scholarly journals Bromus-Poaresponse to defoliation intensity and frequency under three soil moisture levels

2002 ◽  
Vol 82 (2) ◽  
pp. 365-370 ◽  
Author(s):  
N. T. Donkor ◽  
E. W. Bork ◽  
R. J. Hudson
Keyword(s):  
Soil Moisture ◽  
Crude Protein ◽  
Poa Pratensis ◽  
Field Capacity ◽  
Kentucky Bluegrass ◽  
Bromus Inermis ◽  
Neutral Detergent Fiber ◽  
Moisture Regime ◽  
Boreal Ecosystems ◽  
The Relationship

Smooth brome (Bromus inermis Leyss.) and Kentucky bluegrass (Poa pratensis L.) are important herbage for livestock and wildlife in Aspen-Boreal ecosystems in central Alberta, but there is paucity of information on the relationship between soil moisture and defoliation regimes on herbage production in these ecosystems. In a greenhouse experiment, we evaluated the effect of Bromus-Poa defoliation frequencies (2 or 4 wk) and intensities (2.5, 7.5, or 15 cm above the soil surface) under three soil moisture regimes [field capacity (wet), 50% field capacity (moist), 20% field capacity (dry)] on dry matter (DM) yield. Crude protein (CP) content, crude protein yield (CPY) and neutral detergent fiber (NDF) were also determined for herbage harvested. Total accumulated shoot DM decreased under defoliation compared to the undefoliated control, was higher if plants were clipped every 4 wk, rather than 2 wk, and increased with increasing soil moisture availability. Defoliation regimes decreased root DM Compared to the undefoliated control. Soil moisture regime did not significantly affect below-ground DM production, but root:shoot ratio increased significantly with decreasing moisture supply. The average CP content of grasses ranged from 12 to 23%, but was adequate to meet crude protein requirements of growing, pregnant or lactating grazing cattle (Bos spp.) The CPY decreased with increasing moisture stress, and was greatest when plants were clipped at a 7.5-cm height. Shoot NDF concentration increased with decreasing clipping frequency. These result indicate the need to investigate the relationship between soil moisture and management practices that affect the productivity of tame pastures in Aspen-Boreal ecosystems. Key words: Bromus inermis, Poa pratensis, crude protein, neutral detergent fiber, water

COMPARISON OF FORAGE DIGESTION BY CATTLE AND HORSES

1990 ◽  
Vol 70 (2) ◽  
pp. 601-610 ◽  
Author(s):  
N. F. CYMBALUK
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Poa Pratensis ◽  
Protein Digestibility ◽  
Kentucky Bluegrass ◽  
Neutral Detergent Fiber ◽  
Beef Steers ◽  
Reed Canarygrass ◽  
Alfalfa Hay ◽  
Medicago Sativa L

Two trials compared digestion of Saskatchewan-grown hays by cattle and horses. In the first study, Altai wildrye (Leysum angustus Trin.), smooth bromegrass (Bromus inermus Leyss.), crested wheatgrass (Agropyron cristatum L.), Kentucky bluegrass (Poa pratensis L.), oat hay (Avena sativa L.) and reed canarygrass (Phalaris arundinaceae L.) hays were fed to six beef steers and six crossbred geldings. The second study compared alfalfa hay (Medicago sativa L.) to dehydrated alfalfa pellets. Voluntary dry matter intake (VDMI) of hay by cattle was related to neutral detergent fiber content (R2 = 0.66). No single nutrient reliably predicted VDMI by horses. Cattle and horses had the highest VDMI for bromegrass hay in trial 1. Cattle had similar intakes of dehydrated alfalfa pellets and alfalfa hay, but horses ate 17% more (P < 0.05) hay than pellets. Cattle digested 28–82% more (P < 0.05) fiber from grass hays than horses which may account for their higher dry matter (DM) digestion of these hays. Cattle and horses utilized legume feeds similarly. Energy intakes of all animals exceeded maintenance except for cattle fed reed canarygrass hay. True crude protein digestibility and metabolic fecal protein of forage-fed cattle and horses were estimated at 83.4 and 80.3%, and 2.67 and 2.17 g 100 g−1 DM intake, respectively. Horses had higher true digestibilities of Ca (75%) than P (33%) but cattle digested more P (76%) than Ca (32%). Endogenous fecal Ca excretion for cattle and horses were assessed at 6.5 and 22.1 mg kg−1 body weight (BW), respectively, while endogenous fecal P excretions were 13.3 and 10.2 mg kg−1 BW, respectively. Key words: Horse, cattle, legume, grass, crude protein, fiber

Arsenical Herbicides for Removing Broomsedge from Forage Grasses

Weed Science ◽  
1975 ◽  
Vol 23 (3) ◽  
pp. 222-223
Author(s):  
S. A. Lowance ◽  
E. J. Peters ◽  
R. E. Mattas
Keyword(s):  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Bromus Inermis ◽  
Forage Grasses ◽  
Smooth Bromegrass ◽  
Andropogon Virginicus

MSMA (monosodium methanearsonate) and DSMA (disodium methanearsonate) killed 27 to 90% of the broomsedge (Andropogon virginicusL.) plants when applied at 1.1 to 6.7 kg/ha in July. These rates did not reduce yields of smooth bromegrass (Bromus inermisLeyss.) or affect the density of Kentucky bluegrass (Poa pratensisL.) growing in association with the broomsedge.

Differential Response of Ditchbank Grasses to Herbicides

Weed Science ◽  
1973 ◽  
Vol 21 (5) ◽  
pp. 421-423
Author(s):  
J. M. Hodgson
Keyword(s):  
Trichloroacetic Acid ◽  
Poa Pratensis ◽  
Ammonium Thiocyanate ◽  
Kentucky Bluegrass ◽  
Differential Response ◽  
Bromus Inermis ◽  
Festuca Rubra ◽  
Reed Canarygrass ◽  
Smooth Brome ◽  
Red Fescue

Herbicides were evaluated for selectivity between three tall coarse grasses and three short fine grasses. Reed canarygrass (Phalaris arundinaceaL.), quackgrass [Agropyron repens(L.) Beauv.], and smooth brome (Bromus inermisLeyss) were consistently more susceptible to amitrole-NH4CN (3-amino-s-triazole-ammonium thiocyanate) than three desirable short grasses, Kentucky bluegrass (Poa pratensisL.), creeping red fescue (Festuca rubraL.), and redtop (Agrostis albaL.). Reed canarygrass and redtop were more susceptible to dalapon (2,2-dichloropropionic acid) than creeping red fescue. Amitrole-NH4CN and dalapon combinations were more toxic to reed canarygrass, smooth brome, and redtop than creeping red fescue. Pyriclor (2,3,5-trichloro-4-pyridinol) was quite toxic to all grasses with Kentucky bluegrass showing the most tolerance. When TCA (trichloroacetic acid) was combined with amitrole-NH4CN results were similar to the dalapon combination but overall toxicity was reduced.

Denitrification following herbicide application to a grass sward

1996 ◽  
Vol 76 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Mario Tenuta ◽  
Eric G. Beauchamp
Keyword(s):  
Soil Moisture ◽  
Poa Pratensis ◽  
Fold Increase ◽  
Bromus Inermis ◽  
Herbicide Application ◽  
N Loss ◽  
Treated Soil ◽  
Soil Variables ◽  
Key Words Denitrification ◽  
Grass Sward

The application of the herbicide Roundup (glyphosate), and subsequent death of a predominately bromegrass (Bromus inermis Leyss.) and blue grass (Poa pratensis L.) sward, resulted in a 20- to 30-fold increase in denitrification rate 14 and 49 d after application compared to herbicide-untreated and fallowed soil treatments. The regulation of denitrification by O2, carbon and NO3− availabilities was assessed by measurement of various soil variables. The regulation of denitrification by C and NO3− availabilities was further studied in a laboratory experiment in which denitrification was measured following NO3− and glucose-C addition to soil from the field treatments. Elevated denitrification in the herbicide-treated soil was attributed to increased soil moisture and NO3− contents resulting from the death of vegetation. The death of the grass sward did not increase available C to denitrifiers, whereas the absence of vegetation in the fallowed soil 1 yr following herbicide application reduced available C. This study indicates that herbicide application to a grass sward increases denitrification and hence may contribute to greater nitrous oxide emission and N loss from soil. Key words: Denitrification, herbicide, plants, nitrate, regulation, soil moisture

scholarly journals Hydropedological parameters limiting soil moisture regime floodplain ecosystems of south Moravia

2005 ◽  
Vol 53 (1) ◽  
pp. 71-84
Author(s):  
Ladislav Kubík
Keyword(s):  
Soil Moisture ◽  
Water Retention ◽  
Humus Content ◽  
Field Capacity ◽  
Pedotransfer Functions ◽  
Physical Parameters ◽  
Moisture Regime ◽  
Floodplain Ecosystems ◽  
Soil Moisture Regime ◽  
Wilting Point

Soil moisture regime of floodplain ecosystems in southern Moravia is considerably influenced and greatly changed by human activities. It can be changed negatively by water management engineering or positively by landscape revitalizations. The paper deals with problems of hydropedological characteristics (hydrolimits) limiting soil moisture regime and solves effect of hydrological factors on soil moisture regime in the floodplain ecosystems. Attention is paid especially to water retention curves and to hydrolimits – wilting point and field capacity. They can be acquired either directly by slow laboratory assessment, derivation from the water retention curves or indirectly by calculation using pedotransfer functions (PTF). This indirect assessment uses hydrolimit dependency on better available soil physical parameters namely soil granularity, bulk density and humus content. The aim is to calculate PTF for wilting point and field capacity and to compare them with measured values. The paper documents suitableness utilization of PTF for the region of interest. The results of correlation and regression analysis for soil moisture and groundwater table are furthermore presented.

Water : soil ratio influences aqueous phase chemistry of indigenous copper and zinc in soils

Soil Research ◽  
1997 ◽  
Vol 35 (4) ◽  
pp. 687 ◽  
Author(s):  
Amir Fotovat ◽  
Ravendra Naidu ◽  
Malcolm E. Sumner
Keyword(s):  
Soil Moisture ◽  
Organic Ligand ◽  
Marked Change ◽  
Field Capacity ◽  
Soil Extract ◽  
Alkaline Soils ◽  
Equilibrium Solutions ◽  
Solution Ph ◽  
Minor Elements ◽  
The Relationship

The effect of dilution on the composition of soil solutions of 8 contrasting soils ranging in pH from 5·3 to 8·8 with reference to zinc (Zn) and copper (Cu) was studied. Soil samples were equilibrated with water in various water:soil ratios for 24 h. Equilibrium solutions were extracted and analysed for dissolved organic carbon (DOC), and major and minor elements. The separation of the soil solution at field capacity (FC) was carried out by a drainage method. Although the concentration of ions decreased upon dilution, the total quantity of sodium (Na), potassium (K), Zn, Cu, and DOC extracted per unit of soil weight increased. In contrast, the total quantity of Ca and Mg decreased in most soils. The ratio of Zn and Cu to Ca correlated to dilution level, whereas the ratio of Zn to monovalent cations decreased in low pH soils. The relationship between the quantity of Zn and Cu at different levels of the water : soil ratio in the soils studied showed that the concentration of these trace metals at FC soil moisture can be estimated from the soil extract. Increases in soil moisture content led to a marked change in the ion-pair, free hydrated metal concentrations, and complexation. Log Zn2+ was linearly related to solution pH. Zinc solubility was not consistent with published solubilities of any common minerals. Also, Zn solubility in alkaline soils tended to be higher than reported values in the literature, indicating that soluble metal–organic ligand complexation was underestimated in these soils. The relationship between pH and log Zn2+ was affected by dilution in several ways.

FORAGE YIELD AND QUALITY OF CULTIVATED PERENNIAL GRASSES HARVESTED AT THE EARLY HEADING STAGE

1975 ◽  
Vol 55 (1) ◽  
pp. 271-278 ◽  
Author(s):  
J. N. TINGLE ◽  
C. R. ELLIOTT
Keyword(s):  
Crude Protein ◽  
Dry Matter ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Phleum Pratense ◽  
Forage Yield ◽  
Cultivar Differences ◽  
Grass Species ◽  
Dry Matter Digestibility ◽  
Heading Stage

Fifteen grass species harvested at the early heading stage varied in dry matter yield and contents of crude protein, dry matter digestibility, Ca, K, Mg, Zn, Mn and Cu. Each parameter except Mg and Cu concentrations exhibited differences between cultivars within certain of eight species. Only timothy (Phleum pratense L.) had cultivar differences in dry matter digestibility. Crude protein contents varied between cultivars of meadow fescue (Festuca elatior L.) and Kentucky bluegrass (Poa pratensis L.). Differences between species were greater than between cultivars within species.

Quality and morphological characteristics of alfalfa as affected by soil moisture, pH and phosphorus fertilization

1992 ◽  
Vol 72 (1) ◽  
pp. 147-162 ◽  
Author(s):  
Hélène V. Petit ◽  
A. R. Pesant ◽  
G. M. Barnett ◽  
W. N. Mason ◽  
J. L. Dionne
Keyword(s):  
Soil Moisture ◽  
Soil Ph ◽  
Plant Morphology ◽  
Field Capacity ◽  
Phosphorus Fertilization ◽  
Moisture Regime ◽  
Available Water ◽  
Soil Moisture Regime ◽  
Temperature Regimes ◽  
Moisture Regimes

Alfalfa (Medicago sativa L. ’Saranac’) was grown in a greenhouse on Ste-Rosalie clay and Danby gravelly sandy loam to determine the effects of phosphorus fertilization, air temperature, soil moisture regime and soil pH on chemical composition and plant morphology. The following treatments were applied in factorial combination: three moisture regimes (1, semi-dry, with soil moisture between field capacity or 100% of available water and wilting point or 0% of available water; 2, optimal, between field capacity and 70% of available water; 3, wet, between saturation point and field capacity), three rates of phosphorus in the form of disodium phosphate (0, 12.5 and 25.0 P kg−1 of dry soil) and three soil pH levels (natural, near 5.4, 6.5 and 7.5). Half the alfalfa was grown in a warm greenhouse section with a minimum daytime temperature of 25 °C and 19 °C at night and the other half was grown in a cool section with a daytime minimum of 15 °C and 9 °C at night. Quality of alfalfa was generally improved by water deficit as shown by decreased concentrations of acid detergent fiber (ADF) and acid detergent lignin (ADL) and increased concentrations of crude protein (CP). Cold temperatures decreased ADF content which indicates that quality of alfalfa grown under cold compared to warm temperature regimes is better. Phosphorus fertilization seemed to have more effects on plant morphology and quality under cold than warm temperature regimes. In general, concentrations of CP, ADF and ADL, stem length, leaf area and the number of stems increased in parallel with soil pH. The data indicate that low temperature and low soil moisture regimes were generally associated with higher quality alfalfa than were high temperature and wet soil moisture regimes.Key words: Alfalfa, soil moisture regime, air temperature, phosphorus fertilization, soil pH

scholarly journals Long-term effects of fertilizer on yield and species composition of contrasting pasture swards in the Aspen Parkland of the Northern Great Plains

1997 ◽  
Vol 77 (4) ◽  
pp. 607-614 ◽  
Author(s):  
S. Bittman ◽  
D. H. McCartney ◽  
J. Waddington ◽  
P. R. Horton ◽  
W. F. Nuttall
Keyword(s):  
Species Composition ◽  
Poa Pratensis ◽  
Residual Effect ◽  
Kentucky Bluegrass ◽  
Bromus Inermis ◽  
Festuca Rubra ◽  
Long Term Effects ◽  
Red Fescue ◽  
Aspen Parkland

Little is known about the effects of long-term application of fertilizer on the complex pasture swards of the Aspen Parkland region of western Canada. Experiments were conducted, lasting from 1980 to 1992, on five contrasting swards representative of permanent pastures in northeast Saskatchewan to determine the long-term effects of N, P, K and S fertilizer on herbage yield and species composition. The experimental swards consisted primarily of smooth bromegrass (Bromus inermis Leyss.), Kentucky bluegrass (Poa pratensis L), and creeping red fescue (Festuca rubra L.), in varying amounts. Seven fertilizer treatments were applied at each site from 1980 to 1991 (shown as N-P-K-S in kg ha−1): 0-0-0-0, 45-0-0-0, 45-20-0-0, 90-0-0-0, 90-20-0-0, 90-20-50-20, 180-20-0-0. Another treatment (90-20-0-20) was added in 1984. An area within each plot was protected from grazing with wire exclosures and harvested in July and September. Harvested samples were classified according to coarse-leafed grasses (mostly smooth bromegrass), fine-leafed grasses (mostly Kentucky bluegrass and creeping red fescue), legumes and weeds before drying and weighing. Ground cover composition of all plots was measured by a modified line transect technique in 1980, 1987 and 1992. All swards, regardless of species composition, responded positively to fertilizer. The yield increase obtained from applying 45 or 90 kg N ha−1 (0.8 and 0.7 t ha−1, respectively) was more than doubled by adding 20 kg P ha−1 with the N. Nitrogen applied alone did not affect the proportion of bromegrass but increased the proportion of fine grasses in the herbage; adding N and P increased the proportion of coarse grass and at the expense of fine grasses. With respect to sward composition, N decreased the proportion of bromegrass and increased the proportion of bluegrass and fescue whereas adding N and P had the opposite effect. Application of S increased yield 0.9 to 1.8 t ha−1 and greatly increased the proportion of bromegrass in the sward and the harvested herbage of the three sites with low levels of soil S. The residual effect of the N and P treatments on yield was small but the effect on species composition of the herbage was substantial; S produced a residual effect on yield in 1992 and a large residual effect on species composition. The results indicate the need for balanced nutrient application to enhance yield and maintain or improve sward species composition of pastures in the Aspen Parkland. Fertilizer can be used to improve yield on a wide range of sward types. Key words: Bromegrass, Bromus inermis, bluegrass, Poa pratensis, fescue, Festuca rubra, legume, N, P, K, S, grazing, species diversity

A carbon-based method for estimating the wetness of forest surface soil horizons

2007 ◽  
Vol 37 (4) ◽  
pp. 846-852 ◽  
Author(s):  
Donald S. Ross
Keyword(s):  
Soil Moisture ◽  
Water Content ◽  
Field Capacity ◽  
Least Squares Regression ◽  
Soil C ◽  
Soil Calcium ◽  
The Relationship ◽  
Water Holding ◽  
Soil Moisture Retention ◽  
Gravimetric Water Content

The degree of wetness in forest surface soils has an effect on chemical and biological processes but is not easily measured. The high spatial variability in carbon (C) concentration creates high variability in water-holding capacity, and gravimetric water content is not informative. Local hydrology can create patchiness in soil moisture, with saturated soils often found near well-drained ones. When sampling to measure such factors as nitrification potential, it would be advantageous to have a simple metric that reflects the relative wetness of the soil. The relationship between C concentration (range 51.5–520.8 g·kg–1) and gravimetric water content was found to be linear for a set of 113 H- and A-horizon samples assumed to be at field capacity. The wetness ratio is defined as the actual water content of a sample divided by the water content predicted by the least squares regression equation based on C concentration (soil water content (kg·kg–1) = 0.080 + 0.0057 soil C concentration (g·kg–1)). Soil moisture retention curves were developed for a small number of samples in the range of 0 to about –10 kPa and showed that the equation predicted that water would be held at relatively high potential. In samples taken from 10 watersheds in the northeastern USA, wetness ratios between 1.25 and 3.1 were associated with soils identified in the field as ranging from wet to boglike. A median ratio of 0.49 was found in a watershed sampled after an extended dry period. At the Sleepers River Research Watershed, high wetness ratios were associated with a high soil calcium concentration, presumably from enriched groundwater. The ratio should be a useful measurement in watershed studies.

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