623 Does the Aquadome Ameliorate Diural Fluctuations

A major limitation to plant growth in spring is low night temperatures. A variety of plant protection systems have been developed to keep the temperatures around the plant warmer than the ambient air. One system that has been developed for use with individual plants is a double walled stiff plastic tent. The space between the walls can be either filled with water or air. The top of the tent can be either open or closed. The objective of this investigation is to quantify the effect of these protection systems under controlled environmental conditions. Two wash-tubs filled with wet soil were placed in a controlled environment growth chamber. One tent was placed on the soil surface of each tub. The chamber was programmed to simulate a cold night. Temperatures started at 20 °C and then decreased to –5 °C at a rate of about 4 °C/h. During this time, ambient air temperature, jacket temperature, soil temperature, and air inside the tent was measured continuously with self-contained data loggers. Water filled tents delayed the time it took for the inside temperature to reach the outside temperature by 2 hours. There was not apparent effect on soil temperature. The effect of water vs. air-filled jackets and the effect of capping the top will also be presented.

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Effects of Soil Temperature, Seed Depth, and Cyanazine on Giant Foxtail (Setaria faberi) and Velvetleaf (Abutilon theophrasti) Seedling Development

Weed Science ◽

10.1017/s0043174500071484 ◽

1991 ◽

Vol 39 (2) ◽

pp. 204-209 ◽

Cited By ~ 25

Author(s):

Thomas C. Mester ◽

Douglas D. Buhler

Keyword(s):

Soil Temperature ◽

Seedling Survival ◽

Soil Surface ◽

Seedling Development ◽

Controlled Environment ◽

Weed Population ◽

Setaria Faberi ◽

Giant Foxtail ◽

Soil Temperatures ◽

Initial Seed

Controlled-environment experiments were conducted to determine the effects of soil temperatures of 5 to 20 C, seed depths of 0 to 6 cm, and above- or below-seed cyanazine placement on germination and seedling development of giant foxtail and velvetleaf. Giant foxtail did not germinate at 5 C and failed to emerge from 6 cm deep within 21 days at 10 C. Increasing soil temperature above 10 C increased giant foxtail germination and emergence. Velvetleaf germinated at 5 C but did not emerge within 21 days. Velvetleaf emerged within 21 days from soil depths of 2 to 6 cm at soil temperatures of 10, 15, and 20 C. Giant foxtail and velvetleaf seed germinated on a soil surface kept moist by mulch or frequent watering. Giant foxtail seedling survival was 100% after germination on the soil surface. Velvetleaf often failed to become established; only 28% of the velvetleaf that germinated at 20 C survived. Injury to giant foxtail by cyanazine increased with increasing soil temperatures and decreasing seed depths. Cyanazine placement above or below the seed did not have a consistent effect on giant foxtail injury. Cyanazine placed above the seed was more injurious to velvetleaf than placement below at 15 and 20 C. Differential responses of giant foxtail and velvetleaf seed germination and seedling survivability to initial seed depth appears to be a major factor in weed population shifts when tillage is reduced or eliminated.

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Identification of soil-cooling rains in southern France from soil temperature and soil moisture observations

10.5194/acp-2018-929 ◽

2018 ◽

Author(s):

Sibo Zhang ◽

Catherine Meurey ◽

Jean-Christophe Calvet

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Land Surface ◽

Soil Surface ◽

Ambient Air ◽

Surface Energy Budget ◽

Cooling Effect ◽

Rainfall Events ◽

Southern France ◽

Oceanic Climate

Abstract. In this study, the frequency and intensity of soil-cooling rains is assessed using in situ observations of atmospheric and soil profile variables in southern France. Rainfall, soil temperature and topsoil volumetric soil moisture (VSM) observations, measured every 12 minutes at 21 stations of the SMOSMANIA (Soil Moisture Observing System – Meteorological Automatic Network Integrated Application) network, are analyzed over a time period of 9 years, from 2008 to 2016. The spatial and temporal statistical distribution of the observed rainfall events presenting a marked soil-cooling effect is investigated. It is observed that the soil temperature at a depth of 5 cm can decrease by as much as 6.5 ºC in only 12 minutes during a soil-cooling rain. We define marked soil-cooling rains as rainfall events triggering a drop in soil temperature at a depth of 5 cm larger than 1.5 °C in 12 minutes. Under Mediterranean and Mediterranean-mountain climates, it is shown that such events occur up to nearly 3 times a year, and about once a year on average. This frequency decreases to about once every 3.5 years under semi-oceanic climate. Under oceanic climate, such pronounced soil-cooling rains are not observed over the considered period of time. Rainwater temperature is estimated for 13 cases of marked soil-cooling rains using observed changes within 12 min in soil temperature at a depth of 5 cm, together with soil thermal properties and changes in VSM. On average, the estimated rainwater temperature is generally lower than the observed ambient air temperature, wet-bulb temperature, and topsoil temperature at a depth of 5 cm, with mean differences of −5.1 ºC, −3.8 ºC, and −11.1 ºC, respectively. The most pronounced differences are attributed to hailstorms or to hailstones melting before getting to the soil surface. Ignoring this cooling effect can introduce biases in land surface energy budget simulations.

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Identification of soil-cooling rains in southern France from soil temperature and soil moisture observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-5005-2019 ◽

2019 ◽

Vol 19 (7) ◽

pp. 5005-5020

Author(s):

Sibo Zhang ◽

Catherine Meurey ◽

Jean-Christophe Calvet

Keyword(s):

Soil Moisture ◽

Soil Temperature ◽

Land Surface ◽

Soil Surface ◽

Ambient Air ◽

Surface Energy Budget ◽

Cooling Effect ◽

Rainfall Events ◽

Southern France ◽

Oceanic Climate

Abstract. In this study, the frequency and intensity of soil-cooling rains is assessed using in situ observations of atmospheric and soil profile variables in southern France. Rainfall, soil temperature, and topsoil volumetric soil moisture (VSM) observations, measured every 12 min at 21 stations of the SMOSMANIA (Soil Moisture Observing System – Meteorological Automatic Network Integrated Application) network, are analyzed over a time period of 9 years, from 2008 to 2016. The spatial and temporal statistical distribution of the observed rainfall events presenting a marked soil-cooling effect is investigated. It is observed that the soil temperature at a depth of 5 cm can decrease by as much as 6.5 ∘C in only 12 min during a soil-cooling rain. We define marked soil-cooling rains as rainfall events triggering a drop in soil temperature at a depth of 5 cm larger than 1.5 ∘C in 12 min. Under Mediterranean and Mediterranean–mountain climates, it is shown that such events occur up to nearly 3 times a year, and about once a year on average. This frequency decreases to about once every 3.5 years under semi-oceanic climate. Under oceanic climate, such pronounced soil-cooling rains are not observed over the considered period of time. Rainwater temperature is estimated for 13 cases of marked soil-cooling rains using observed changes within 12 min in soil temperature at a depth of 5 cm, together with soil thermal properties and changes in VSM. On average, the estimated rainwater temperature is generally lower than the observed ambient air temperature, wet-bulb temperature, and topsoil temperature at a depth of 5 cm, with mean differences of −5.1, −3.8, and −11.1 ∘C, respectively. The most pronounced differences are attributed to hailstorms or to hailstones melting before getting to the soil surface. Ignoring this cooling effect can introduce biases in land surface energy budget simulations.

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Integrating Rowcovers and Soil Amendments for Organic Cucumber Production: Implications on Crop Growth, Yield, and Microclimate

HortScience ◽

10.21273/hortsci.45.4.566 ◽

2010 ◽

Vol 45 (4) ◽

pp. 566-574 ◽

Cited By ~ 12

Author(s):

Ajay Nair ◽

Mathieu Ngouajio

Keyword(s):

Plant Growth ◽

Soil Temperature ◽

Light Transmission ◽

Ambient Air ◽

Crop Growth ◽

Organic Production ◽

Growth Characteristics ◽

Temperate Climate ◽

The Impact ◽

Plant Growth Characteristics

The area of organic production has registered a steady increase over past recent years. Transitioning to organic production is not straightforward and often includes a steep learning curve. Organic growers have to develop strategies to best manage nutrients, pests, and crop growth and yield. Additionally, in regions with temperate climate like the Great Lakes region, weather (especially temperature and solar radiation) plays an important role in crop productivity. Growers routinely use compost for nutrient provisioning and rowcovers for insect exclusion and growth enhancement. The objective of this work was to study the combined effect of rowcovers (with different light transmission) and compost organic cucumber (Cucumis sativus L.) growth and microclimate. Plots were assigned to three rowcover treatments (60% light transmission, 85% light transmission, and uncovered) and two amendment treatments (compost and no compost) in a split-plot factorial design. Data were collected for ambient air and soil temperature, photosynthetically active radiation (PAR), relative humidity, plant growth characteristics, and yield. Rowcovers modified crop microclimate by increasing air and soil temperature and decreasing PAR. There was a marked increase in the growing degree-day accumulations under rowcovers when compared with uncovered treatment. The impact of rowcovers on plant growth was significant. Use of rowcovers increased vine length, flower count, leaf area, leaf count, plant biomass, and total marketable yield. Use of compost in conjunction with rowcovers enhanced the rowcover effect. With the use of compost, there were not many significant differences in plant growth characteristics between rowcover materials; however, as expected, rowcover with 60% transmission was able to trap more heat and reduce light transmission when compared with rowcover with 85% transmission. This study clearly shows the importance of organic amendments, especially compost, in organic vegetable production. Applications of compost enhanced crop growth and also led to higher marketable yields. Results of this study suggest additive effects of rowcover and compost application on organic cucumber production.

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The Impact of Plant Protection Systems on the Productivity of Soybean Varieties under Irrigated Conditions

Scientific and Technical Bulletin of the Institute of Oilseed Crops NAAS ◽

10.36710/ioc-2019-28-11 ◽

2019 ◽

pp. 109-117

Keyword(s):

Plant Protection ◽

Crop Protection ◽

Production Costs ◽

Protection System ◽

Average Weight ◽

The South ◽

Biological Origin ◽

Chemical Protection ◽

Protection Systems ◽

The Impact

The application of preparations of biological origin in the protection system of soybean grown under conditions of intensive irrigated crop rotations conforms to the modern tendencies of science and production development. The use of them contributes to solving ecological, production and social-economic problems. The study presents the three-year research on the efficiency of systems protecting soybean from pests and diseases based on biological and chemical preparations. The research was conducted in typical soil and climate conditions of the South of Ukraine. Zonal agricultural methods and generally accepted research methodology were used. The purpose of the research was to create a soybean protection system based on preparations of biological origin, ensuring high productivity of high-quality products reducing a negative impact of the crop production on the environment. The study emphasizes that, under irrigated conditions of the South of Ukraine, the application of biological preparations has a positive impact on the indexes of growth, development and formation of the elements of soybean yield structure. There was an increase in the crop biological weight by 13.8 % and 22.1 % and the number of seeds per plant rose by 11.6 and 14.6 % as a consequence of eliminating harmful organisms with the plant protection systems. The larger ground mass was formed by medium-ripe varieties Danai and Svyatogor, on which the increase from protection measures was higher. Weight 1000 pcs. the seeds did not undergo significant changes. It is established that the larger seeds were formed by Danaya and Svyatogor varieties, in which the average weight is 1000 pcs. seeds were 142 and 136 g, respectively, while in the variety Diona this figure was 133 g. There was an increase in the height of the lowest pod when the total plant height rose. For medium-ripe varieties was characterized by a higher attachment of beans, where the highest values of this indicator acquired in the variety Svyatogor. The medium maturing soybean variety Danaia formed the maximum yield of 3.23 and 3.35 t/ha respectively, when biological and chemical protection systems were applied. The research establishes that the application of the bio-fungicide Psevdobakterin 2 (2.0 l/ha) in the crop protection system at the beginning of soybean flowering and the bio-fungicide Baktofit (2.5 l/ha) with the bio-insecticide Lepidotsid-BTU (10.0 l/ha) at the beginning of pod formation does not reduce the productivity of the soybean varieties under study considerably, when compared to the application of chemical preparations. The research determines that the soybean protection system under study ensures a decrease in the coefficient of soybean water uptake by 7.2-13.0 %, increasing the total water intake to an inconsiderable degree. Biologization of the soybean crop protection system leads to a reduction in production costs compared to the chemical protection system. Taking into account the needs for the collection of additional products, costs increase by an average of 1 thousand UAH/ha, while for chemical protection systems by 1.8 thousand UAH/ha. At the same time, the cost is reduced by 220-360 UAH/t and the profitability of growing crops is increased by 3.8-7.8 %. There has been a reduction in the burden of pesticides on the environment and the production of cleaner products. This indicates the prospect of using the biofungicides Pseudobacterin 2 and Bactophyte and the bioinsecticide Lepidocid-BTU on soybeans to protect plants from pests.

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Embryo dormancy responses to temperature in capeweed (Arctotheca calendula) seeds

Seed Science Research ◽

10.1079/ssr2002110 ◽

2002 ◽

Vol 12 (3) ◽

pp. 181-191 ◽

Cited By ~ 2

Author(s):

Amanda J. Ellery

Keyword(s):

Soil Temperature ◽

Water Potential ◽

Low Temperatures ◽

Seasonal Changes ◽

Temperature Fluctuation ◽

Soil Surface ◽

Seed Collection ◽

Embryo Dormancy ◽

Response To Temperature ◽

Dormancy Cycles

Changes in embryo dormancy of capeweed [Arctotheca calendula (L.) Levyns.] seeds in response to temperature were investigated to determine the nature of seasonal dormancy cycles. Primary embryo dormancy persisted for 2–3 months after seed collection and was then rapidly relieved when seeds were maintained at temperatures simulating summer soil surface temperatures. Embryo dormancy was also rapidly relieved in seeds maintained at constant temperatures, indicating that a daily temperature fluctuation was not necessary for the relief of embryo dormancy in capeweed. Dormancy relief was maximal at 40°C. Secondary dormancy was induced when seeds were maintained at low temperatures and a water potential of –1.5 MPa, suggesting that the onset of winter may postpone germination until a subsequent autumn. These results indicate that the dormancy cycles observed in capeweed seeds maintained on the soil surface are probably driven by seasonal changes in soil temperature.

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Analytical Model to Predict Nonhomogeneous Soil Temperature Variation

Journal of Solar Energy Engineering ◽

10.1115/1.2870823 ◽

1995 ◽

Vol 117 (2) ◽

pp. 100-107 ◽

Cited By ~ 7

Author(s):

M. Krarti ◽

D. E. Claridge ◽

J. F. Kreider

Keyword(s):

Thermal Properties ◽

Soil Temperature ◽

Temperature Variation ◽

Analytical Model ◽

Soil Surface ◽

Deep Soil ◽

Soil Thermal Properties ◽

Order Of Magnitude ◽

Soil Surface Temperature ◽

Annual Time

This paper presents an analytical model to predict the temperature variation within a multilayered soil. The soil surface temperature is assumed to have a sinusoidal time variation for both daily and annual time scales. The soil thermal properties in each layer are assumed to be uniform. The model is applied to two-layered, three-layered, and to nonhomogeneous soils. In case of two-layered soil, a detailed analysis of the thermal behavior of each layer is presented. It was found that as long as the order of magnitude of the thermal diffusivity of soil surface does not exceed three times that of deep soil; the soil temperature variation with depth can be predicted accurately by a simplified model that assumes that the soil has constant thermal properties.

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