The Effect of Catch Crops on the 15N Nitrogen Percolation and Leaching During the Early Winter Period

1993 ◽  
Vol 29 (1-2) ◽  
pp. 93-97 ◽  
Author(s):  
W. Merbach ◽  
A. Wurbs ◽  
H. Pfeffer ◽  
C. Latus
Keyword(s):  
Winter Period ◽  
Early Winter ◽  
Catch Crops ◽  
15N Nitrogen

The effect of paraquat on oestrogenic isoflavones in Dwalganup subterranean clover

1970 ◽  
Vol 10 (47) ◽  
pp. 729 ◽  
Author(s):  
RC Rossiter ◽  
DW Barrett
Keyword(s):  
Subterranean Clover ◽  
Winter Period ◽  
Early Winter ◽  
Grazed Pastures ◽  
Lethal Doses

Paraquat was sprayed at sub-lethal doses on young clover plants. It decreased leaf isoflavone concentrations by more than 30 per cent. This response was not associated with the defoliating effect of paraquat. The relevance of the finding to grazed pastures is discussed. We argue that our results may be extrapolated to the autumn-early winter period, but not to spring.

scholarly journals Evaluating Different Catch Crop Strategies for Closing the Nitrogen Cycle in Cropping Systems—Field Experiments and Modelling

2021 ◽  
Vol 13 (1) ◽  
pp. 394
Author(s):  
Matthias Böldt ◽  
Friedhelm Taube ◽  
Iris Vogeler ◽  
Thorsten Reinsch ◽  
Christof Kluß ◽  
...  
Keyword(s):  
Field Experiments ◽  
Cropping Systems ◽  
N Uptake ◽  
Red Clover ◽  
Farming Systems ◽  
Grain Legume ◽  
Winter Period ◽  
N Leaching ◽  
Catch Crops ◽  
Cereal Grain

For arable stockless farming systems, the integration of catch crops (CC) during the fallow period might be a key for closing the nitrogen (N) cycle, reducing N leaching and increasing the transfer of N to the subsequent crop. However, despite considerable research efforts, the fate of N in such integrated systems remains unclear. To address this, a two-year field experiment was carried out in northern Germany with different CC, including frost-tolerant and frost-killed CC. The experiment started following a two-year ryegrass/red clover ley, which was subsequently sown with a cereal (CE) or a grain legume (field pea, PE). This provided two contrasting systems with high residual N in autumn. The results showed high N uptake of the CC, ranging from 84 to 136 kg N ha−1 with PE as the pre-crop, and from 33 to 110 kg N ha−1 with CE. All CC reduced N leaching compared with the control, a bare fallow over autumn/winter. Of the various CC, the frost-killed CC showed higher leaching compared with the other CCs, indicating mineralisation of the CC residue in the later autumn/winter period. The process based APSIM (Agricultural Production SIMulator) model was used to simulate N cycling for a cereal grain legume rotation, including a frost-killed and a frost resistant CC. While the model simulated the biomass and the N uptake by the crops, as well as the reduction of N leaching with the use of CC well, it under-estimated N leaching from the frost-killed CC. The study showed that all CC were affective at reducing N leaching, but winter hard catch crops should be preferred, as there is a risk of increased leaching following the mineralisation of residues from frost-killed CC.

scholarly journals Characteristics of Early-Winter Caribou, Rangifer tarandus caribou, Feeding Sites in the Southern Purcell Mountains, British Columbia

2003 ◽  
Vol 117 (3) ◽  
pp. 352 ◽  
Author(s):  
Trevor A. Kinley ◽  
John Bergenske ◽  
Julie-Anne Davies ◽  
David Quinn
Keyword(s):  
British Columbia ◽  
Rangifer Tarandus ◽  
Winter Season ◽  
Subalpine Forest ◽  
Winter Period ◽  
Late Winter ◽  
Abies Lasiocarpa ◽  
Rangifer Tarandus Caribou ◽  
Early Winter ◽  
Winter Habitat

Mountain Caribou are a rare ecotype of Woodland Caribou (Rangifer tarandus caribou) inhabiting the high-snowfall region of southeastern British Columbia, and are defined by their late-winter reliance on arboreal hair lichen of the genus Bryoria. During early winter, there is considerable variation in habitat use among populations. We snow-trailed Caribou in the southern Purcell Mountains during early winter to determine foraging patterns for the Purcell population. When snow was ≤51 cm deep, Caribou fed on Grouseberry (Vaccinium scoparium), the terrestrial lichen Cladonia, and arboreal lichens of the genus Bryoria. When snow was ≥62 cm deep, they ate exclusively arboreal lichens. In both periods, Caribou ate arboreal lichen from essentially every downed tree or branch encountered and fed with a higher intensity at downed trees than standing trees. During the low-snow period, Caribou fed at fewer trees but used those with greater lichen abundance, and fed more intensively at each, compared to the deep-snow period. In comparison to trees occurring on the foraging path but at which Caribou did not feed, those from which arboreal lichen was foraged intensively were of larger diameter, had greater lichen abundance, and were more likely to be Subalpine Fir (Abies lasiocarpa) or Engelmann Spruce (Picea engelmannii) and less likely to be Whitebark Pine (Pinus albicaulis), Lodgepole Pine (P. contorta) or Alpine Larch (Larix lyalli). The shift in diet between the low-snow and deep-snow periods reflected two modes of foraging within the early winter period, distinct from one another and apparently also distinct from the late-winter season. Management for early-winter habitat will require retention of some commercially significant forest across extensive areas, both near the subalpine forest – subalpine parkland ecotone and lower in the subalpine forest.

scholarly journals A preliminary report on the use of FAMACHA© for haemonchosis in goats in the Eastern Cape Province of South Africa during the late autumn / early winter period : short communication

2007 ◽  
Vol 78 (2) ◽  
Author(s):  
C. Sri Jeyakumar
Keyword(s):  
South Africa ◽  
Preliminary Report ◽  
Short Communication ◽  
Winter Period ◽  
Eastern Cape Province ◽  
Early Winter ◽  
Eastern Cape ◽  
Late Autumn ◽  
Resource Poor ◽  
Study Sites

From May to July 2005 a study was conducted on the prevalence and effects of haemonchosis in goats farmed on communal grazing belonging to resource-poor farmers at two study sites, namely Mlungisi (26°53'E, 31°53'S) and Ezibeleni (26°58'E, 31°53'S), situated within the Chris Hani District Municipality in Eastern Cape Province of South Africa. The usefulness of the FAMACHA© system for identifying goats needing treatment was confirmed. It allowed stock owners to identify badly affected goats accurately, as borne out by the agreement between FAMACHA scores and corresponding haematocrits.

scholarly journals Pattern and Characterisation of Human casualties in Sundarban by Tiger attacks, India

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Chandan Surabhi Das
Keyword(s):  
West Bengal ◽  
Winter Period ◽  
Early Winter ◽  
Intensive Study ◽  
Monsoon Period ◽  
Reserve Forest ◽  
Human Animal

A large number of people of the fringe areas of Sundarban enter into the forests every year and encounter with the tigers simply for their livelihood. This study attempts to examine the extent and impact of human-animal conflicts in the Sundarban Reserve Forest (SRF) area in West Bengal, India. An intensive study of the data of the victims (both death and injury) between 1999 and 2014 reveals that, fishermen crab collector, honey collectors and woodcutters are generally victimized by the tiger attack. Pre monsoon period (April to June) and early winter period (Jan to March) are noted for the two-peak periods for casualties. Maximum casualty occurs between 8-10 am, and 2-4 pm. Jhilla (21.1%), Pirkhali (19.72 %), Chandkhali (11.72%), and Arbesi (9.35%) are the four most vulnerable forest blocks accounting more than 60 per cent occurrence of incidences. 67.24 per cent of the tiger attack victims were residents of Gosaba followed by Hingalganja (15%) and Basanti, (9.76%). The vulnerability rating puts the risk of tiger attack to 0.88 for every 10,000 residents of Gosaba block followed by 0.33 at Hingalganj Block and 0.11 at Bansanti Block. The majority of the victims (68%) were found to be males, aged between 30 and 50 years.

scholarly journals Performance of brassica cultivars from New Zealand and United States seed sources in Southeast Ohio, USA

1995 ◽  
pp. 111-113
Author(s):  
Christopher D. Penrose ◽  
Henry M. Bartholomew ◽  
R.Mark Sulc ◽  
Steven D. Schumacher ◽  
Rick Duff
Keyword(s):  
Chinese Cabbage ◽  
Crude Protein ◽  
Dry Matter ◽  
Total Yield ◽  
Winter Period ◽  
Early Winter ◽  
Grazing Season ◽  
Protein Levels ◽  
Seed Sources ◽  
Winter Minimum Temperature

Four turnip cultivars, two Swede, and one each of kale, rutabaga and Chinese-cabbage turnip hybrid were evaluated for their usefulness in extending the grazing season. The three replicates were planted on 28 July 1994 and harvested on 31 October and 3 November 1994. Dry matter yields ranged from 5460 kg/ha for Premier kale to 8877 kg/ha for Rondo turnip. Rondo turnip total yield of DM was significantly higher (P=O.O5) than all other cultivars except Doon Major Swede. Crude protein levels ranged from 8.5% to 24.3% for the tops and 5.9% to 13.4% for the bulbs, with NDF fibre levels of 17.6% to 21.4% for tops and 15.6% to 20.4% for the bulbs. All cultivars survived temperatures of -1O'C with Premier kale being the most winter hardy, surviving the winter minimum temperature of -21°C. Forage brassicas can provide high levels of quality forage for the late autumn and early winter period, significantly extending the grazing season in Ohio and the midwest US. Keywords: brassica, Chinese cabbage-turnip hybrid, grazing season, kale, rutabaga, Swede, turnip

scholarly journals Ozone loss and chlorine activation in the Arctic winters 1991-2003 derived with the tracer-tracer correlations

2004 ◽  
Vol 4 (8) ◽  
pp. 2181-2213 ◽  
Author(s):  
S. Tilmes ◽  
R. Müller ◽  
J.-U. Grooß ◽  
J. M. Russell III
Keyword(s):  
Correlation Method ◽  
Polar Vortex ◽  
The Arctic ◽  
Winter Period ◽  
Time Interval ◽  
Early Winter ◽  
Ozone Loss ◽  
Significant Difference ◽  
Column Ozone ◽  
Polar Ozone

Abstract. Chemical ozone loss in the Arctic stratosphere was investigated for the twelve years between 1991 and 2003 employing the ozone-tracer correlation method. For this method, the change in the relation between ozone and a long-lived tracer is considered for all twelve years over the lifetime of the polar vortex to calculate chemical ozone loss. Both the accumulated local ozone loss in the lower stratosphere and the column ozone loss were derived consistently, mainly on the basis of HALOE satellite observations. HALOE measurements do not cover the polar region homogeneously over the course of the winter. Thus, to derive an early winter reference function for each of the twelve years, all available measurements were additionally used; for two winters climatological considerations were necessary. Moreover, a detailed quantification of uncertainties was performed. This study further demonstrates the interaction between meteorology and ozone loss. The connection between temperature conditions and chlorine activation, and in turn, the connection between chlorine activation and ozone loss, becomes obvious in the HALOE HCl measurements. Additionally, the degree of homogeneity of ozone loss within the vortex was shown to depend on the meteorological conditions. Results derived here are in general agreement with the results obtained by other methods for deducing polar ozone loss. Differences occur mainly owing to different time periods considered in deriving accumulated ozone loss. However, very strong ozone losses as deduced from SAOZ for January in winters 1993-1994 and 1995-1996 cannot be identified using available HALOE observations in the early winter. In general, strong accumulated ozone loss was found to occur in conjunction with a strong cold vortex containing a large volume of possible PSC existence (VPSC), whereas moderate ozone loss was found if the vortex was less strong and moderately warm. Hardly any ozone loss was calculated for very warm winters with small amounts of VPSC during the entire winter. This study supports the linear relationship between VPSC and the accumulated ozone loss reported by Rex et al. (2004) if VPSC was averaged over the entire winter period. Here, further meteorological factors controlling ozone loss were additionally identified if VPSC was averaged over the same time interval as that for which the accumulated ozone loss was deduced. A significant difference in ozone loss (of ≈36DU) was found due to the different duration of solar illumination of the polar vortex of at maximum 4 hours per day in the observed years. Further, the increased burden of aerosols in the atmosphere after the Pinatubo volcanic eruption in 1991 significantly increased the extent of chemical ozone loss.

scholarly journals Climate and weather of the Southern Urals and their influence on agronomy

2020 ◽  
Vol 222 ◽  
pp. 05015
Author(s):  
Yu.M. Nesterenko ◽  
N.V. Solomatin ◽  
A.V. Khalin
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Spring Wheat ◽  
Atmospheric Precipitation ◽  
Southern Urals ◽  
Annual Precipitation ◽  
Winter Period ◽  
Early Winter ◽  
Frozen Ground ◽  
The Southern Urals

Changes in climate, precipitation and air temperature in the Southern Urals over the past 133 years are considered. A decrease in the climatic norm of atmospheric precipitation by 24 mm and an increase in the air temperature in the region by 1.2 º C were revealed. The main decrease in precipitation occurred during the growing season of early crops, and air temperatures in the autumn-winter period, which significantly changed the conditions for agronomy. The increasing aridity of the climate has worsened the conditions for growing spring crops. The applied system of rain-fed agriculture in Orenburg region provides the use of only 30–40% of annual precipitation. Early winter sowing of spring wheat in frozen ground with snow cover up to 10–15 cm is proposed. With them, seed germination, seedlings and tillering of plants are well provided with moisture and have favorable temperature conditions in April-May. Plants with a strong root system can get soil moisture up to 1.5 meters deep and effectively use small precipitation in June and July, which mainly moisturizes the soil to a depth of 5 cm. Early winter sowings of spring wheat are less susceptible to droughts, Favorable soil moisture and air temperature in the spring provide early shoots, plant development and 1.5–2-fold increase in yield. With early winter sowings, the efficiency of using annual precipitation increases to 50–55%.

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