scholarly journals Study of microclimatic conditions under different environments in wheat crop

MAUSAM ◽  
2021 ◽  
Vol 47 (1) ◽  
pp. 81-84
Author(s):  
O. P. BISHNOI ◽  
RAM NIWAS ◽  
SURINDER SINGH ◽  
MOHAN SINGH
Keyword(s):  
Soil Moisture ◽  
Wind Speed ◽  
Leaf Temperature ◽  
Wheat Crop ◽  
Leaf Wetness ◽  
Sowing Time ◽  
Air Temperatures ◽  
Yield Production ◽  
Microclimatic Conditions ◽  
Microclimate Conditions

An experiment was cunducted to study the wheal microclimate for higher grain yield production at research farm of Hisar 'Agriculture’ University (HAU). Profiles of temperature relative humidity, leaf temperature leaf wetness wind speed were measured in the crop canopies of different sowing treatments. Higher air temperatures and lower soil moisture were observed during reproductive phase under delayed sowings. Albedo varied between 0.19 and 0.23. Test weight decreased with delay in sowing time. Sowing of wheat between 31 October and 14 November produced statistically higher yield under favourable microclimate conditions at dirrerent phenophases.

scholarly journals The Response of Muskmelon Growth and Development to Microclimate Modification by Shelterbelts

HortScience ◽  
1999 ◽  
Vol 34 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Dongsheng Zhang ◽  
James R. Brandle ◽  
Kenneth G. Hubbard ◽  
Laurie Hodges ◽  
Entin Daningsih
Keyword(s):  
Soil Moisture ◽  
Wind Speed ◽  
Relative Humidity ◽  
Growth And Development ◽  
Agricultural Research ◽  
Growth Parameters ◽  
Female Flower ◽  
Growing Season ◽  
Dry Matter Accumulation ◽  
Air Temperatures

The relationships between shelterbelt (tree windbreak)-induced microclimate and muskmelon (Cucumis melo L.) growth and development were investigated at the Univ. of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Nebr., during the 1992 and 1993 growing seasons. Wind speed, wind direction, air and soil temperatures, relative humidity, and soil moisture were monitored in both sheltered and nonsheltered areas. Plant growth parameters (plant height, vine length, plant dry weight, and leaf area) were measured at various stages of development. Shelterbelts provided improved growing conditions for muskmelon transplants. Direct wind damage and duration of higher wind speeds were reduced 47% to 56% in sheltered areas. Air temperatures in sheltered areas were slightly higher during daytime and slightly lower at night, and significantly so early in the growing season. Relative humidity was increased significantly in sheltered areas in 1992 and, while higher in 1993, the difference was nonsignificant. Soil moisture content was not affected significantly by wind protection. Sheltered plants exhibited earlier development and faster growth. The first female flower appeared 2 days earlier in sheltered areas in both years. The first fruit set, as indicated by fruit swelling and retention on the vine, occurred 6 days earlier and matured 5 and 6 days earlier in sheltered areas in 1992 and 1993, respectively. Leaf areas and dry-matter accumulation of sheltered plants were greater than those of exposed plants. The shoot relative growth rate of sheltered plants increased earlier in the growing season, but decreased slightly later in the growing season. The earlier development and faster growth of sheltered plants were related mainly to the reduction of wind speed, higher total accumulated air temperatures during the daylight hours (sum of daily average daytime air temperatures based on hourly averages), and higher soil temperature in sheltered areas. Total yields were not affected significantly in either year; however, early yields were significantly greater in sheltered areas in 1993. If earlier maturity and increased yield are possible in large sheltered fields, this practice would provide an economic benefit to producers.

Characterizing the convective heat exchange with plastic shading nets under natural arid conditions

2019 ◽  
pp. 11-20
Author(s):  
Ahmed M Abdel-Ghanya ◽  
Ibrahim M Al-Helal
Keyword(s):  
Wind Speed ◽  
Thermal Radiation ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Convective Heat Exchange ◽  
Radiative Properties ◽  
Wooden Frame ◽  
Arid Conditions ◽  
Air Temperatures ◽  
Radiation Fluxes

Plastic nets are extensively used for shading purposes in arid regions such as in the Arabian Peninsula. Quantifying the convection exchange with shading net and understanding the mechanisms (free, mixed and forced) of convection are essential for analyzing energy exchange with shading nets. Unlike solar and thermal radiation, the convective energy, convective heat transfer coefficient and the nature of convection have never been theoretically estimated or experimentally measured for plastic nets under arid conditions. In this study, the convected heat exchanges with different plastic nets were quantified based on an energy balance applied to the nets under outdoor natural conditions. Therefore, each net was tacked onto a wooden frame, fixed horizontally at 1.5-m height over the floor. The downward and upward solar and thermal radiation fluxes were measured below and above each net on sunny days; also the wind speed over the net, and the net and air temperatures were measured, simultaneously. Nets with different porosities, colors and texture structures were used for the study. The short and long wave’s radiative properties of the nets were pre-determined in previous studies to be used. Re and Gr numbers were determined and used to characterize the convection mechanism over each net. The results showed that forced and mixed convection are the dominant modes existing over the nets during most of the day and night times. The nature of convection over nets depends mainly on the wind speed, net-air temperature difference and texture shape of the net rather than its color and its porosity.

Silvicultural treatments, microclimatic conditions and seedling response in Southern Interior clearcuts

1998 ◽  
Vol 78 (1) ◽  
pp. 115-126 ◽  
Author(s):  
R. L. Fleming ◽  
T. A. Black ◽  
R. S. Adams ◽  
R. J. Stathers
Keyword(s):  
Soil Moisture ◽  
Seedling Establishment ◽  
Initial Period ◽  
Mineral Soil ◽  
Soil Disturbance ◽  
Near Surface ◽  
Lower Elevation ◽  
Organic Horizons ◽  
Soil Temperatures ◽  
Microclimatic Conditions

Post-harvest levels of soil disturbance and vegetation regrowth strongly influence microclimate conditions, and this has important implications for seedling establishment. We examined the effects of blading (scalping), soil loosening (ripping) and vegetation control (herbicide), as well as no soil disturbance, on growing season microclimates and 3-yr seedling response on two grass-dominated clearcuts at different elevations in the Southern Interior of British Columbia. Warmer soil temperatures were obtained by removing surface organic horizons. Ripping produced somewhat higher soil temperatures than scalping at the drier, lower-elevation site, but slightly reduced soil temperatures at the wetter, higher-elevation site. Near-surface air temperatures were more extreme (higher daily maximums and lower daily minimums) over the control than over exposed mineral soil. Root zone soil moisture deficits largely reflected transpiration by competing vegetation; vegetation removal was effective in improving soil moisture availability at the lower elevation site, but unnecessary from this perspective at the higher elevation site. The exposed mineral surfaces self-mulched and conserved soil moisture after an initial period of high evaporation. Ripping and scalping resulted in somewhat lower near-surface available soil water storage capacities. Seedling establishment on both clearcuts was better following treatments which removed vegetation and surface organic horizons and thus enhanced microclimatic conditions, despite reducing nutrient supply. Such treatments may, however, compromise subsequent stand development through negative impacts on site nutrition. Temporal changes in the relative importance of different physical (microclimate) and chemical (soil nutrition) properties to soil processes and plant growth need to be considered when evaluating site productivity. Key words: Microclimate, soil temperature, air temperature, soil moisture, clearcut, seedling establishment

A MOISTURE STRESS INDEX FOR WHEAT BY MEANS OF A MODULATED SOIL MOISTURE BUDGET

1968 ◽  
Vol 48 (5) ◽  
pp. 535-544 ◽  
Author(s):  
A. R. Mack ◽  
W. S. Ferguson
Keyword(s):  
Soil Moisture ◽  
Stress Function ◽  
Potential Evapotranspiration ◽  
Moisture Stress ◽  
Moisture Distribution ◽  
Stress Index ◽  
Wheat Crop ◽  
Moisture Budget ◽  
Dough Stage ◽  
Soil Moisture Budget

Actual evapotranspiration (AE), soil moisture distribution, and moisture stress for a wheat crop (PE-AE) were estimated by the modulated soil moisture budget of Holmes and Robertson. The estimated soil moisture was reasonably well correlated with soil moisture measured weekly by means of gypsum blocks. Wheat yields from experimental plots in the corresponding area were related more closely to the moisture stress function (PE-AE: r = − 0.83), than to the seasonal precipitation (r = 0.62), the potential evapotranspiration (PE) or the evapotranspiration ratio (AE/PE). Regression analyses showed that the grain yields were reduced by an average of 156 (±sb = 40) kg/ha per cm of moisture stress from emergence to harvest, or by 311 and 69 kg/ha per cm of stress, from the fifth-leaf to the soft-dough stage and from the soft-dough stage to maturity, respectively. The moisture stress function may be used to characterize the soil–plant–atmosphere environment for the growing season of a crop. Precipitation and evapotranspiration data are presented annually for three standardized growing periods at Brandon from 1921 to 1963.

Effects of Different Nitrogen Fertilizers and Humic Acid On Wheat Crop Irrigated With Different Water Regime Using 15N

2021 ◽  
Vol 50 (2) ◽  
pp. 261-267
Author(s):  
Ahmed A Moursy ◽  
MM Ismail
Keyword(s):  
Dry Matter ◽  
Water Regime ◽  
Soil Depth ◽  
N Uptake ◽  
Nitrogen Fertilizers ◽  
Wheat Crop ◽  
Water Requirements ◽  
Applied Water ◽  
Yield Production ◽  
Uptake Data

A field experiment was conducted to observe effects of water requirements and different fertilizers on wheat crop’s yield, production and N uptake. Data showed that dry matter yield of wheat grain was higher with Hu + AS (5.82 mt/ha) compared with applied water 100% ETC. Concerning the rate of water regime, the best significant grain yield of wheat was obtained with 100% ETc (4.23 mt/ha). Nitrogen derived from fertilizer Ndff% with 50% ETC of water was 28.41 and 27.28% for grain and straw, respectively. At 100% ETC of water the Ndff% was 30.16 and 27.75% for grain and straw, respectively. Nitrogen utilized by grains and straw was more efficient under treatment Hu + AS combined with 50% Etc, 100% Etc recording 15.6 and 32.23%, respectively. At 50% ETC of water requirements for wheat crop, higher N remained in 0 - 15, 15 - 30 and 30 - 45 cm soil depth were nearly closed to each other compared with the treatment made at 100% ETC of water requirements. Bangladesh J. Bot. 50(2): 261-267, 2021 (June)

scholarly journals Pan-Arctic linkages between snow accumulation and growing-season air temperature, soil moisture and vegetation

2013 ◽  
Vol 10 (11) ◽  
pp. 7575-7597 ◽  
Author(s):  
K. A. Luus ◽  
Y. Gel ◽  
J. C. Lin ◽  
R. E. J. Kelly ◽  
C. R. Duguay
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Land Surface ◽  
Regional Scale ◽  
Surface Characteristics ◽  
Growing Season ◽  
Snow Accumulation ◽  
Snow Season ◽  
Air Temperatures ◽  
Land Surface Characteristics

Abstract. Arctic field studies have indicated that the air temperature, soil moisture and vegetation at a site influence the quantity of snow accumulated, and that snow accumulation can alter growing-season soil moisture and vegetation. Climate change is predicted to bring about warmer air temperatures, greater snow accumulation and northward movements of the shrub and tree lines. Understanding the responses of northern environments to changes in snow and growing-season land surface characteristics requires: (1) insights into the present-day linkages between snow and growing-season land surface characteristics; and (2) the ability to continue to monitor these associations over time across the vast pan-Arctic. The objective of this study was therefore to examine the pan-Arctic (north of 60° N) linkages between two temporally distinct data products created from AMSR-E satellite passive microwave observations: GlobSnow snow water equivalent (SWE), and NTSG growing-season AMSR-E Land Parameters (air temperature, soil moisture and vegetation transmissivity). Due to the complex and interconnected nature of processes determining snow and growing-season land surface characteristics, these associations were analyzed using the modern nonparametric technique of alternating conditional expectations (ACE), as this approach does not impose a predefined analytic form. Findings indicate that regions with lower vegetation transmissivity (more biomass) at the start and end of the growing season tend to accumulate less snow at the start and end of the snow season, possibly due to interception and sublimation. Warmer air temperatures at the start and end of the growing season were associated with diminished snow accumulation at the start and end of the snow season. High latitude sites with warmer mean annual growing-season temperatures tended to accumulate more snow, probably due to the greater availability of water vapor for snow season precipitation at warmer locations. Regions with drier soils preceding snow onset tended to accumulate greater quantities of snow, likely because drier soils freeze faster and more thoroughly than wetter soils. Understanding and continuing to monitor these linkages at the regional scale using the ACE approach can allow insights to be gained into the complex response of Arctic ecosystems to climate-driven shifts in air temperature, vegetation, soil moisture and snow accumulation.

scholarly journals Green roofs and cool materials as retrofitting strategies for urban heat island mitigation: Case study in Belgrade, Serbia

2018 ◽  
Vol 22 (6 Part A) ◽  
pp. 2309-2324
Author(s):  
Marija Lalosevic ◽  
Mirko Komatina ◽  
Marko Milos ◽  
Nedzad Rudonja
Keyword(s):  
Green Roofs ◽  
Urban Heat Islands ◽  
Temperature Changes ◽  
Heat Islands ◽  
Air Temperatures ◽  
Urban Heat ◽  
Microclimatic Conditions ◽  
Typical Summer ◽  
Planning And Construction ◽  
The Impact

The effect of extensive and intensive green roofs on improving outdoor microclimate parameters of urban built environments is currently a worldwide focus of research. Due to the lack of reliable data for Belgrade, the impact of extensive and intensive green roof systems on mitigating the effects of urban heat islands and improving microclimatic conditions by utilizing high albedo materials in public spaces were studied. Research was conducted on four chosen urban units within existing residential blocks in the city that were representative of typical urban planning and construction within the Belgrade metropolitan area. Five different models (baseline model and four potential models of retrofitting) were designed, for which the temperature changes at pedestrian and roof levels at 07:00, 13:00, 19:00 h, on a typical summer day, and at 01:00 h, the following night in Belgrade were investigated. The ENVI-met software was used to model the simulations. The results of numerical modeling showed that utilizing green roofs in the Belgrade climatic area could reduce air temperatures in the surroundings up to 0.47, 1.51, 1.60, 1.80 ?C at pedestrian level and up to 0.53, 1.45, 0.90, 1.45 ?C at roof level for four potential retrofitting strategies, respectively.

scholarly journals Assimilation of Satellite-Derived Soil Moisture for Improved Forecasts of the Great Plains Low-Level Jet

2020 ◽  
Vol 148 (11) ◽  
pp. 4607-4627
Author(s):  
Craig R. Ferguson ◽  
Shubhi Agrawal ◽  
Mark C. Beauharnois ◽  
Geng Xia ◽  
D. Alex Burrows ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Wind Speed ◽  
Data Assimilation ◽  
Great Plains ◽  
Wrf Model ◽  
Added Value ◽  
Low Level ◽  
Convective Systems ◽  
South Central ◽  
Mesoscale Convective

AbstractIn the context of forecasting societally impactful Great Plains low-level jets (GPLLJs), the potential added value of satellite soil moisture (SM) data assimilation (DA) is high. GPLLJs are both sensitive to regional soil moisture gradients and frequent drivers of severe weather, including mesoscale convective systems. An untested hypothesis is that SM DA is more effective in forecasts of weakly synoptically forced, or uncoupled GPLLJs, than in forecasts of cyclone-induced coupled GPLLJs. Using the NASA Unified Weather Research and Forecasting (NU-WRF) Model, 75 GPLLJs are simulated at 9-km resolution both with and without NASA Soil Moisture Active Passive SM DA. Differences in modeled SM, surface sensible (SH) and latent heat (LH) fluxes, 2-m temperature (T2), 2-m humidity (Q2), PBL height (PBLH), and 850-hPa wind speed (W850) are quantified for individual jets and jet-type event subsets over the south-central Great Plains, as well as separately for each GPLLJ sector (entrance, core, and exit). At the GPLLJ core, DA-related changes of up to 5.4 kg m−2 in SM can result in T2, Q2, LH, SH, PBLH, and W850 differences of 0.68°C, 0.71 g kg−2, 59.9 W m−2, 52.4 W m−2, 240 m, and 4 m s−1, respectively. W850 differences focus along the jet axis and tend to increase from south to north. Jet-type differences are most evident at the GPLLJ exit where DA increases and decreases W850 in uncoupled and coupled GPLLJs, respectively. Data assimilation marginally reduces negative wind speed bias for all jets, but the correction is greater for uncoupled GPLLJs, as hypothesized.

scholarly journals The Influence of Some Phytotechnical Elements on Attaque of Diabrotica Virgifera Virgifera Le Conte (The Western Root Worm) in Maize from Crisurilor Plain

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Cornelia CIOBANU ◽  
Cornel DOMUŢA ◽  
Gheorghe CIOBANU ◽  
Maria ŞANDOR ◽  
Alina Dora SAMUEL ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Diabrotica Virgifera Virgifera ◽  
Crop Rotations ◽  
Wheat Crop ◽  
Diabrotica Virgifera ◽  
Term Trial ◽  
Lower Plant

The paper based on the researches carried out during 2005 – 2008 in the long term trial placed in 1990 on the preluvosoil from Oradea. The monoculture of maize, maize – wheat and maize – soybean – wheat crop rotations were studied in unirrigated and irrigated conditions. The crop rotatin of six years (oat + clover – clover – maize – wheat – maize - sunflower) was studied in unirrigated conditions. The researches emphasized that the monoculture is the most responsible for the pest multiplication. In maize monoculture the larvae number on the roots was ranged between 4.91-8.23 and root attack degree in IOWA scale (with marks from 1 to 6 in which maximum attack is 6), had values between 3.84 and 5.62 and the frequent of attacked plants with the symptom “goose neck” ranged between 16,4% and 31.2% and larval aggressiveness being higher in the case of favorable soil moisture in irrigated condition. The maize rotation with other plants interrupts the biologic pest cycle. The results obtained emphasize that later maize sowing alongside by the utilizing of lower plant thickness level contribute to prevention of pest multiplication, while earlier sowing at high thickness favor the larvae developing.

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