The role of various ameliorants on geochemical arsenic distribution and CO2-carbon efflux under paddy soil conditions

2022 ◽  
Author(s):  
Muhammad Mahroz Hussain ◽  
Irshad Bibi ◽  
Fawad Ali ◽  
Zulfiqar Ahmad Saqib ◽  
Muhammad Shahid ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Soil Conditions ◽  
Arsenic Distribution

scholarly journals Richness of Rhizosphere Organisms Affects Plant P Nutrition According to P Source and Mobility

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Jean Trap ◽  
Patricia Mahafaka Ranoarisoa ◽  
Usman Irshad ◽  
Claude Plassard
Keyword(s):  
Careful Consideration ◽  
Soil Conditions ◽  
Organic P ◽  
P Nutrition ◽  
Soil P ◽  
P Acquisition ◽  
Complex Interactions ◽  
Experimental Trials ◽  
The Relationship

Plants evolve complex interactions with diverse soil mutualist organisms to enhance P mobilization from the soil. These strategies are particularly important when P is poorly available. It is still unclear how the soil P source (e.g., mineral P versus recalcitrant organic P) and its mobility in the soil (high or low) affect soil mutualist biological (ectomycorrhizal fungi, bacteria and bacterial-feeding nematodes) richness—plant P acquisition relationships. Using a set of six microcosm experiments conducted in growth chamber across contrasting P situations, we tested the hypothesis that the relationship between the increasing addition of soil mutualist organisms in the rhizosphere of the plant and plant P acquisition depends on P source and mobility. The highest correlation (R2 = 0.70) between plant P acquisition with soil rhizosphere biological richness was found in a high P-sorbing soil amended with an organic P source. In the five other situations, the relationships became significant either in soil conditions, with or without mineral P addition, or when the P source was supplied as organic P in the absence of soil, although with a low correlation coefficient (0.09 < R2 < 0.15). We thus encourage the systematic and careful consideration of the form and mobility of P in the experimental trials that aim to assess the role of biological complexity on plant P nutrition.

Epidemiological problems. Soil and epidemics. Experimental evidence supporting a causal relationship between soil conditions and the onset of epidemics

1935 ◽  
Vol 31 (3-4) ◽  
pp. 533-533
Author(s):  
Н. Lotze
Keyword(s):  
Experimental Evidence ◽  
Causal Relationship ◽  
Soil Conditions

A. advocates the theory of Pettenkofer about the role of soil in the emergence of epidemics.

Pesticide and element release from a paddy soil in central Vietnam: Role of DOC and oxidation state during flooding

Geoderma ◽  
2018 ◽  
Vol 310 ◽  
pp. 209-217 ◽  
Author(s):  
Ha Thu Trinh ◽  
Hanh Thi Duong ◽  
Giang Truong Le ◽  
Helle Marcussen ◽  
Bjarne W. Strobel
Keyword(s):  
Oxidation State ◽  
Paddy Soil ◽  
Central Vietnam

Impact and uncertainty of climate projections on Alpine catchments using high-resolution models

2021 ◽  
Author(s):  
Jorge Sebastian Moraga ◽  
Nadav Peleg ◽  
Simone Fatichi ◽  
Peter Molnar ◽  
Paolo Burlando
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Climate Variability ◽  
Soil Conditions ◽  
Internal Climate Variability ◽  
Mountainous Catchments ◽  
Precipitation Decrease ◽  
Alpine Catchments ◽  
Impacts Of Climate Change

&lt;p&gt;Hydrological processes in mountainous catchments will be subject to climate change on all scales, and their response is expected to vary considerably in space. Typical hydrological studies, which use coarse climate data inputs obtained from General Circulation Models (GCM) and Regional Climate Models (RCM), focus mostly on statistics at the outlet of the catchments, overlooking the effects within the catchments. Furthermore, the role of uncertainty, especially originated from natural climate variability, is rarely analyzed. In this work, we quantified the impacts of climate change on hydrological components and determined the sources of uncertainties in the projections for two mostly natural Swiss alpine catchments: Kleine Emme and Thur. Using a two-dimensional weather generator, AWE-GEN-2d, and based on nine different GCM-RCM model chains, we generated high-resolution (2 km, 1 hour) ensembles of gridded climate inputs until the end of the 21&lt;sup&gt;st&lt;/sup&gt; century. The simulated variables were subsequently used as inputs into the fully distributed hydrological model Topkapi-ETH to estimate the changes in hydrological statistics at 100-m and hourly resolutions. Increased temperatures (by 4&amp;#176;C, on average) and changes in precipitation (decrease over high elevations by up to 10%, and increase at the lower elevation by up to 15%) results in increased evapotranspiration rates in the order of 10%, up to a 50% snowmelt, and drier soil conditions. These changes translate into important shifts in streamflow seasonality at the outlet of the catchments, with a significant increase during the winter months (up to 40%) and a reduction during the summer (up to 30%). Analysis at the sub-catchment scale reveals elevation-dependent hydrological responses: mean annual streamflow, as well as high and low flow extremes, are projected to decrease in the uppermost sub-catchments and increase in the lower ones. Furthermore, we computed the uncertainty of the estimations and compared them to the magnitude of the change signal. Although the signal-to-noise-ratio of extreme streamflow for most sub-catchments is low (below 0.5) there is a clear elevation dependency. In every case, internal climate variability (as opposed to climate model uncertainty) explains most of the uncertainty, averaging 85% for maximum and minimum flows, and 60% for mean flows. The results highlight the importance of modelling the distributed impacts of climate change on mountainous catchments, and of taking into account the role of internal climate variability in hydrological projections.&lt;/p&gt;

scholarly journals Modelling Methane and Nitrous Oxide Emissions from Rice Paddy Wetlands in India Using Artificial Neural Networks (ANNs)

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2169 ◽  
Author(s):  
Tabassum Abbasi ◽  
Tasneem Abbasi ◽  
Chirchom Luithui ◽  
Shahid Abbas Abbasi
Keyword(s):  
Nitrous Oxide ◽  
Paddy Fields ◽  
Anthropogenic Sources ◽  
Nitrous Oxide Emissions ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Ch4 Emissions ◽  
Artificial Neural ◽  
Ch4 And N2o

Paddy fields, which are shallow man-made wetlands, are estimated to be responsible for ~11% of the total methane emissions attributed to anthropogenic sources. The role of water use in driving these emissions, and the apportioning of the emissions to individual countries engaged in paddy cultivation, are aspects that have been mired in controversy and disagreement. This is largely due to the fact that methane (CH4) emissions not only change with the cultivar type but also regions, climate, soil type, soil conditions, manner of irrigation, type and quantity of fertilizer added—to name a few. The factors which can influence these aspects also encompass a wide range, and have origins in causes which can be physical, chemical, biological, and combinations of these. Exceedingly complex feedback mechanisms, exerting different magnitudes and types of influences on CH4 emissions under different conditions, are operative. Similar is the case of nitrous oxide (N2O); indeed, the present level of understanding of the factors which influence the quantum of its emission is still more patchy. This makes it difficult to even understand precisely the role of the myriad factors, less so model them. The challenge is made even more daunting by the fact that accurate and precise data on most of these aspects is lacking. This makes it nearly impossible to develop analytical models linking causes with effects vis a vis CH4 and N2O emissions from paddy fields. For situations like this the bioinspired artificial intelligence technique of artificial neural network (ANN), which can model a phenomenon on the basis of past data and without the explicit understanding of the mechanism phenomena, may prove useful. However, no such model for CH4 or N2O has been developed so far. Hence the present work was undertaken. It describes ANN-based models developed by us to predict CH4 and N2O emissions using soil characteristics, fertilizer inputs, and rice cultivar yield as inputs. Upon testing the predictive ability of the models with sets of data not used in model development, it was seen that there was excellent agreement between model forecasts and experimental findings, leading to correlations coefficients of 0.991 and 0.96, and root mean square error (RMSE) of 11.17 and 261.3, respectively, for CH4 and N2O emissions. Thus, the models can be used to estimate CH4 and N2O emissions from all those continuously flooded paddy wetlands for which data on total organic carbon, soil electrical conductivity, applied nitrogen, phosphorous and potassium, NPK, and grain yield is available.

Dynamic behaviour of an open lugged wheel under paddy soil conditions

1993 ◽  
Vol 30 (3) ◽  
pp. 191-203 ◽  
Author(s):  
X.L. Wang ◽  
M. Yamazaki ◽  
T. Tanaka
Keyword(s):  
Paddy Soil ◽  
Dynamic Behaviour ◽  
Soil Conditions

scholarly journals Dynamic release and transformation of metallic copper colloids in flooded paddy soil: Role of soil reducible sulfate and temperature

2021 ◽  
Vol 402 ◽  
pp. 123462
Author(s):  
Hang Xu ◽  
Bing Xia ◽  
Erkai He ◽  
Rongliang Qiu ◽  
Willie J.G.M. Peijnenburg ◽  
...  
Keyword(s):  
Paddy Soil ◽  
Metallic Copper ◽  
Flooded Paddy Soil

Earthworm bioturbation stabilizes carbon in non-flooded paddy soil at the risk of increasing methane emissions under wet soil conditions

2015 ◽  
Vol 91 ◽  
pp. 127-132 ◽  
Author(s):  
Katharina John ◽  
Frank Jauker ◽  
Juergen Marxsen ◽  
Andrei S. Zaitsev ◽  
Volkmar Wolters
Keyword(s):  
Paddy Soil ◽  
Methane Emissions ◽  
Soil Conditions ◽  
Flooded Paddy Soil

A study of heterokaryosis and its influence on virulence in Fusarium oxysporum lycopersici

1979 ◽  
Vol 57 (5) ◽  
pp. 548-555 ◽  
Author(s):  
Gurmel S. Sldhu ◽  
John M. Webster
Keyword(s):  
Amino Acid ◽  
Fusarium Oxysporum ◽  
Ultraviolet Irradiation ◽  
Single Step ◽  
Natural Variability ◽  
Soil Conditions ◽  
Tomato Cultivars ◽  
Fungi Imperfecti

Single-step amino acid auxotrophs were obtained by ultraviolet irradiation of microconidia from races I and 2 of Fusarium oxysporum lycopersici. Intrarace and interrace combinations were made between the mutants to synthesize heterokaryons. After appropriate tests, 13 heterokaryons were selected for analyses of nuclear ratios and virulence. Results indicate that nuclear ratios of intrarace heterokaryons were more balanced than those of interrace heterokaryons. This may be due to incompatibility factors. Tests on four tomato cultivars indicate that heterokaryons rarely show an increase in virulence. There was limited occurrence and low survival of heterokaryons under soil conditions. The findings are discussed in light of the role of heterokaryosis in natural variability and virulence of Fungi Imperfecti.

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