scholarly journals Studies on the Microclimate in the Vegetations of Tame Pastures in Summer : I. On the effect of irrigation, pasture mixture and clipping on the soil temperature In pastures : II. On the daily variations of air temperature and relative humidity in the vegetations and on the evapo-transpiration of orchardgrass and ladino clover

1959 ◽  
Vol 28 (1) ◽  
pp. 94-97 ◽  
Author(s):  
S. KAWANABE ◽  
M. MITSUDERA ◽  
K. TAKAHASHI ◽  
N. TSUNEOKA ◽  
T. YAMADA ◽  
...  
MAUSAM ◽  
2022 ◽  
Vol 73 (1) ◽  
pp. 161-172
Author(s):  
ANANTA VASHISTH ◽  
DEBASISH ROY ◽  
AVINASH GOYAL ◽  
P. KRISHNAN

Field experiments were conducted on the research farm of IARI, New Delhi during Rabi 2016-17 and 2017-18. Three varieties of wheat (PBW-723, HD-2967 and HD-3086) were sown on three different dates for generating different weather condition during various phenological stages of crop. Results showed that during early crop growth stages soil moisture had higher value and soil temperature had lower value and with progress of crop growth stage, the moisture in the upper layer decreased and soil temperature increased significantly as compared to the bottom layers. During tillering and jointing stage, air temperature within canopy was more and relative humidity was less while during flowering and grain filling stage, air temperature within canopy was less and relative humidity was more in timely sown crop as compared to late and very late sown crop. Radiation use efficiency and relative leaf water content had significantly higher value while leaf water potential had lower value in timely sown crop followed by late and very late sown crop. Yield had higher value in HD-3086 followed by HD-2967 and PBW-723 in all weather conditions. Canopy air temperature difference had positive value in very late sown crop particularly during flowering and grain-filling stages. This reflects in the yield. Yield was more in timely sown crop as compared to late and very late sown crop.  


Plant Disease ◽  
2007 ◽  
Vol 91 (11) ◽  
pp. 1436-1444 ◽  
Author(s):  
D. L. Smith ◽  
J. E. Hollowell ◽  
T. G. Isleib ◽  
B. B. Shew

In North Carolina, losses due to Sclerotinia blight of peanut, caused by the fungus Sclerotinia minor, are an estimated 1 to 4 million dollars annually. In general, peanut (Arachis hypogaea) is very susceptible to Sclerotinia blight, but some partially resistant virginia-type cultivars are available. Up to three fungicide applications per season are necessary to maintain a healthy crop in years highly favorable for disease development. Improved prediction of epidemic initiation and identification of periods when fungicides are not required would increase fungicide efficiency and reduce production costs on resistant and susceptible cultivars. A Sclerotinia blight disease model was developed using regression strategies in an effort to describe the relationships between modeled environmental variables and disease increase. Changes in incremental disease incidence (% of newly infected plants of the total plant population per plot) for the 2002–2005 growing seasons were statistically transformed and described using 5-day moving averages of modeled site-specific weather variables (localized, mathematical estimations of weather data derived at a remote location) obtained from SkyBit (ZedX, Inc.). Variables in the regression to describe the Sclerotinia blight disease index included: mean relative humidity (linear and quadratic), mean soil temperature (quadratic), maximum air temperature (linear and quadratic), maximum relative humidity (linear and quadratic), minimum air temperature (linear and quadratic), minimum relative humidity (linear and quadratic), and minimum soil temperature (linear and quadratic). The model explained approximately 50% of the variability in Sclerotinia blight index over 4 years of field research in eight environments. The relationships between weather variables and Sclerotinia blight index were independent of host partial resistance. Linear regression models were used to describe progress of Sclerotinia blight on cultivars and breeding lines with varying levels of partial resistance. Resistance affected the rate of disease progress, but not disease onset. The results of this study will be used to develop site- and cultivar-specific spray advisories for Sclerotinia blight.


HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 778C-778
Author(s):  
Kun Xu* ◽  
Xiufeng Wang ◽  
Fang Wang

Mulching with straw increase soil water content, air relative humidity and air temperature, but decreased soil temperature. Though mulching with straw didn't change light intensity, ginger growth and yield were the same as shading. The growth and yield under shading and mulching with straw were both higher than that of naked soil.


Weed Science ◽  
1969 ◽  
Vol 17 (3) ◽  
pp. 304-306 ◽  
Author(s):  
R. H. Sedgley ◽  
L. Boersma

Rates of photosynthesis, respiration, and transpiration of wheat (Triticum aestivum L., var. Gaines) were determined as functions of time, under controlled conditions of moderate soil water stress and soil temperature, after treatment of the roots with 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron). Air temperature, relative humidity, light intensity, and air movement were maintained constant. The rate of photosynthesis declined with time for all plants treated with diuron but not for the controls. No change in the rate of respiration was detected. The rate of transpiration decreased slightly immediately upon application of the diuron and then remained constant. The data indicate that soil temperature and soil water stress play important roles in the herbicidal action of diuron applied to the soil.


Irriga ◽  
2002 ◽  
Vol 7 (3) ◽  
pp. 230-240 ◽  
Author(s):  
Marcelo Augusto De Aguiar e Silva ◽  
João Francisco Escobado ◽  
Emerson Galvani

INFLUÊNCIA DA CULTURA DO PIMENTÃO (Capsicum annuum L.) NOS ELEMENTOS AMBIENTAIS EM AMBIENTE PROTEGIDO   Marcelo Augusto de Aguiar e SilvaJoão Francisco EscobedoEmerson GalvaniSetor de Ciências Ambientais, Departamento de Recursos Naturais, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP. CP 237, CEP: 18603-970. E-mail: [email protected]   1 RESUMO              No presente trabalho foram avaliados os elementos ambientais: temperatura do solo, temperatura e umidade relativa do ar, nas condições de ambiente protegido (coberto com polietileno) e de campo, num período sem cultura (solo sem cobertura vegetal) e num outro com a cultura do pimentão, em anos diferentes, nas condições climáticas de Botucatu, SP. O híbrido de pimentão utilizado foi o Margarita, que apresenta frutos vermelhos quando maduros. A temperatura do solo foi monitorada por dois sensores eletrônicos instalados a 0,1m de profundidade, sendo um na condição de ambiente protegido e outro na condição de campo, e a temperatura e umidade do ar foram monitoradas por dois sensores eletrônicos instalados a 2m de altura (ambiente protegido e campo). O efeito do pimentão alterando o microclima de cultivo foi observado na temperatura do solo, que apresentou menores valores do índice no período com a cultura, uma vez que o dossel funcionou como uma barreira física que impediu que a radiação solar chegasse ao solo. Os valores encontrados para o índice da temperatura e umidade relativa do ar no período sem a cultura foram muito próximos aos encontrados no período com a cultura, não caracterizando o efeito do pimentão sobre essas variáveis.  UNITERMOS: Influência da cultura, temperatura do solo, temperatura e umidade do ar, pimentão.   AGUIAR E SILVA, M. A.; ESCOBEDO, J. F.; GALVANI, E.  INFLUENCE OF BELL PEPPER CROP (Capsicum annuum L.) ON GREENHOUSE ENVIRONMENTAL VARIABLES   2 ABSTRACT              The objective of this research was to evaluate the effect of bell pepper on climatic variables such as air temperature and relative humidity as well as soil temperature. The measurements were obtained under greenhouse and field environmental conditions taking into account two soil cover situations: without vegetation and with bell pepper crop (Margarida hybrid). The research was carried out in an experimental area of the Environmental Sciences Section of the Natural Resource Department, FCA/UNESP, Campus of Botucatu-SP, from June 1st to September 5th 1999 (without crop) and June 1st to September 5th 2000 (with crop). Soil temperature was monitored by two electronic sensors installed at 0,1 meter depth, inside and outside the greenhouse. Air temperature and relative humidity were monitored by two electronic sensors installed at 2m height, inside and outside the greenhouse. The effect of bell pepper on crop microclimate was evidenced by soil temperature which showed index mean values 1.04 (without crop) and 0.95 (with crop). Crop canopy acted as a physical barrier blocking solar radiation. Air temperature and relative humidity mean indexes did not present significant differences between periods with and without crop.  KEYWORDS: Soil temperature, air temperature, air relative humidity, bell pepper.


2012 ◽  
Vol 13 (2) ◽  
pp. 573-587 ◽  
Author(s):  
Xiaohang Wen ◽  
Shihua Lu ◽  
Jiming Jin

Abstract Land use/cover types derived by satellite remote sensing data from the Earth Observing System Moderate Resolution Imaging Spectroradiometer (MODIS) were used to replace the U.S. Geological Survey (USGS) data in the Weather Research and Forecasting Model (WRF). Simulations in this study were further improved by modifying the initial fields of WRF with soil temperature and moisture observations, because these two variables are important to producing “cold–wet island” effects. A series of WRF simulations were performed to describe microclimate characteristics and the local thermal circulation generated by the inhomogeneous surface over the Jinta oasis, which is located in Gansu—a northwestern province of China. Comparison between simulations and observations showed that the WRF results produced with observed soil temperature and moisture initializations agreed well with near-surface measurements of air temperature, relative humidity, and wind direction. Moreover, low temperatures over the oasis were found to coexist with high temperatures over the bare land, further leading to developments of local atmospheric circulation. The simulated winds over the oasis showed airmass divergence over the surface layer, triggering local circulation in the upper level. The integration of the MODIS land use/cover data with WRF and the initialization of WRF’s soil temperature and moisture with in situ observations improved the simulations in air temperature, relative humidity, and heat fluxes. These improvements enabled the WRF to reproduce the observed “cold and wet island” effects of the oasis.


Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 771
Author(s):  
Li-Wei Liu ◽  
Sheng-Hsin Hsieh ◽  
Su-Ju Lin ◽  
Yu-Min Wang ◽  
Wen-Shin Lin

This study aimed to establish a machine learning (ML)-based rice blast predicting model to decrease the appreciable losses based on short-term environment data. The average, highest and lowest air temperature, average relative humidity, soil temperature and solar energy were selected for model development. The developed multilayer perceptron (MLP), support vector machine (SVM), Elman recurrent neural network (Elman RNN) and probabilistic neural network (PNN) were evaluated by F-measures. Finally, a sensitivity analysis (SA) was conducted for the factor importance assessment. The study result shows that the PNN performed best with the F-measure (β = 2) of 96.8%. The SA was conducted in the PNN model resulting in the main effect period is 10 days before the rice blast happened. The key factors found are minimum air temperature, followed by solar energy and equaled sensitivity of average relative humidity, maximum air temperature and soil temperature. The temperature phase lag in air and soil may cause a lower dew point and suitable for rice blast pathogens growth. Through this study’s results, rice blast warnings can be issued 10 days in advance, increasing the response time for farmers preparing related preventive measures, further reducing the losses caused by rice blast.


2017 ◽  
Vol 12 (1) ◽  
pp. 97-106 ◽  
Author(s):  
Purnima Mehta ◽  
P. K Baweja ◽  
R. K. Aggarwal

A study was carried out on “Impact of micro-climatic variations on forest ecosystem in mid hills of Himachal Pradesh” during winter and summer seasons of 2015-16. Comparisons of below forest canopy and open sites were carried out for abiotic and biotic factors under five forest ecosystems (chir pine forest, mixed forest, ban oak forest, agriculture field and bare area) and analysed the forest influence on local winter and summer climate according to forest type, soil type, slope orientation, tree height and diameter at breast height by using RBD design. Seasonal and diurnal variations in microclimatic variables viz., air temperature, soil temperature, relative humidity, wind speed and wind direction were measured with Portable weather station (Delta T) at afternoon 2:00-4:00 PM fortnightly in each forest ecosystem and bare area during winter and summer season. Solar radiation and albedo were measured with Pyranometer (Kipp and Zonen) at 1.35 m height. A significant decrease was attained in below forest canopy and bare area data for ambient temperature (2.5-5.0 oC), soil temperature (1.5-3.6 oC) solar radiation (13.2-47.4 Wm-2), albedo (0.15-0.21) and increased relative humidity (7-18%), soil moisture (8.0-15.2%). Among different forest ecosystem, the diurnal trends in microclimatic parameters showed large variations. The ambient air temperature ranged from 02.2-16.3 oC and 14.2- 30.7 oC where as soil temperature ranged from 07.4- 16.5 oC and 15.4-32.7 oC, however relative humidity ranged from 37- 88 per cent and 14-60 per cent among different forest ecosystem during winter and summer seasons, respectively. Mico-climatic variables under Ban-Oak forest revealed significant lowest air temperature, highest relative humidity and less wind speed.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrea de Almeida Brito ◽  
Heráclio Alves de Araújo ◽  
Gilney Figueira Zebende

AbstractDue to the importance of generating energy sustainably, with the Sun being a large solar power plant for the Earth, we study the cross-correlations between the main meteorological variables (global solar radiation, air temperature, and relative air humidity) from a global cross-correlation perspective to efficiently capture solar energy. This is done initially between pairs of these variables, with the Detrended Cross-Correlation Coefficient, ρDCCA, and subsequently with the recently developed Multiple Detrended Cross-Correlation Coefficient, $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2. We use the hourly data from three meteorological stations of the Brazilian Institute of Meteorology located in the state of Bahia (Brazil). Initially, with the original data, we set up a color map for each variable to show the time dynamics. After, ρDCCA was calculated, thus obtaining a positive value between the global solar radiation and air temperature, and a negative value between the global solar radiation and air relative humidity, for all time scales. Finally, for the first time, was applied $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}$$DMCx2 to analyze cross-correlations between three meteorological variables at the same time. On taking the global radiation as the dependent variable, and assuming that $${\boldsymbol{DM}}{{\boldsymbol{C}}}_{{\bf{x}}}^{{\bf{2}}}={\bf{1}}$$DMCx2=1 (which varies from 0 to 1) is the ideal value for the capture of solar energy, our analysis finds some patterns (differences) involving these meteorological stations with a high intensity of annual solar radiation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Kevin Lanza ◽  
Melody Alcazar ◽  
Deanna M. Hoelscher ◽  
Harold W. Kohl

Abstract Background Latinx children in the United States are at high risk for nature-deficit disorder, heat-related illness, and physical inactivity. We developed the Green Schoolyards Project to investigate how green features—trees, gardens, and nature trails—in school parks impact heat index (i.e., air temperature and relative humidity) within parks, and physical activity levels and socioemotional well-being of these children. Herein, we present novel methods for a) observing children’s interaction with green features and b) measuring heat index and children’s behaviors in a natural setting, and a selection of baseline results. Methods During two September weeks (high temperature) and one November week (moderate temperature) in 2019, we examined three joint-use elementary school parks in Central Texas, United States, serving predominantly low-income Latinx families. To develop thermal profiles for each park, we installed 10 air temperature/relative humidity sensors per park, selecting sites based on land cover, land use, and even spatial coverage. We measured green features within a geographic information system. In a cross-sectional study, we used an adapted version of System for Observing Play and Recreation in Communities (SOPARC) to assess children’s physical activity levels and interactions with green features. In a cohort study, we equipped 30 3rd and 30 4th grade students per school during recess with accelerometers and Global Positioning System devices, and surveyed these students regarding their connection to nature. Baseline analyses included inverse distance weighting for thermal profiles and summing observed counts of children interacting with trees. Results In September 2019, average daily heat index ranged 2.0 °F among park sites, and maximum daily heat index ranged from 103.4 °F (air temperature = 33.8 °C; relative humidity = 55.2%) under tree canopy to 114.1 °F (air temperature = 37.9 °C; relative humidity = 45.2%) on an unshaded playground. 10.8% more girls and 25.4% more boys interacted with trees in September than in November. Conclusions We found extreme heat conditions at select sites within parks, and children positioning themselves under trees during periods of high heat index. These methods can be used by public health researchers and practitioners to inform the redesign of greenspaces in the face of climate change and health inequities.


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