The effect of early spring grazing and dairy cow grazing intensity on particulate phosphorus losses in surface run-off

2015 ◽  
Vol 71 (1) ◽  
pp. 172-176
Author(s):  
D. A. McConnell ◽  
D. G. Doody ◽  
C. T. Elliott ◽  
D.I. Matthews ◽  
C. P. Ferris
Keyword(s):  
Dairy Cow ◽  
Grazing Intensity ◽  
Early Spring ◽  
Particulate Phosphorus ◽  
Run Off ◽  
Phosphorus Losses

scholarly journals Seasonal shifts in export of DOC and nutrients from burned and unburned peatland-rich catchments, Northwest Territories, Canada

2018 ◽  
Vol 22 (8) ◽  
pp. 4455-4472 ◽  
Author(s):  
Katheryn Burd ◽  
Suzanne E. Tank ◽  
Nicole Dion ◽  
William L. Quinton ◽  
Christopher Spence ◽  
...  
Keyword(s):  
Climate Change ◽  
Mineral Soil ◽  
Fire Regimes ◽  
Forest Litter ◽  
Early Spring ◽  
Permafrost Region ◽  
Spring Period ◽  
Discontinuous Permafrost ◽  
Run Off ◽  
Spring Freshet

Abstract. Boreal peatlands are major catchment sources of dissolved organic carbon (DOC) and nutrients and thus strongly regulate the landscape carbon balance, aquatic food webs, and downstream water quality. Climate change is likely to influence catchment solute yield directly through climatic controls on run-off generation, but also indirectly through altered disturbance regimes. In this study we monitored water chemistry from early spring until fall at the outlets of a 321 km2 catchment that burned 3 years prior to the study and a 134 km2 undisturbed catchment. Both catchments were located in the discontinuous permafrost zone of boreal western Canada and had  ∼  60 % peatland cover. The two catchments had strong similarities in the timing of DOC and nutrient yields, but a few differences were consistent with anticipated effects of wildfire based on peatland porewater analysis. The 4-week spring period, particularly the rising limb of the spring freshet, was crucial for accurate characterization of the seasonal solute yield from both catchments. The spring period was responsible for  ∼  65 % of the seasonal DOC and nitrogen and for  ∼  85 % of the phosphorous yield. The rising limb of the spring freshet was associated with high phosphorous concentrations and DOC of distinctly high aromaticity and molecular weight. Shifts in stream DOC concentrations and aromaticity outside the early spring period were consistent with shifts in relative streamflow contribution from precipitation-like water in the spring to mineral soil groundwater in the summer, with consistent relative contributions from organic soil porewater. Radiocarbon content (14C) of DOC at the outlets was modern throughout May to September (fraction modern carbon, fM: 0.99–1.05) but likely reflected a mix of aged DOC, e.g. porewater DOC from permafrost (fM: 0.65–0.85) and non-permafrost peatlands (fM: 0.95–1.00), with modern bomb-influenced DOC, e.g. DOC leached from forest litter (fM: 1.05–1.10). The burned catchment had significantly increased total phosphorous (TP) yield and also had greater DOC yield during summer which was characterized by a greater contribution from aged DOC. Overall, however, our results suggest that DOC composition and yield from peatland-rich catchments in the discontinuous permafrost region likely is more sensitive to climate change through impacts on run-off generation rather than through altered fire regimes.

The effect of extending the grazing season in early spring on dairy cow performance

1998 ◽  
Vol 1998 ◽  
pp. 50-50 ◽  
Author(s):  
H.J. Sayers ◽  
C.S. Mayne
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Early Spring ◽  
Feeding Period ◽  
Animal Performance ◽  
Grazing Season ◽  
Cow Performance

Previous studies (Mayne and Laidlaw 1995) have shown that early turnout of dairy cows to spring pasture for a few hours per day (extended grazing) reduces silage intake and increases animal performance relative to that of animals retained indoors. The objective of the present study was to assess the effects of grazing severity and/or degree of silage restriction during the indoor feeding period on the response to extended grazing.

Modelling the impacts of management practices on agricultural phosphorus losses to surface waters of Finland

1999 ◽  
Vol 39 (12) ◽  
pp. 265-272 ◽  
Author(s):  
S. Rekolainen ◽  
J. Grönroos ◽  
I. Bärlund ◽  
A. Nikander ◽  
Y. Laine
Keyword(s):  
Management Practices ◽  
Soil Tillage ◽  
Particulate Phosphorus ◽  
The European Union ◽  
Environmental Support ◽  
Dissolved Phosphorus ◽  
Tillage Practices ◽  
Green Cover ◽  
Cultivation Practices ◽  
Phosphorus Losses

This paper presents the changes in cultivation practices in Finnish agriculture resulting from the Agri-Environmental Support Scheme of the Common Agricultural Policy of the European Union. Detailed data were collected by interviewing farmers in four different areas of the country. The potential impacts of changes in cultivation practices on phosphorus losses were assessed using a mathematical simulation model. The variables monitored were: fertilization, winter green cover and soil tillage methods in autumn. The use of fertilizers has decreased to meet the requirements of the support programme. Winter green cover has increased in areas to a minimum level of 30% of the cultivated area. However, the potential impacts on nutrient losses were small. There are two reasons for this: the increase in reduced tillage practices is likely to increase the loss of dissolved phosphorus in southern Finland, and the reduction of set-aside has led to slight increases in particulate phosphorus losses. However, the reduction in grassland fertilization rapidly decreased loss of dissolved phosphorus in northern Finland.

Effect of grazing intensity and number of grazings on herbage production and seed yields of Trifolium subterraneum, Medicago murex, and Ornithopus compressus

1994 ◽  
Vol 34 (2) ◽  
pp. 181 ◽  
Author(s):  
DJ Conlan ◽  
BS Dear ◽  
NE Coombes
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Grazing Intensity ◽  
Trifolium Subterraneum ◽  
Grazing Pressure ◽  
Early Spring ◽  
Pasture Legumes ◽  
Heavy Grazing ◽  
Ornithopus Compressus ◽  
The Impact

The impact of grazing intensity and number of grazings was assessed on the growth and seed production of 5 annual pasture legumes [Trifoliunz subterraneum var. subterraneum cv. Karridale, var. brachycalycinum cv. Clare, var. yanninicum cv. Trikkala; Medicago murex (murex medic) cv. Zodiac; Ornithopus compressus L. (yellow serradella) cv. Avila]. There were 7 grazing treatments: an ungrazed control; and 2 grazing intensities (light and heavy), each for 3 periods of grazing (winter, winter-early spring, winter-late spring). Tethered sheep in small experimental plots were used to provide controlled herbage removal across all cultivars through winter and winter-spring grazing. This grazing system resulted in significantly different levels of herbage being present in the light and heavy grazing treatments following each grazing period. Grazing had variable effects on seed production: <35% increase for Trikkala, and no significant effect for Karridale. Both cultivars continued growth and seed production late in the season after grazing pressure was removed on 8 November. Seed yield of Clare was reduced by 46-49% by heavy grazing treatments. Seed yield of murex medic was not significantly affected by grazing, while that of serradella was reduced by 30-55% by grazing late in the season. The seed yield responses show that cultivar and species responses to grazing may be highly variable. Under favourable spring conditions, Trikkala, Karridale, and murex medic can be grazed heavily until late in the season without adversely affecting seed yield, whilst Clare and Avila cannot.

Recommendations for control of cone and seed insect pests of black spruce, Picea mariana (Mill.) B.S.P., with insecticides

1999 ◽  
Vol 75 (4) ◽  
pp. 685-691 ◽  
Author(s):  
Kevin W. Wanner ◽  
Barry C. Kostyk ◽  
Blair V. Helson
Keyword(s):  
Insect Pests ◽  
Black Spruce ◽  
Spruce Budworm ◽  
Female Flower ◽  
Early Spring ◽  
Flower Bud ◽  
Run Off ◽  
Flower Abortion ◽  
Label Dose ◽  
Cone And Seed Insects

Foliar sprays of dimethoate (1.25 g AI per tree) and permethrin (0.028 g AI per tree), applied to run-off one week prior to female flower bud flush, significantly reduced flower abortion, cone grazing, and shoot grazing caused by spruce budworm, Choristoneura fumiferna (Clem.), larvae as well as damage by the spruce cone maggot, Strobilomyia appalachensis (Michelsen). Treatment with Bacillus thuringiensis var. kurstaki (B.t.) (0.012 B.U.I, per tree) resulted in moderate protection from grazing damage to female flowers and cones as compared to treatment with dimethoate and permethrin. Systemic applications of acephate also reduced damage by spruce budworm larvae and the spruce cone maggot: fall and early spring applications were equal in efficacy, and the label rate (0.875 g acephate/3.2 cm dbh) provided similar protection to the half-label dose. Key words: Insecticides, black spruce, efficacy, recommendations, cone and seed insects

Simultaneous effect of habitat remnancy, exotic species and anthropogenic disturbance on orchid diversity and abundance

2021 ◽  
Author(s):  
Irene Martín-Forés ◽  
Samantha L. Bywaters ◽  
Ben Sparrow ◽  
Greg Guerin
Keyword(s):  
Habitat Fragmentation ◽  
Species Composition ◽  
Exotic Species ◽  
Anthropogenic Disturbance ◽  
Grazing Intensity ◽  
Grazing Pressure ◽  
Ecological Condition ◽  
Early Spring ◽  
Floral Resources ◽  
Surrounding Areas

Orchids are potentially useful as ecological indicators because of their sensitivity to habitat fragmentation and anthropogenic disturbance. While many studies explore the effect of single factors on orchid diversity, few investigate how the extent, configuration and condition of surrounding habitat affect whole orchid communities. Here, we unravel the effect of biological invasions, anthropogenic disturbance (i.e. grazing pressure, ecological condition), habitat fragmentation and climate on an Australian orchid community. We sampled 39 plots across nine sites in the Mount Lofty Ranges, Australia. We recorded the number of orchid species and number of individuals per species in mid-winter, early-spring and late-spring to account for the effect of season on species visibility, with 115 surveys in total. We ranked grazing intensity and ecological condition, and estimated cover of exotic species. We analysed the response of richness and diversity through generalised linear mixed models, and differences in species composition through non-metric multidimensional scaling. We also explored fruiting success in two species associated with floral resources in the surrounding habitat. Habitat configuration in the surrounding landscape had different effects at increasing radii. Patch-level orchid diversity was positively correlated with habitat edges in the immediate area, and with habitat cohesion at medium scales, whereas diversity was negatively correlated with increasing habitat area across larger surrounding areas. Orchids co-existed with exotic species but were negatively affected once exotic cover exceeded 20%. Species composition was correlated with both exotic cover and level of disturbance. Fruiting success was unrelated to floral resources of the surrounding vegetation, although associated with certain bee-attracting species. Our findings reveal a complex relationship between orchid communities and their surrounding environments suggesting that while orchids benefit from a somewhat disturbed landscape, they fail to thrive once exotic cover exceeds 20%. These idiosyncratic responses suggest orchid diversity may be unreliable as early-warning indicators of habitat disturbance.

The effect of extending the grazing season in early spring on dairy cow performance

1998 ◽  
Vol 1998 ◽  
pp. 50-50
Author(s):  
H.J. Sayers ◽  
C.S. Mayne
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Early Spring ◽  
Feeding Period ◽  
Animal Performance ◽  
Grazing Season ◽  
Cow Performance

Previous studies (Mayne and Laidlaw 1995) have shown that early turnout of dairy cows to spring pasture for a few hours per day (extended grazing) reduces silage intake and increases animal performance relative to that of animals retained indoors. The objective of the present study was to assess the effects of grazing severity and/or degree of silage restriction during the indoor feeding period on the response to extended grazing.

Intensive rotational grazing for dairy cattle feeding

1995 ◽  
Vol 10 (4) ◽  
pp. 147-151 ◽  
Author(s):  
J.W. Rust ◽  
C.C. Sheaffer ◽  
V.R. Eidman ◽  
R.D. Moon ◽  
R.D. Mathison
Keyword(s):  
Body Weight ◽  
Dairy Cattle ◽  
Milk Production ◽  
Dairy Cow ◽  
Perennial Grass ◽  
Early Spring ◽  
Weight Changes ◽  
Rotational Grazing ◽  
Body Weight Changes ◽  
Cattle Feeding

AbstractA 2-year study compared milk production and profitability for confinement feeding versus rotational grazing. Guernsey and Guernsey x Holstein cows grazed perennial grass pastures from mid-May to October or were fed in confinement. Averaged over both years, confined cows produced 7% more milk; their milk was similar in fat concentration to that of grazing cows. Body weight changes and health of the two groups were similar. Net return per cow averaged $64 higher for rotational grazing than for confinement because of lower costs for feeding, facilities, equipment, and labor. Intensive rotational grazing of pastures is a competitive alternative for dairy cow feeding. However, farmers in the northern U.S. will still require stored feeds from late fall through early spring.

A note on the feeding value of Persian clover grazed by dairy cows in mid lactation

1992 ◽  
Vol 54 (2) ◽  
pp. 305-308
Author(s):  
C. R. Stockdale
Keyword(s):  
Dry Matter ◽  
Grazing Intensity ◽  
Early Spring ◽  
Marginal Return ◽  
Feeding Value ◽  
Persian Clover ◽  
Trifolium Resupinatum ◽  
Friesian Cows

An experiment was carried out for 4 weeks in early spring with 20 Friesian cows in their 6th month of lactation. Treatments were associated with grazing intensity of Persian clover (Trifolium resupinatum) such that daily pasture intakes ranged from 10·0 to 19·5 kg dry matter (DM) per cow. The marginal return to extra feeding obtained over the whole range of grazing treatments averaged only 0·4 kg milk for each additional kg DM of Persian clover eaten. This was very low considering the quality of the diet on offer (0·73 digestibility in vitro). It is suggested that a leaf fungal disease may have been implicated; this is discussed.

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