentrations in stream and drainage runoff were evaluated in the experimental microbasin Rybárik (0.119 km2) at the Institute of Hydrology, Slovak Academy of Sciences, during the period 1987–2005. The results of analyses indicate a decreasing trend of nitrate concentration after the year 1989, but with relatively high losses in some years and relatively low losses in other years. This decreasing trend is mainly caused by a decrease in the use of nitrogen fertilizers. The nitrate concentration in surface runoff strongly correlates with runoff and fertilization. Based on measured data, an empirical relation was found describing the dependence of annual nitrate transport in the stream on annual runoff depth and on the annual amount of applied nitrogen fertilizers.

Download Full-text