Effets de la scarification du site sur le micro-environnement

1980 ◽  
Vol 10 (4) ◽  
pp. 476-482 ◽  
Author(s):  
André P. Plamondon ◽  
Denis C. Ouellet ◽  
Gaston Déry
Keyword(s):  
Soil Water ◽  
Air Temperature ◽  
Soil Surface ◽  
The Other ◽  
Maximum Temperature ◽  
Soil Water Tension ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Water Tension ◽  
Minimum Air Temperature

Soil and air temperatures, and soil water tension were measured at two sites from June 1972 to August 1973 in order to determine the effect of scarification. This study is part of a project concerning yellow birch regeneration. The minimum air temperature at 30 cm height and at the soil surface were, respectively, 0.5 and 1.0 °C higher at the scarified site; on the other hand, the maximum temperature at 30 cm was lower. The soil temperatures during the summer were 2 to 4 °C higher at the scarified site according to the level considered. Soil water tension was much lower in the scarified station between 0 and 15 cm depth, but the effect decreased during the second summer of the study.

Soil temperatures in Egypt

1928 ◽  
Vol 18 (1) ◽  
pp. 90-122 ◽  
Author(s):  
E. McKenzie Taylor
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Soil Surface ◽  
Temperature Wave ◽  
Maximum Temperature ◽  
Straight Line ◽  
Temperature Waves ◽  
Soil Temperatures ◽  
The Times ◽  
Maximum Air Temperature

1. The soil temperatures in Egypt at a number of depths have been recorded by means of continuous recording thermometers. In general, the records show that the amplitude of the temperature wave at the surface of the soil is considerably greater than the air temperature wave. There is, however, a considerable damping of the wave with depth, no daily variation in temperature being observed at a depth of 100 cm.2. No definite relation between the air and soil temperatures could be traced. The maximum air temperature was recorded in May and the maximum soil temperature in July.3. The amplitude of the temperature wave decreases with increase in depth. The decrease in amplitude of the soil temperature wave is not regular owing to variations in the physical properties of the soil layers. Between any two depths, the ratio of the amplitudes of the temperature waves is constant throughout the year. The amplitude of the soil temperature wave bears no relation to the amplitude of the air temperature wave.4. The time of maximum temperature at the soil surface is constant throughout the year at 1 p.m. The times of maximum temperature at depths below the surface lag behind the time of surface maximum, but they are constant throughout the year. When plotted against depth, the times of maximum at the various soil depths lie on a straight line.

Efficiency of Grasshopper Baits in Relation to Time of Day of Application

1952 ◽  
Vol 84 (5) ◽  
pp. 147-155 ◽  
Author(s):  
R. H. Handford ◽  
L. G. Putnam
Keyword(s):  
Experimental Data ◽  
Surface Temperature ◽  
Air Temperature ◽  
Soil Surface ◽  
Time Of Day ◽  
Rapid Decrease ◽  
The Other ◽  
Feeding Period ◽  
Air Temperatures ◽  
Soil Surface Temperature

Literature on grasshopper control published hetween 1930 and 1942 stressed the desirability of applying poisoned bait when grasshoppers begin their first main feeding period of the day. Such pubiications include those by Parker (1930). Parker, Walton, and Shotwell (1932), Criddle (1932). Ruggles and Aamodt (1938), and Bird (1940). Parker (1930) found that the lesser migratory grasshopper, Melanoplus mexicanus mexicanus (Sauss.), fed sparingly on baits at air temperatures between 55°F. and 63°F., more actively between 64°F. and 67°F., and most actively between 68°F. and 78°F. A rapid decrease in feeding occurred when air temperature rose above 80°F. or the soil surface temperature above 113°F. Much the same relationship held also for the clear-winged grasshopper, Cammula pellucida (Scudd.). On the basis of such observations it was decided chat an air temperature of 68°F. might be classed as optimum for beginning the application of bait. Parker did not, however, indicate the degree of mortality resulting from such feeding; the other writers gave no experimental data.

scholarly journals ADAPTAÇÃO E AVALIAÇÃO DE EVAPOTRANSPIRÔMETROS PARA A OBTENÇÃO DO COEFICIENTE DE CULTURA BASAL (KCB) DO FEIJOEIRO (Phaseolus vulgaris L)

Irriga ◽  
1999 ◽  
Vol 4 (2) ◽  
pp. 61-69 ◽  
Author(s):  
Gerson Araujo de Medeiros ◽  
Flavio Bussneyer Arruda
Keyword(s):  
Phaseolus Vulgaris ◽  
Soil Water ◽  
Crop Coefficient ◽  
Soil Surface ◽  
High Water ◽  
Soil Evaporation ◽  
Phaseolus Vulgaris L ◽  
Soil Water Tension ◽  
Water Tension ◽  
E Mail

ADAPTAÇÃO E AVALIAÇÃO DE EVAPOTRANSPIRÔMETROS PARA A OBTENÇÃO DO COEFICIENTE DE CULTURA BASAL (kcb) DO FEIJOEIRO (Phaseolus vulgaris L)   Gerson Araujo de MedeirosDepartamento de Água e Solo, Faculdade de Engenharia Agrícola, UNICAMP, C. P. 6011, CEP 13.081-490, Campinas-SP. E-mail: [email protected] Bussmeyer ArrudaSeção de Irrigação e Drenagem, Instituto Agronômico, C. P. 28, CEP 13.001-970, Campinas - São Paulo. E-mail: [email protected]   1 RESUMO   O estudo do coeficiente de cultura (kc) tem ganho grande impulso ao seu entendimento e estimativa, quando feito o seu desmembramento em coeficiente de cultura basal (kcb), dependente do desenvolvimento da planta, em um coeficiente solo-planta (ka), dependente do déficit de água no solo, e um coeficiente relacionado ao molhamento da superfície do solo (ks). Uma avaliação das condições de solo e planta foi realizada em quatro evapotranspirômetros de nível freático constante e em um experimento de campo com feijoeiro semanalmente irrigado sob duas densidades de plantio. O trabalho foi conduzido no Instituto Agronômico, Campinas, no período de agosto a novembro de 1994, em um solo argiloso. A fim de se evitar a evaporação direta do solo foi aplicada sobre a superfície de cada evapotranspirômetro uma camada de 1 cm de areia sob uma outra de 1 cm do solo original da área. Observações visuais, crescimento de planta e monitoramento da tensão de água no solo nas profundidades de 5 e 10 cm  nos evapotranspirômetros, mostraram que a tensão nunca excedeu a 10 kPa em ambas as profundidades. A resistência estomática, nos evapotranspirômetros, variou de 0,4 a 1,0 s.cm-1, durante a maior parte do ciclo, excetuando-se a fase de senescência, nas condições de cultura irrigada essa variação foi de 0,5 a 2,7 s.cm-1. Desta forma, as condições exigidas para a obtenção do coeficiente de cultura basal, como recomendadas por Wright (1981), foram satisfeitas, e nas condições de campo estas não se mantiveram, mesmo em feijoeiro irrigado.   UNITERMOS: Coeficiente de cultura, evapotranspirômetro, evapotranspiração, feijoeiro.   MEDEIROS, G. A., ARRUDA, F. B. Adaptation and evaluation of evapotranspirometer to determine the basal crop coefficient (kcb) of beans (Phaseolus vulgaris l).   2 ABSTRACT   Crop coefficient (kc) studies have gained a better understanding when it was decomposed in basal crop coefficient (kcb), dependent on crop development, in a soil-plant coefficient (ka), dependent on soil water deficit, and in a coefficient related to soil surface wetting (ks). An evaluation of soil and plant conditions was performed in a four constant water table type of evapotranspirometer and in a field experiment with two planting population densities of beans weekly irrigated (60 kPa at 15 cm). The work was conducted in the Institute Agronomic, Campinas, SP, from August to November of 1994, in a clayed tropical soil. In order to avoid direct soil evaporation it was applied an 1 cm layer of sand below an other 1 cm of original soil on surface of each evapotranspirometer. Visual observations, plant growth and monitoring soil water tension at 5 cm and 10 cm in the evapotranspirometers showed that tension never exceeded 10 kPa at both positions. Leaf stomata resistance of evapotranspirometer plants ranged from 0.4 to 1.0 s.cm-1 most of the crop life compared to 0.5 to 2.7 s.cm-1 of field irrigated plants. It was concluded that the evapotranspirometers were able to maintain a high water supply to a crop with reduced direct soil evaporation, as recommended by Wright (1981), to determine basal crop coefficient, a situation rather difficult to ascertain in the field even for irrigated beans.   KEYWORDS: Crop coefficient, evapotranspirometer, evapotranspiration, bean.

scholarly journals Irrigation controller mechanically actuated by soil-water tension: II - Field evaluations

2017 ◽  
Vol 21 (5) ◽  
pp. 298-303
Author(s):  
Alexsandro C. S. Almeida ◽  
Tarlei A. Botrel ◽  
Steven R. Raine ◽  
Antonio P. de Camargo ◽  
Marinaldo F. Pinto ◽  
...  
Keyword(s):  
Soil Water ◽  
High Frequency ◽  
Root Zone ◽  
Irrigation System ◽  
Soil Surface ◽  
Field Evaluation ◽  
Water Source ◽  
Soil Water Tension ◽  
Water Tension ◽  
Hydraulic Valve

ABSTRACT In this study, a field evaluation of the performance of an irrigation controller mechanically actuated by soil-water tension (SWT) was performed. The controller employs a tensiometer used as a sensor of SWT to directly control a mechanically actuated hydraulic valve. Six controllers were installed in an orchard to control the irrigation for six rows of plants over 64 days. Each controller controlled the irrigation of one lateral drip line. The drip irrigation system was gravity-fed from a water source placed 7 m above the soil surface. The SWT and the pressure in each lateral line were measured to evaluate the performance of the controllers. All the controllers tested in the field autonomously initiated and terminated the irrigation during the evaluation. Irrigation events were initiated when values close to the set soil-tension values were reached and were terminated at lower soil-tension values. As the SWT in the root zone was maintained close to the setup threshold plus 20% tolerance for at least 90% of the evaluation period, the performance of the controllers was considered satisfactory. The proposed controller was shown to be functional and was operated effectively for an SWT range of up to 30 kPa, which is commonly encountered under high-frequency irrigation conditions.

Irrigation and ground cover management effect on soil temperature in a mature peach orchard

1993 ◽  
Vol 73 (3) ◽  
pp. 857-870 ◽  
Author(s):  
C. S. Tan ◽  
R. E. C. Layne
Keyword(s):  
Soil Temperature ◽  
Snow Cover ◽  
Air Temperature ◽  
Prunus Persica ◽  
Ground Cover ◽  
Soil Surface ◽  
Soil Temperatures ◽  
Peach Orchard ◽  
Management Effect ◽  
Minimum Air Temperature

The purpose of this study was to assess the effect of two irrigation (trickle vs. no irrigation) and two ground cover treatments (temporary cover vs. permanent sod) on soil temperature in a mature peach [Prunus persica (L.) Batsch] orchard on Fox sand. The soil temperatures at the surface, 5, 10 and 20 cm depths were monitored continuously all-year during 1987 and 1988. Irrigation reduced the fluctuations in soil temperature during summer and winter. The average daily soil temperature in nonirrigated plots during the summer was as high as 34 °C at the soil surface and 28 °C at the 20-cm depth, while corresponding temperatures in irrigated plots were 28 and 26 °C, respectively. The average daily soil temperature in nonirrigated plots without snow cover during the winter was −12 °C at the soil surface and −5 °C at the 20-cm depth, while corresponding temperatures in irrigated plots were −6 and −1 °C, respectively. The effect of irrigation on soil temperature was greatly diminished by snow cover. The soil temperatures at all depths remained around 0 to −2 °C for both nonirrigated and irrigated plots under snow cover, even when the minimum air temperature dropped to −15 °C. The permanent sod cover provided some protection against cold although this effect was masked by snow cover. In the summer, the permanent sod cover reduced average daily soil temperature by 1.5 and 1 °C at the 10 and 20 cm depths. Key words: Prunus persica, snow cover, Fox sand

scholarly journals ADAPTAÇÃO E AVALIAÇÃO DE EVAPOTRANSPIRÔMETROS PARA A OBTENÇÃO DO COEFICIENTE DE CULTURA BASAL (kcb) DO FEIJOEIRO (Phaseolus vulgaris L.)

Irriga ◽  
1998 ◽  
Vol 3 (3) ◽  
pp. 73-80 ◽  
Author(s):  
Gerson Araujo de Medeiros ◽  
Flávio Bussmeyer Arruda
Keyword(s):  
Phaseolus Vulgaris ◽  
Soil Water ◽  
Crop Coefficient ◽  
Soil Surface ◽  
High Water ◽  
Soil Evaporation ◽  
Phaseolus Vulgaris L ◽  
Soil Water Tension ◽  
Water Tension ◽  
E Mail

ADAPTAÇÃO E AVALIAÇÃO DE EVAPOTRANSPIRÔMETROS PARA A OBTENÇÃO DO COEFICIENTE DE CULTURA BASAL (kcb) DO FEIJOEIRO (Phaseolus vulgaris L.)  Gerson Araujo de MedeirosDepartamento de Água e Solo, Faculdade de Engenharia Agrícola, UNICAMP, C. P. 6011, CEP 13.081-490, Campinas-SP. E-mail: [email protected] Bussmeyer ArrudaSeção de Irrigação e Drenagem, Instituto Agronômico, C. P. 28, CEP 13.001-970, Campinas - São Paulo. E-mail: [email protected]  1 RESUMO O estudo do coeficiente de cultura (kc) tem ganho grande impulso ao seu entendimento e estimativa, quando feito o seu desmembramento em coeficiente de cultura basal (kcb), dependente do desenvolvimento da planta, em um coeficiente solo-planta (ka), dependente do déficit de água no solo, e um coeficiente relacionado ao molhamento da superfície do solo (ks). Uma avaliação das condições de solo e planta foi realizada em quatro evapotranspirômetros de nível freático constante e em um experimento de campo com feijoeiro semanalmente irrigado sob duas densidades de plantio. O trabalho foi conduzido no Instituto Agronômico, Campinas, no período de agosto a novembro de 1994, em um solo argiloso. A fim de se evitar a evaporação direta do solo foi aplicada sobre a superfície de cada evapotranspirômetro uma camada de 1 cm de areia sob uma outra de 1 cm do solo original da área. Observações visuais, crescimento de planta e monitoramento da tensão de água no solo nas profundidades de 5 e 10 cm  nos evapotranspirômetros, mostraram que a tensão nunca excedeu a 10 kPa em ambas as profundidades. A resistência estomática, nos evapotranspirômetros, variou de 0,4 a 1,0 s.cm-1, durante a maior parte do ciclo, excetuando-se a fase de senescência, nas condições de cultura irrigada essa variação foi de 0,5 a 2,7 s.cm-1. Desta forma, as condições exigidas para a obtenção do coeficiente de cultura basal, como recomendadas por Wright (1981), foram satisfeitas, e nas condições de campo essas não se mantiveram, mesmo em feijoeiro irrigado. UNITERMOS : coeficiente de cultura, evapotranspirômetro, evapotranspiração, feijoeiro.  MEDEIROS, G. A., ARRUDA, F. B. Adaptation and evaluation of evapotranspirometer to determine the basal crop coefficient (kcb) of beans.  2 ABSTRACT Crop coefficient (kc) studies has gained a better understanding when it was decomposed in basal crop coefficient (kcb), dependent on crop development, in a soil-plant coefficient (ka), dependent on soil water deficit, and in a coefficient related to soil surface wetting (ks). An evaluation of soil and plant conditions was performed in a four constant water table type of evapotranspirometer and in a field experiment with two planting population densities of beans weekly irrigated (60 kPa at 15 cm). The work was conducted in the Institute Agronomico, Campinas, SP, from August to November of 1994, in a clayed tropical soil. In order to avoid direct soil evaporation it was applied an 1 cm layer of sand below an other 1 cm of original soil on surface of each evapotranspirometer. Visual observations, plant growth and monitoring soil water tension at 5 cm and 10 cm in the evapotranspirometers showed that tension never exceeded 10 kPa at both positions. Leaf stomata resistance of evapotranspirometer plants ranged from 0.4 to 1.0 s.cm-1 most of the crop life compared to 0.5 to 2.7 s.cm-1 of field irrigated plants. It was concluded that the evapotranspirometers were able to maintain a high water supply to a crop with reduced direct soil evaporation, as recommended by Wright (1981), to determine basal crop coefficient, a situation rather difficult to ascertain in the field even for irrigated beans. KEY-WORDS: crop coefficient, evapotranspirometer, evapotranspiration, bean.

Citrus Carbohydrate Levels were Related to Irrigation Frequency but Not Arbuscular Mycorrhizal Fungal (AMF) Inoculum

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498a-498
Author(s):  
Matthew W. Fidelibus ◽  
Chris A. Martin
Keyword(s):  
Soil Water ◽  
Arbuscular Mycorrhizal ◽  
Irrigation Frequency ◽  
Soil Water Tension ◽  
Root Starch ◽  
Carbohydrate Levels ◽  
Amf Communities ◽  
Sugar Levels ◽  
Shoot Mass ◽  
Water Tension

Sugar and starch concentrations in leaves and roots of Citrus volkameriana Tan and Pasq were measured in response to irrigation frequency and AMF inoculum. Non-mycorrhizal seedlings were treated with a soil inoculum from one of five different communities of AMF; two AMF communities from Arizona citrus orchard soils, and three communities from undisturbed desert soils. Plants were assigned to frequent (soil water tension > –0.01 MPa) or infrequent (soil water tension > –0.06 MPa) irrigation cycles and were container-grown in a glasshouse for 4 months before tissues were analyzed. Fungal inoculum source did not affect shoot or root carbohydrate levels. Plants grown under high irrigation frequency had increased leaf and root starch levels and increased root sugar levels compared with those under low irrigation frequencies. High irrigation frequency also increased shoot mass.

scholarly journals Seasonal dynamics of methane emissions from a subarctic fen in the Hudson Bay Lowlands

2013 ◽  
Vol 10 (7) ◽  
pp. 4465-4479 ◽  
Author(s):  
K. L. Hanis ◽  
M. Tenuta ◽  
B. D. Amiro ◽  
T. N. Papakyriakou
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Growing Season ◽  
Near Surface ◽  
Growing Seasons ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Surface Soil Temperature ◽  
Filling Method ◽  
Highly Correlated

Abstract. Ecosystem-scale methane (CH4) flux (FCH4) over a subarctic fen at Churchill, Manitoba, Canada was measured to understand the magnitude of emissions during spring and fall shoulder seasons, and the growing season in relation to physical and biological conditions. FCH4 was measured using eddy covariance with a closed-path analyser in four years (2008–2011). Cumulative measured annual FCH4 (shoulder plus growing seasons) ranged from 3.0 to 9.6 g CH4 m−2 yr−1 among the four study years, with a mean of 6.5 to 7.1 g CH4 m−2 yr−1 depending upon gap-filling method. Soil temperatures to depths of 50 cm and air temperature were highly correlated with FCH4, with near-surface soil temperature at 5 cm most correlated across spring, fall, and the shoulder and growing seasons. The response of FCH4 to soil temperature at the 5 cm depth and air temperature was more than double in spring to that of fall. Emission episodes were generally not observed during spring thaw. Growing season emissions also depended upon soil and air temperatures but the water table also exerted influence, with FCH4 highest when water was 2–13 cm below and lowest when it was at or above the mean peat surface.

scholarly journals Effects of Irrigation Regimes on Yield and Water Use by Sweetpotato

1990 ◽  
Vol 115 (5) ◽  
pp. 712-714 ◽  
Author(s):  
Doyle A. Smittle ◽  
Melvin R. Hall ◽  
James R. Stansell
Keyword(s):  
Water Stress ◽  
Soil Water ◽  
Water Use ◽  
Ipomoea Batatas ◽  
Regression Equations ◽  
Marketable Yield ◽  
Water Regimes ◽  
Soil Water Tension ◽  
Water Tension ◽  
Storage Root Development

Sweetpotatoes [Ipomoea batatas (L.) Lam cv. Georgia Jet] were grown on two soil types in drainage lysimeters under controlled soil water regimes during 1982 and 1983. Water regimes consisted of irrigating the sweetpotatoes throughout growth when soil water tension at 23 cm exceeded 25, 50, or 100 kPa or by allowing a 100-kPa water stress before root enlargement, during early root enlargement, or throughout root enlargement. Water use and marketable yields were greater when sweetpotatoes were grown on a Tifton loamy sand (fine loamy, siliceous, thermic, Plinthitic Paleudult) than when grown on a Bonifay sand (loamy, siliceous, thermic, Grossarenic, Plinthitic Paleudult). Water use, marketable yield, and yield of U.S. #1 grade roots generally decreased when soil water tensions exceeded 25 kPa before irrigation, although soil water stress of 100 kPa during storage root development did not significantly affect yield. Regression equations are provided to describe the relationships of water use to plant age and to compute daily evapotranspiration: pan evaporation ratios (crop factors) for sweetpotatoes irrigated at 25, 50, and 100 kPa of soil water tension.

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