Soil Temperature, Soil Moisture, and Seed Burial Depth Effects on Redstem Filaree (Erodium cicutarium) Emergence

Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 204-207 ◽  
Author(s):  
Robert E. Blackshaw
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Environmental Conditions ◽  
Burial Depth ◽  
Moist Soil ◽  
Seed Burial ◽  
Erodium Cicutarium ◽  
Rate Of Emergence ◽  
Water Contents ◽  
Depth Effects

A study was conducted under controlled environmental conditions to determine the effect of soil temperature, soil moisture, and depth of seed burial on the emergence of redstem filaree. Emergence occurred from 5 to 30 C but was optimal at 5 to 15 C. Redstem filaree emergence was optimal in moist soil with water contents of −0.03 to −0.28 MPa. Emergence progressively decreased as soil moisture was lowered below these levels, with less than 25% emergence attained at −1.53 MPa regardless of soil temperature. Almost no germination was observed in warm (30 C), dry (-1.03 to −1.53 MPa) soils. Rate of emergence was affected more by soil temperature than by moisture. A decrease in temperature from 20 to 5 C increased the time to reach 50% emergence by 6 to 8 d but a decrease in soil moisture from −0.03 to −1.53 MPa increased the time to reach 50% emergence by only 1 to 2 d. Emergence was greatest at soil depths of 1 cm or less. No emergence occurred at depths of 8 cm or below.

Influence of Soil Temperature, Soil Moisture, and Seed Burial Depth on the Emergence of Round-Leaved Mallow (Malva pusilla)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 518-521 ◽  
Author(s):  
Robert E. Blackshaw
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Water Content ◽  
Environmental Conditions ◽  
Control Strategies ◽  
Cultural Control ◽  
Burial Depth ◽  
Moisture Regime ◽  
Seed Burial ◽  
Rate Of Emergence

A study was conducted under controlled environmental conditions to determine the effect of soil temperature, soil moisture, and depth of seed burial on the emergence of round-leaved mallow. Emergence occurred from 5 to 30 C but was optimal at 15 to 20 C. Soil moisture had a greater effect than soil temperature on percentage emergence. Emergence progressively declined below a soil water content of −0.28 MPa, with less than 20% emergence attained at −1.03 to −1.53 MPa. In contrast, rate of emergence of round-leaved mallow was affected more by soil temperature than by moisture. A decrease in temperature from 30 to 5 C increased the time to reach 50% emergence by 10 to 12 days over the moisture regime of this study. Emergence was greatest at depths of 0.5 to 2 cm. No emergence occurred at 8 cm or below. The potential of using the findings of this study to develop cultural control strategies for round-leaved mallow is discussed.

Prediction of evaporation with the CONSEVB simulation-model - an experimental evaluation

Soil Research ◽  
1994 ◽  
Vol 32 (1) ◽  
pp. 45
Author(s):  
HP Cresswell ◽  
DJ Painter ◽  
KC Cameron
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Simulation Model ◽  
Water Content ◽  
Soil Water ◽  
Cost Benefit ◽  
Initial Water ◽  
Input Parameters ◽  
Moisture Characteristic ◽  
Water Contents

The CONSERVB simulation model was evaluated by comparing predictions of evaporation, net radiation, and water and temperature profiles with measured values from a bare, tilled soil in New Zealand conditions. No model calibration was used whatsoever. The assessment included tests of the sensitivity of output to variations (uncertainty) in input parameters. On 18 of the 24 days simulated, evaporation was within 0.5 mm day-1 of the measured means, although that represented less than 20% error on only 6 days. The mean difference between measured and simulated surface soil temperature for the two drying cycles was 1.2 and 1.3�C; most of this error occurred in warm conditions around noon each day. Simulated soil temperature at 0.05 m exceeded measured values during the warmest parts of the day and fell below them at night. Soil temperature prediction was sensitive to the air temperature and solar radiation climatic inputs. Evaporation prediction was sensitive to initial profile water contents, to the soil moisture characteristic and to the unsaturated hydraulic conductivity inputs. An increase in the water content at each matric potential step in the soil moisture characteristic input by a factor of 1.10 resulted in an increase in simulated cumulative evaporation of over 40%. For the prediction of evaporation and soil water content, field effort in the measurement of the soil hydraulic properties and initial water contents (where simulations are short) for model parameterization is likely to give the highest cost-benefit. Very accurate determinations of these input parameters and functions are required for model evaluation. Given the sensitivities, and the uncertainties associated with measurement and prediction of model input parameters, the predictions from CONSERVB have large uncertainties associated with them. Field-measured values of cumulative evaporation were within the range of variation in predicted values that resulted from uncertainty in determination of initial soil water contents alone. CONSERVB is more applicable to an operations research modelling approach than to prediction of evaporation and surface water contents in specific conditions.

SEEDLING BLIGHT, A FUSARIAL DISEASE OF ASPARAGUS

1955 ◽  
Vol 33 (5) ◽  
pp. 374-400 ◽  
Author(s):  
K. M. Graham
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Disease Incidence ◽  
Basal Medium ◽  
Root Tip ◽  
Seedling Blight ◽  
Rate Of Emergence ◽  
Emergence Phase ◽  
Embryonic Region ◽  
Rapid Emergence

Incidence of seedling blight in Ontario can be correlated with proximity of mature plantations or with the presence of debris from a previous asparagus crop. As the disease was detected on seedlings grown in soil from "volunteer" plants growing in isolated habitats, the pathogen is considered to be indigenous. The pathogen penetrates directly into the embryonic region of the root tip, or through stomata on the hypocotyl, and colonizes the host both intercellularly and intracellularly. Its limitation to the cortex is regarded as unusual among the parasitic fusaria, which are mainly vascular. The fungus was identified as Fusarium oxysporum sensu Snyder & Hansen var. redolens (Wr.) Gordon. In comparison with F. moniliforme Sheldon, found to cause a root tip necrosis of asparagus seedlings, the cortical Fusarium produced less growth on basal medium plus cellulose but more growth on sucrose, and showed a greater ability to hydrolyze starch. Differing nutrient preferences are suggested as one explanation for the localized types of colonization exhibited by these two fusaria. The optimum soil temperature for disease incidence was established at 25°-30 °C. The effect of temperatures above 30 °C. is considered to be twofold: (1) inhibiting growth of the pathogen and (2) permitting the host to escape by inducing its more rapid emergence. Below 20 °C, the pre-emergence phase of the disease is favored by a retardation of the rate of emergence. Both low and high levels of soil moisture retard emergence and favor pre-emergence blight. Under greenhouse conditions, incidence of the disease usually increased more rapidly when leguminous rather than nonleguminous residues were present in the soil and there was some evidence that the saprophytic growth of the pathogen was more profuse on certain nonliving substrates.

The temperature and moisture regime of charcoal-enriched land use legacy soils

2020 ◽  
Author(s):  
Anna Schneider ◽  
Florian Hirsch ◽  
Alexander Bonhage ◽  
Alexandra Raab ◽  
Thomas Raab
Keyword(s):  
Thermal Conductivity ◽  
Land Use ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Bulk Density ◽  
Forest Soils ◽  
Moisture Regime ◽  
Seasonal Temperature ◽  
Water Contents ◽  
Soil Temperature And Moisture

<p>The stratigraphy and properties of soils can be significantly altered by past land use, even in areas that have been continuously used for forestry. Soils on relict charcoal hearths (RCHs) are a widespread example of such a pedological legacy of past forest use. RCH soils occur in many forest areas and receive increasing attention as model sites to study long-term effects of soil amendment with biochars, however, their physical properties have hardly been studied. The objective of our study was to characterize the soil temperature and moisture regime of RCH soils through comparison to reference forest soils on sandy substrates in woodlands in Brandenburg, Germany. We combined laboratory analyses of bulk density, pore size distribution, thermal conductivity and saturated hydraulic conductivity with sensor-based monitoring of soil temperature, moisture contents and matric potentials. </p><p>The results of laboratory analysis reveal high soil organic matter (SOM) contents, a low bulk density and high porosity of the RCH substrates. Associated with this RCH specific soil structure, RCHs exhibit clearly lower thermal conductivity. However, the higher total porosity of RCH substrates does not necessarily imply higher water retention and plant-available water contents in the RCH soils than in the topsoil horizons of undisturbed forest soils.  The monitoring results reveal distinct differences between the temperature regimes of the RCH and reference profiles, with the RCH soil exhibiting higher daily and seasonal temperature variations within the topmost horizon, but lower variations in deeper parts of the profiles. Soil moisture monitoring shows higher water contents in RCH soils under relatively wet conditions and lower water contents under dry conditions, and increased spatial variation in soil moisture in RCH soils. Overall, the results show increased spatial and temporal variability of soil temperature and moisture on RCHs, which implies an increased variability in ecological site conditions in historic charcoal production areas.</p><p> </p>

scholarly journals Effects of soil temperature and moisture on methane uptakes and nitrous oxide emissions across three different ecosystem types

2013 ◽  
Vol 10 (1) ◽  
pp. 927-965 ◽  
Author(s):  
G. J. Luo ◽  
R. Kiese ◽  
B. Wolf ◽  
K. Butterbach-Bahl
Keyword(s):  
Nitrous Oxide ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Tropical Forest ◽  
Environmental Conditions ◽  
Temperate Forest ◽  
Explanatory Power ◽  
Nitrous Oxide Emissions ◽  
Forest Site ◽  
Methane Uptake

Abstract. In this paper, we investigate similarities of effects of soil environmental drivers on year-round daily soil fluxes of nitrous oxide and methane for three distinct semi-natural or natural ecosystems: temperate spruce forest, Germany; tropical rain forest, Queensland, Australia; and ungrazed semi-arid steppe, Inner Mongolia, China. Annual cumulative fluxes of nitrous oxide and methane varied markedly among ecosystems, with nitrous oxide fluxes being highest for the tropical forest site (tropical forest: 0.96 kg N ha−1yr−1; temperate forest: 0.67 kg N ha−1yr−1; steppe: 0.22 kg N ha−1yr−1), while rates of soil methane uptake were approximately equal for the temperate forest (3.45 kg C ha−1yr−1) and the steppe (3.39 kg C ha−1yr−1), but lower for the tropical forest site (2.38 kg C ha−1yr−1). In order to allow for cross-site comparison of effects of changes in soil moisture and soil temperature on fluxes of methane and nitrous oxide, we used a normalization approach. Data analysis with normalized data revealed that across sites, optimum rates of methane uptake are found at environmental conditions representing approximately average site environmental conditions. This might have rather important implications for understanding effects of climate change on soil methane uptake potential, since any shift in environmental conditions is likely to result in a reduction of soil methane uptake ability. For nitrous oxide, our analysis revealed expected patterns: highest nitrous oxide emissions under moist and warm conditions and large nitrous oxide fluxes if soils are exposed to freeze-thawing effects at sufficient high soil moisture contents. However, the explanatory power of relationships of soil moisture or soil temperature to nitrous oxide fluxes remained rather poor (≤ 0.36). When combined effects of changes in soil moisture and soil temperature were considered, the explanatory power of our empirical relationships with regard to temporal variations in nitrous oxide fluxes were at maximum about 50%. This indicates that other controlling factors such as N and C availability or microbial community dynamics might exert a significant control on the temporal dynamic of nitrous oxide fluxes. Though underlying microbial processes such as nitrification and denitrification are sensitive to changes in the environmental regulating factors, important regulating factors like moisture and temperature seem to have both synergistic and antagonistic effects on the status of other regulating factors. Thus we cannot expect a~simple relationship between them and the pattern in the rate of emissions, associated with denitrification or nitrification in the soils. In conclusion, we hypothesize that our approach of data generalization may prove beneficial for the development of environmental response models which can be used across sites, and which are needed to help better understanding climate change feedbacks on biospheric sinks or sources of nitrous oxide and methane.

scholarly journals Effects of soil temperature and moisture on methane uptake and nitrous oxide emissions across three different ecosystem types

2013 ◽  
Vol 10 (5) ◽  
pp. 3205-3219 ◽  
Author(s):  
G. J. Luo ◽  
R. Kiese ◽  
B. Wolf ◽  
K. Butterbach-Bahl
Keyword(s):  
Nitrous Oxide ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Tropical Forest ◽  
Environmental Conditions ◽  
Temperate Forest ◽  
Explanatory Power ◽  
Nitrous Oxide Emissions ◽  
Forest Site ◽  
Methane Uptake

Abstract. In this paper, we investigate similarities of effects of soil environmental drivers on year-round daily soil fluxes of nitrous oxide and methane for three distinct semi-natural or natural ecosystems: temperate spruce forest, Germany; tropical rain forest, Queensland, Australia; and ungrazed semi-arid steppe, Inner Mongolia, China. Annual cumulative fluxes of nitrous oxide and methane varied markedly among ecosystems, with nitrous oxide fluxes being highest for the tropical forest site (tropical forest: 0.96 kg N ha−1 yr−1; temperate forest: 0.67 kg N ha−1 yr−1; steppe: 0.22 kg N ha−1 yr−1), while rates of soil methane uptake were approximately equal for the temperate forest (−3.45 kg C ha−1 yr−1) and the steppe (−3.39 kg C ha−1 yr−1), but lower for the tropical forest site (−2.38 kg C ha−1 yr−1). In order to allow for cross-site comparison of effects of changes in soil moisture and soil temperature on fluxes of methane and nitrous oxide, we used a normalization approach. Data analysis with normalized data revealed that, across sites, optimum rates of methane uptake are found at environmental conditions representing approximately average site environmental conditions. This might have rather important implications for understanding effects of climate change on soil methane uptake potential, since any shift in environmental conditions is likely to result in a reduction of soil methane uptake ability. For nitrous oxide, our analysis revealed expected patterns: highest nitrous oxide emissions under moist and warm conditions and large nitrous oxide fluxes if soils are exposed to freeze–thawing effects at sufficiently high soil moisture contents. However, the explanatory power of relationships of soil moisture or soil temperature to nitrous oxide fluxes remained rather poor (R2 ≤ 0.36). When combined effects of changes in soil moisture and soil temperature were considered, the explanatory power of our empirical relationships with regard to temporal variations in nitrous oxide fluxes were at maximum about 50%. This indicates that other controlling factors such as N and C availability or microbial community dynamics might exert a significant control on the temporal dynamic of nitrous oxide fluxes. Though underlying microbial processes such as nitrification and denitrification are sensitive to changes in the environmental regulating factors, important regulating factors like moisture and temperature seem to have both synergistic and antagonistic effects on the status of other regulating factors. Thus we cannot expect a simple relationship between them and the pattern in the rate of emissions, associated with denitrification or nitrification in the soils. In conclusion, we hypothesize that our approach of data generalization may prove beneficial for the development of environmental response models, which can be used across sites, and which are needed to help achieve a better understanding of climate change feedbacks on biospheric sinks or sources of nitrous oxide and methane.

Germination and emergence of Astrodaucus orientalis (L.) Drude populations influenced by environmental factors and seed burial depth

2021 ◽  
Vol 36 (2) ◽  
pp. 338-347
Author(s):  
Rouhollah Amini ◽  
Atefeh Ebrahimi ◽  
Adel Dabbagh Mohammadi Nasab
Keyword(s):  
Environmental Factors ◽  
Burial Depth ◽  
Seed Burial

Ecological responses of Stipa steppe in Inner Mongolia to experimentally increased temperature and precipitation. 3. Soil respiration

2018 ◽  
Vol 40 (2) ◽  
pp. 153 ◽  
Author(s):  
Xuexia Wang ◽  
Yali Chen ◽  
Yulong Yan ◽  
Zhiqiang Wan ◽  
Ran Chao ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Respiration ◽  
Soil Temperature ◽  
Respiration Rate ◽  
Inner Mongolia ◽  
Growing Season ◽  
Climatic Warming ◽  
Soil Respiration Rate ◽  
Natural Rainfall ◽  
Temperature And Precipitation

The response of soil respiration to simulated climatic warming and increased precipitation was evaluated on the arid–semi-arid Stipa steppe of Inner Mongolia. Soil respiration rate had a single peak during the growing season, reaching a maximum in July under all treatments. Soil temperature, soil moisture and their interaction influenced the soil respiration rate. Relative to the control, warming alone reduced the soil respiration rate by 15.6 ± 7.0%, whereas increased precipitation alone increased the soil respiration rate by 52.6 ± 42.1%. The combination of warming and increased precipitation increased the soil respiration rate by 22.4 ± 11.2%. When temperature was increased, soil respiration rate was more sensitive to soil moisture than to soil temperature, although the reverse applied when precipitation was increased. Under the experimental precipitation (20% above natural rainfall) applied in the experiment, soil moisture was the primary factor limiting soil respiration, but soil temperature may become limiting under higher soil moisture levels.

The Influence of Soil Moisture and Soil Type on the Oviposition Behaviour of the Migratory Grasshopper, Melanoplus sanguinipes (Fabricius)

1965 ◽  
Vol 97 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Roy L. Edwards ◽  
Henry T. Epp
Keyword(s):  
Soil Moisture ◽  
Free Choice ◽  
Melanoplus Sanguinipes ◽  
Moist Soil ◽  
Moist Sand ◽  
Subsurface Soil ◽  
Water Ph ◽  
Dry Soil ◽  
Oviposition Sites ◽  
Different Soils

Abstract Three different soils – sand, loam and clay – at each of three moisture levels – saturated, intermediate, and dry – were offered to female Melanoplus sanguinipes as oviposition sites. When given a free choice the females preferred moist sand to all other oviposition sites and avoided soil that was completely dry. When no moist soil was available, coarse dry soil was preferred to fine dry soil, but the oviposition rate was reduced. The females would probe and dig at random into any of the soil offered but would withhold their eggs temporarily if the subsurface soil was not moist. Soil water pH appeared to have very little influence on the females' acceptance of an oviposition site as egg pods were deposited in soils with a range of pH from 3.0 to 11.6. It is suggested that although the absence of moisture in the soil may affect the distribution of egg-pods in the microhabitat and may reduce the rate of egg-pod production slightly, the temperature prevailing during the oviposition period is perhaps a more important factor in determining the number of egg-pods deposited.

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