scholarly journals Factors affecting nitrogenase activity (C2H2 reduction) associated with sorghum and millet estimated using the soil core assay

1983 ◽  
Vol 29 (8) ◽  
pp. 1063-1069 ◽  
Author(s):  
S. P. Wani ◽  
P. J. Dart ◽  
M. N. Upadhyaya
Keyword(s):  
Soil Moisture ◽  
Seasonal Variation ◽  
Moisture Content ◽  
Soil Temperature ◽  
Diurnal Variation ◽  
Host Plant ◽  
Soil Moisture Content ◽  
Nitrogenase Activity ◽  
Soil Core ◽  
Factors Affecting

Factors affecting nitrogenase activity associated with sorghum and millet roots have been studied. Plants grown in iron cores in the field and then assayed had significantly higher activity than plants cored at the time of assay. Mechanical disturbance during transportation of the cores reduced the activity significantly. Any delay between cutting off the plant top and injecting C2H2 gas led to a reduction in the level of nitrogenase activity determined. Diurnal variation in nitrogenase activity was noted but was not correlated with soil temperature. Most activity occurred at the end of the photoperiod. Seasonal variation in nitrogenase activity of plants was observed and was correlated with the ontogenetic development of the host plant, being most at flowering. A low but significant correlation existed between soil moisture content and nitrogenase activity associated with the plant.

scholarly journals Simulations and Experiments of the Soil Temperature Distribution after 2.45-GHz Short-Time Term Microwave Treatment

Agriculture ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 933
Author(s):  
Xiaohe Sun ◽  
Changyuan Zhai ◽  
Shuo Yang ◽  
Haolin Ma ◽  
Chunjiang Zhao
Keyword(s):  
Soil Moisture ◽  
Field Strength ◽  
Moisture Content ◽  
Soil Temperature ◽  
Output Power ◽  
Soil Moisture Content ◽  
Microwave Treatment ◽  
Soil Treatment ◽  
Internal Temperature ◽  
Soil Disinfection

Microwave treatment is a green and pollution-free soil disinfection method. The application of microwaves to disinfect soil before cultivation is highly important to increase crop yields and protect the ecological environment. The electromagnetic field is an important parameter influencing the soil temperature field in the process of microwave soil treatment, and the change in soil temperature directly affects soil disinfection. Therefore, this article carried out research on the heating pattern in North China loess due to microwave treatment. First, COMSOL software was employed to simulate the microwave soil treatment process to analyze microwave penetration into soil. Second, with the application of microwaves at the designed frequency produced with a 2.45-GHz tunable microwave generating microdevice, soil with water contents of 0%, 10%, 20%, and 30% was treated for 10~60 s (at 10-s time intervals), and experiments on the influence of the microwave output power, treatment time, and soil moisture content on the soil temperature were performed via the controlled variable method. The simulation results indicate that with increasing soil moisture content, the microwave frequency inside the soil model increases, and the electric field intensity value decreases in the model at the same depth. After microwaves traverse through the 20-cm soil model, the incident field strength is three orders of magnitude lower than the outgoing field strength. The results of the microwave soil treatment experiment reveal that: (1) Compared to microwave output power levels of 1.8 and 1.6 kW, a level of 2 kW is more suitable for microwave soil disinfection. (2) After treatment, the highest temperature occurs on the soil surface, not within the soil. (3) The location of the highest soil internal temperature after microwave treatment increasingly approaches the soil surface with increasing soil moisture content, and the microwave output power does not affect the location of the highest soil internal temperature. Combining the electromagnetic field simulation and microwave soil treatment experiment results, it was found that the higher the field strength is, the higher the temperature value, and the highest soil internal temperature after microwave treatment often occurs at the first electromagnetic wave peak.

Effect of Soil Moisture on Soil Temperature Field Near Buried Pipe

2012 ◽  
Vol 204-208 ◽  
pp. 650-653
Author(s):  
Jiang Li ◽  
Jun Ping Fu ◽  
Wu Gang Xie
Keyword(s):  
Thermal Conductivity ◽  
Temperature Field ◽  
Soil Moisture ◽  
Heat Exchanger ◽  
Moisture Content ◽  
Field Experiment ◽  
Soil Temperature ◽  
Soil Moisture Content ◽  
Thermal Conductivity Coefficient ◽  
Soil Thermal Conductivity

System effectiveness and useful life of heat pump are directly affected by whether the design of ground heat exchanger is reasonable or not. The efficiency of heat exchanger has a close relationship with soil thermal conductivity coefficient and heat diffusivity, while soil moisture content affects soil thermal conductivity coefficient and soil temperature field. In this paper, we perform numerical simulation on CFD software. Then we study the soil temperature changes through field experiment in different soil moisture content on field experiment and finally obtained the relationships of the moisture content with the single U ground soil temperature field.

scholarly journals Spatial-Temporal Simulations of Soil Moisture Content in a Large Basin of the Loess Plateau, China

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Zhiqi Wang ◽  
Xiaobo Feng ◽  
Zhihong Yao ◽  
Zhaolong Ma ◽  
Guodong Ji
Keyword(s):  
Land Use ◽  
Soil Moisture ◽  
Seasonal Variation ◽  
Moisture Content ◽  
Loess Plateau ◽  
Soil Moisture Content ◽  
Spatial And Temporal Variation ◽  
Slope Aspect ◽  
The Loess Plateau ◽  
Basin Scale

Soil moisture is a crucial factor limiting the growth and survival of plants on the Loess Plateau. Its level has a severe impact on plants’ growth and development and the type and distribution characteristics of communities. This study area is the Jihe Basin in the Loess Plateau, China. Multiple linear regression models with different environmental variables (land use, topographic and meteorological factors, etc.) were developed to simulate soil moisture’s spatial and temporal changes by integrating field experiments, indoor analysis, and GIS spatial analysis. The model performances were evaluated in the Jihe Basin, with soil moisture content measurements. The result shows that soil moisture content is positively correlated with soil bulk density, monthly rainfall, topographic wetness index, land use coefficient, and slope aspect coefficient but negatively correlated with the monthly-averaged temperature and the relative elevation coefficient. The selected variables are all related to the soil moisture content and can account for 75% of the variations of soil moisture content, and the remaining 25% of the variations are related to other factors. Comparing the simulated and measured values at all sampling points shows that the average error of all the simulated values is 0.09, indicating that the simulation has high accuracy. The spatial distribution of soil moisture content is significantly affected by land use and topographic factors, and seasonal variation is remarkable in the year. Seasonal variation of soil moisture content is determined by the seasonal variation of rainfall and the air temperature (determining evaporation) and vegetation growth cycle. Therefore, the proposed model can simulate the spatial and temporal variation of soil moisture content and support developing the soil and water loss model on a basin scale.

STUDIES ON RHIZOCTONIA SOLANI KÜHN.: IV. EFFECT OF SOIL TEMPERATURE AND MOISTURE ON VIRULENCE

1938 ◽  
Vol 16c (5) ◽  
pp. 203-213 ◽  
Author(s):  
G. B. Sanford
Keyword(s):  
Growth Rate ◽  
Soil Moisture ◽  
Moisture Content ◽  
Soil Temperature ◽  
Growth Rates ◽  
Nutrient Medium ◽  
Soil Moisture Content ◽  
Soil Temperatures ◽  
Dry Soil ◽  
Soil Temperature And Moisture

The effects of soil temperatures between 16° and 25 °C., and of soil moisture content between 19 and 40% of the moisture-holding capacity, on the virulence and type of attack of Rhizodonia Solani on young potato sprouts, were studied under controlled conditions and the results from 13 separate tests are discussed. The comparative growth rates of the pathogen on nutrient agar and in soil are outlined.At 25 °C. the disease diminished very abruptly. Between 23° and 16 °C., the pathogen appeared equally virulent throughout the range of soil moisture mentioned. The fluctuations which occurred in separate tests were not definite or consistent enough to warrant a conclusion that the virulence is greater at 16° than at 23°, or that a dry soil is more or less favorable to it than a wet one.In a fertile, steam sterilized loam, at medium moisture content, it required about ten days for the pathogen to grow as far as it did on the surface of a nutrient medium in four days. The growth rate at either 23° or 16 °C. was slightly higher in a wet soil than in one of medium moisture content, but in a dry soil the rate was somewhat less at 23° than at 16° in a medium or wet soil. Even in a fairly dry soil (19% moisture-holding capacity) at 16° the growth of the pathogen covered a distance of 5 cm. in ten days, which would appear adequate for infection of young sprouts from a set bearing viable sclerotia.The effort of the host to recover, by means of secondary and tertiary sprouts from the attacked primary sprout, was better in a wet soil than in a dry one at both 16° and 23 °C. The best effort was in a wet soil at 23°. A distinction is made between the effects of soil moisture and temperature in stimulating growth of the host, and their effect on parasitism itself.The remarkable tendency of the secondary sprouts to escape infection, regardless of soil temperature and soil moisture, is indicated. There was evidence that certain factors other than soil temperature and moisture may play an important role in the parasitism of R. Solani.

Seasonal denitrification rates under corn (Zea mays L.) in two Quebec soils

1997 ◽  
Vol 77 (1) ◽  
pp. 21-25 ◽  
Author(s):  
B. C. Liang ◽  
A. F. MacKenzie
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Zea Mays L ◽  
Denitrification Rate ◽  
Nitrous Oxide Emissions ◽  
Soil Core ◽  
Fertilizer N ◽  
Management Procedures

Nitrogen losses in soil through denitrification are important due to reduced agronomic effectiveness and environmental concerns with nitrous oxide emissions. Knowledge of denitrification may allow for management procedures to reduce these losses. Field experiments were conducted in 1991 and 1992 to investigate N fertilizer effects on denitrification under corn (Zea mays L.) on two soils of contrasting texture in southwestern Quebec. Soil core incubation with C2H2 was used to assess denitrification rates. Total calculated denitrification rate from April to November in 1991 and 1992 varied from 4 to 41 kg N ha−1 on a Chicot sandy clay loam and from 29 to 53 kg N ha−1 on a Ste. Rosalie clay. Denitrification rates increased linearly with increasing fertilizer N rates only in the Ste. Rosalie clay in 1991. Denitrification in the Ste. Rosalie soil was positively related to temperature and NO3− levels in April and May, moisture content from August to November, and temperature in October and November. Denitrification in the Chicot soil was positively related to soil moisture content and NO3− levels in April and May, and soil moisture content in June. Reducing soil NO3− concentrations in April and May could decrease denitrification rate in both Chicot and Ste. Rosalie soils. Key words: Denitrification, fertilizer N, temperature, moisture content

scholarly journals Predicting aflatoxin content in peanuts using ambient temperature, soil temperature and soil moisture content during pod development

2019 ◽  
Vol 13 (3) ◽  
pp. 59-69
Author(s):  
Muma Chalwe Hendrix ◽  
Isaac Lungu Obed ◽  
Mutiti Mweetwa Alice ◽  
Phiri Elijah ◽  
Yengwe Jones ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Ambient Temperature ◽  
Soil Temperature ◽  
Soil Moisture Content ◽  
Aflatoxin Content ◽  
Pod Development
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