THE BIOLOGY OF CANADIAN WEEDS. 2. SPIRAEA LATIFOLIA

Spiraea latifolia (Ait.) Borkh., broad-leaved meadowsweet (Rosaceae), is a weed of pastures, lowbush blueberry (Vaccinium angustifolium Ait. and V. myrtilloides Mich.) fields and cranberry (V. macrocarpon Ait.) bogs of Eastern Canada, especially where soil moisture content is high during the growing season. Where S. latifolia occurs, other vegetation is lacking or depressed. Much time is lost in harvesting lowbush blueberries due to jamming of the S. latifolia stems among the tines of the rake or in cranberries due to mechanical damage to the harvesters. In Canada, S. latifolia occurs in Newfoundland, Prince Edward Island, Nova Scotia, New Brunswick, Quebec, Ontario, and Manitoba.

Download Full-text

Difference in Canopy and Air Temperature as an Indicator of Grassland Water Stress

Soil and Water Research ◽

10.17221/6514-swr ◽

2013 ◽

Vol 1 (No. 4) ◽

pp. 127-138 ◽

Cited By ~ 2

Author(s):

Duffková Renata

Keyword(s):

Soil Moisture ◽

Water Stress ◽

Moisture Content ◽

Air Temperature ◽

Temperature Difference ◽

Soil Moisture Content ◽

Growing Season ◽

Plant Residues ◽

Dead Plant ◽

Linear Correlations

In 2003–2005 in conditions of the moderately warm region of the Třeboň Basin (Czech Republic) the difference between canopy temperature (Tc) and air temperature at 2 m (Ta) was tested as an indicator of grassland water stress. To evaluate water stress ten-minute averages of temperature difference Tc–Ta were chosen recorded on days without rainfall with intensive solar radiation from 11.00 to 14.00 CET. Water stress in the zone of the major portion of root biomass (0–0.2 m) in the peak growing season (minimum presence of dead plant residues) documented by a sudden increase in temperature difference, its value 5–12°C and unfavourable canopy temperatures due to overheating (> 30°C) was indicated after high values of suction pressure approaching the wilting point (1300 kPa) were reached. High variability of temperature difference in the conditions of sufficient supply of water to plants was explained by the amount of dead plant residues in canopy, value of vapour pressure deficit (VPD), actual evapotranspiration rate (ETA) and soil moisture content. At the beginning of the growing season (presence of dead plant residues and voids) we proved moderately strong negative linear correlations of Tc–Ta with VPD and Tc–Ta with ETA rate and moderately strong positive linear correlations of ETA rate with VPD. In the period of intensive growth (the coverage of dead plant residues and voids lower than 10%) moderately strong linear correlations of Tc–Ta with VPD and multiple linear correlations of Tc–Ta with VPD and soil moisture content at a depth of 0.10–0.40 m were demonstrated.

Download Full-text

Inter-annual variation of carbon uptake by a plantation oak woodland in south-eastern England

Biogeosciences ◽

10.5194/bg-9-5373-2012 ◽

2012 ◽

Vol 9 (12) ◽

pp. 5373-5389 ◽

Cited By ~ 33

Author(s):

M. Wilkinson ◽

E. L. Eaton ◽

M. S. J. Broadmeadow ◽

J. I. L. Morison

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Eddy Covariance ◽

Carbon Balance ◽

Annual Variation ◽

Soil Moisture Content ◽

Growing Season ◽

Co2 Uptake ◽

Growing Season Length ◽

Net Co2 Uptake

Abstract. The carbon balance of an 80-yr-old deciduous oak plantation in the temperate oceanic climate of the south-east of Great Britain was measured by eddy covariance over 12 yr (1999–2010). The mean annual net ecosystem productivity (NEP) was 486 g C m−2 yr−1 (95% CI of ±73 g C m−2 yr−1), and this was partitioned into a gross primary productivity (GPP) of 2034 ± 145 g C m−2 yr−1, over a 165 (±6) day growing season, and an annual loss of carbon through respiration and decomposition (ecosystem respiration, Reco) of 1548 ± 122 g C m−2 yr−1. Although the maximum variation of NEP between years was large (333 g C m−2 yr−1), the ratio of Reco/GPP remained relatively constant (0.76 ± 0.02 CI). Some anomalies in the annual patterns of the carbon balance could be linked to particular weather events, such as low summer solar radiation and low soil moisture content (values below 30% by volume). The European-wide heat wave and drought of 2003 did not reduce the NEP of this woodland because of good water supply from the surface-water gley soil. The inter-annual variation in estimated intercepted radiation only accounted for ~ 47% of the variation in GPP, although a significant relationship (p < 0.001) was found between peak leaf area index and annual GPP, which modified the efficiency with which incident radiation was used in net CO2 uptake. Whilst the spring start and late autumn end of the net CO2 uptake period varied substantially (range of 24 and 27 days respectively), annual GPP was not related to growing season length. Severe outbreaks of defoliating moth caterpillars, mostly Tortrix viridana L. and Operophtera brumata L., caused considerable damage to the forest canopy in 2009 and 2010, resulting in reduced GPP in these two years. Inter-annual variation in the sensitivity of Reco to temperature was found to be strongly related to summer soil moisture content. The eddy covariance estimates of NEP closely matched mensuration-based estimates, demonstrating that this forest was a substantial sink of carbon over the 12-yr measurement period.

Download Full-text

The effect of rainfall and extensive use of grasslands on water regime

Plant Soil and Environment ◽

10.17221/4205-pse ◽

2011 ◽

Vol 48 (No. 3) ◽

pp. 89-95

Author(s):

R. Duffková

Keyword(s):

Land Use ◽

Soil Moisture ◽

Moisture Content ◽

Water Regime ◽

Soil Moisture Content ◽

Growing Season ◽

Water Runoff ◽

Botanical Composition ◽

Significant Difference ◽

Determinant Factor

 Water regimes of extensively used grasslands (one cut per year, two cuts per year, no cut, mulching) were determined and compared by drainage lysimeters in 1998–2000. Although the botanical composition and yields of experimental swards were different, there was no statistically significant difference in their water regime (only the soil moisture content of no-cut variant was significantly higher than in other variants). A determinant factor for the water regime of grasslands (GR) is the sum of rainfall over the growing season while the GR water regime is influenced by land use immediately after the cut. Water runoff from the soil profile 0.0–0.60 m (water supply to the groundwater level) was found to be negligible in the growing season, a substantial groundwater recharge occurs in an off-season period and/or at the beginning of growing season. Mulching was not proved to reduce evaporation. The best type of management providing for the economical water regime appears to be a one-cut variant. Relationships between botanical composition and GR water regime are also described.

Download Full-text

REGRESSIONS FOR ESTIMATING STRAW YIELDS AND N AND P CONTENTS OF SPRING WHEAT AND N MINERALIZATION IN A BROWN LOAM SOIL

Canadian Journal of Soil Science ◽

10.4141/cjss88-031 ◽

1988 ◽

Vol 68 (2) ◽

pp. 337-344 ◽

Cited By ~ 3

Author(s):

C. A. CAMPBELL ◽

R. P. ZENTNER ◽

F. SELLES

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Spring Wheat ◽

N Mineralization ◽

Soil Moisture Content ◽

N Uptake ◽

Growing Season ◽

Net N Mineralization ◽

Loam Soil ◽

Growing Season Precipitation

Data from an 18-yr crop rotation study carried out on a Brown loam soil at Swift Current, Saskatchewan, were used to estimate equations that relate spring wheat straw yields, and N and P content of grain and straw to moisture use (MU). Moisture use was defined as soil moisture content in 0- to 120-cm depth at seeding, less soil moisture content at harvest, plus growing season precipitation. Grain yields were also related to straw yields and to N content of the straw. Potential net N mineralization (Nmin) in summerfallow (periods during the growing season with negative Nmin omitted) was related (r = 0.74**) to precipitation received during the spring to fall period. An attempt to relate apparent net Nmin (determined by N balance) in cropped systems to growing season precipitation or to MU was not successful. Highly significant linear regressions were obtained for straw yields, grain N and P contents vs. MU, and for grain yield vs. straw yield (r = 0.66** – 0.83**), but the other relationships were less reliable (r = 0.41** – 0.55**) though still significant. We discussed how these relationships might be used to estimate fertilizer N requirements, for examining N immobilization-mineralization, and for estimating residue sufficiency for erosion control on summerfallowed land. Key words: Straw:grain ratio, N uptake, P uptake, crop residues, N mineralization

Download Full-text

WATER TABLE BEHAVIOR AND SOIL MOISTURE CONTENT DURING THE WINTER

Canadian Journal of Soil Science ◽

10.4141/cjss70-047 ◽

1970 ◽

Vol 50 (3) ◽

pp. 361-366 ◽

Cited By ~ 1

Author(s):

J. C. van SCHAIK ◽

E. RAPP

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Water Table ◽

Soil Moisture Content ◽

Growing Season ◽

Grass Cover ◽

Irrigation Project ◽

Southern Alberta

Water table recession in an irrigation project in southern Alberta was compared with moisture translocation in covered lysimeters during two winters. Upward translocation to the surface 60 cm during one winter amounted to 1 to 2 cm of water in dry soils having a grass cover, and 2 to 2.3 cm in moist soils with no vegetation. Observations between growing season and freeze-up indicated that a considerable amount of water may drain downward. The upper 30 cm of soil generally is not influenced by upward translocation if the soil is dry before freeze-up.

Download Full-text

THE BIOLOGY OF CANADIAN WEEDS.: 1. Kalmia angustifolia L.

Canadian Journal of Plant Science ◽

10.4141/cjps73-168 ◽

1973 ◽

Vol 53 (4) ◽

pp. 865-873 ◽

Cited By ~ 11

Author(s):

IVAN V. HALL ◽

LLOYD P. JACKSON ◽

C. FRED EVERETT

Keyword(s):

Nova Scotia ◽

New Brunswick ◽

Prince Edward Island ◽

Biological Information ◽

Eastern Canada ◽

Kalmia Angustifolia ◽

Lowbush Blueberry

This contribution on Kalmia angustifolia L., sheep-laurel (Ericaceae), is part of a series that presents biological information on plants that are weedy in Canada. Kalmia angustifolia is a weed of lowbush blueberry fields and pastures in eastern Canada. It occurs in Newfoundland, Prince Edward Island, Nova Scotia, New Brunswick, Quebec, and Ontario.

Download Full-text

Evaluation of DualEM-II sensor for soil moisture content estimation in the potato fields of Atlantic Canada

Plant Soil and Environment ◽

10.17221/72/2019-pse ◽

2019 ◽

Vol 65 (No. 6) ◽

pp. 290-297 ◽

Cited By ~ 3

Author(s):

Aitazaz Farooque ◽

Mahnaz Zare ◽

Qamar Zaman ◽

Farhat Abbas ◽

Melanie Bos ◽

...

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Precision Agriculture ◽

Prince Edward Island ◽

Soil Moisture Content ◽

Root Zone ◽

Time Domain Reflectometry ◽

Atlantic Canada ◽

Significant Difference ◽

Non Destructive

The conventional gravimetric methods of estimating soil moisture content (θ) are laborious, time-consuming, and destructive to agricultural fields. We evaluated the performance of DualEM-II sensor in non-destructive way of θ prediction and for predicting θ variations within potato fields in Atlantic Canada. Values of θ were measured from four potato fields in New Brunswick and Prince Edward Island using a pre-calibrated (R2 = 0.98) time domain reflectometry (TDR) from root zone of potato tubers under grid sampling arrangements. Horizontal co-planar (HCP) and perpendicular co-planar (PRP) readings were taken using DualEM-II sensor from the same locations of θ measurements. There was a better correlation between PRP and θ (r: 0.64–0.83) was calculated than between HCP and θ (r: 0.41–0.79). There was no significant difference (R2: 0.60–0.69; RMSE (root mean square error): 2.32–4.02) between the θ values measured with TDR (θM) and those predicted with DualEM-II (θP) confirming that the use of electromagnetic induction technique, evaluated during this study, is labor saving, quick, non-destructive, and accurate and can be considered a precision agriculture tool for efficiently managing soil water in potato fields.

Download Full-text

Previous and Current Crop Effects on Early-Season Root Growth and Growing Season’s Soil Moisture Under Dryland Agriculture in Temperate Climate

Journal of Agricultural Science ◽

10.5539/jas.v13n5p50 ◽

2021 ◽

Vol 13 (5) ◽

pp. 50

Author(s):

Kabal S. Gill ◽

Surinder K. Jalota

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Root Growth ◽

Soil Moisture Content ◽

Growing Season ◽

Temperate Climate ◽

Residual Soil ◽

Dryland Agriculture ◽

Early Season ◽

Growing Seasons

Understanding the root growth and changes in soil moisture content during the growing season for dryland agriculture crops can improve crop production. It was hypothesized that early-season root growth might be influenced by previous crop and current crops, and soil moisture content and depletion pattern during the growing season and residual soil moisture may be affected by the crop type. A study was conducted on the early-season root growth of canola (Brassica napus L.), wheat (Triticum aestivum L.), and flax (Linum usitatissimum L.) in 2015; and changes in soil water content during the 2013, 2014, and 2015 growing seasons under canola, flax, wheat, barley (Hordeum vulgare L.), and pea (Pisum sativum L.). Early-season root growth of the canola and flax crops was better on wheat than canola stubble, while for wheat it was similar on the stubbles of both wheat and canola. Soil moisture depletion started relatively earlier under the barley and wheat and later under the flax compared to the canola and pea crops. Flax continued to deplete soil moisture for a longer period than the other crops. With some exceptions, all crops could deplete soil moisture to a similar level (down to about 15% or somewhat lower) by the end of their growing seasons. Generally, almost equal amounts of residual soil moisture remained after the different crops.

Download Full-text