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 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

scholarly journals Impacts of soil moisture level and organic matter content on growth of two Juncus species and Poa pratensis grown under acid soil conditions

Weed Research ◽  
2019 ◽  
Vol 59 (6) ◽  
pp. 490-500
Author(s):  
W Kaczmarek‐Derda ◽  
M Helgheim ◽  
J Netland ◽  
H Riley ◽  
K Wærnhus ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Poa Pratensis ◽  
Acid Soil ◽  
Organic Matter Content ◽  
Matter Content ◽  
Moisture Level ◽  
Soil Conditions ◽  
Soil Moisture Level

Effect of Bromus inermis Leyss Planting on Dynamic Changes of Soil Moisture Contents on the Bare Slope

2013 ◽  
Vol 807-809 ◽  
pp. 1648-1652
Author(s):  
Tie Jun Sun ◽  
Baderihu Tajilake
Keyword(s):  
Soil Moisture ◽  
Moisture Content ◽  
Soil Moisture Content ◽  
Regulatory Mechanism ◽  
Dynamic Balance ◽  
Bromus Inermis ◽  
Dynamic Changes ◽  
Moisture Contents ◽  
Biological Characters ◽  
Underground Biomass

Experiment was executed to plant eco-grass of Bromus inermis Leyss on 15°bare slopes, and study effect of biological characters on dynamics of soil moisture contents. The results indicated that vegetation restored quickly on the bare slope after the eco-grass planted. There were 2473.4 kg/hm2 of overground biomass and 1744.1kg/hm2 of underground biomass, and 70% of underground biomass was in 0-10cm layer of soil. Meanwhile, there was a regulatory mechanism of soil moisture content for Bromus inermis Leyss. When rainfall was enough, soil moisture content in 0-80 cm layer could reach to the most of 26.83% quickly this year. Next it could decline near to the first value of 19.81% after rainfall stopped, and keep a dynamic balance between 19.48% and 19.96%. Moreover, the regulatory mechanism realized though underground biomass, and was clearer with underground biomass increasing, especially in the 0-40cm layer of soil.

Factors Affecting Thiocarbamate Injury to Corn I. Temperature and Soil Moisture

Weed Science ◽  
1976 ◽  
Vol 24 (3) ◽  
pp. 319-321 ◽  
Author(s):  
G. W. Burt ◽  
A. O. Akinsorotan
Keyword(s):  
Zea Mays ◽  
Soil Moisture ◽  
Critical Time ◽  
Factors Affecting ◽  
Treated Soil ◽  
Growth Chambers

Corn (Zea maysL.) was grown in EPTC-(S-ethyl dipropylthiocarbamate) and butylate-(S-ethyl diisobutylthiocarbamate) treated soil at 33 and 15% moisture in growth chambers at 30 and 20 C. EPTC (6 and 18 ppm) and butylate (19 and 50 ppm) reduced corn growth more at 30 than at 20 C. The days before emergence of the corn coleoptile were the most critical time for thiocarbamate injury. When plants were grown at 30 C before emergence more injury occurred at 33% soil moisture than at 15% except with butylate at 19 ppm. At 20 C, however, plants grew as tall or taller at 33% soil moisture than at 15% except for butylate at 19 ppm. Addition of R-25788 (N,N-diallyl-2,2-dichloroacetamide) to EPTC and butylate increased by about 10 times the amount of herbicide required to injure corn. With R-25788 the toxicity of these two herbicides was not influenced greatly by either temperature or soil moisture.

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.

Release of Ammonia and Greenhouse Gases along Moisture Gradient from Manure and Urea Applied Fargo Silty Clay Soil

2018 ◽  
Vol 34 (6) ◽  
pp. 939-952
Author(s):  
Suresh Niraula ◽  
Shafiqur Rahman ◽  
Amitava Chatterjee
Keyword(s):  
Carbon Dioxide ◽  
Soil Moisture ◽  
Greenhouse Gas ◽  
Clay Soil ◽  
Carbon Dioxide Emission ◽  
Water Holding Capacity ◽  
Silty Clay ◽  
Treated Soil ◽  
Silty Clay Soil ◽  
Water Holding

Abstract. Greenhouse gas (GHG) [nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4)] emission and ammonia (NH3) volatilization from organic and commercial fertilizers are likely related to soil moisture levels. Effect of soil moisture [(30%, 60%, and 90% water-holding capacity (WHC)] on emissions from urea and manure treated (215 kg ha-1) Fargo-Ryan silty clay soil was studied under laboratory conditions. Soils (250 g) amended with solid beef manure (SM), straw-bedded solid beef manure (BM), urea (UR), and control (CT) were incubated for 28 days at 22±1°C, to determine GHGs (N2O, CO2, and CH4) emission and NH3 volatilization loss. The cumulative emission of N2O-N, CO2-C, and CH4-C ranged from 27 to 4402 µg N2O-N kg-1, 272 to 2030 mg CO2-C kg-1, and 10.1 to 1389 µg CH4-C kg-1 soil, respectively. The daily fluxes and cumulative emissions of N2O and CO2 generally followed the decreasing order of 30% < 90% < 60% of WHC. At 60% WHC, 1.01% of the total applied N was lost as N2O from urea treated soil. Carbon dioxide emission from manure treated soil (SM and BM) was up to two times the emission from UR treated soils. The Fargo clay soils showed higher CH4 emission at 90% WHC level. The cumulative NH3 volatilization loss from soil ranged from 29.4 to 1250.5 µg NH3-N kg-1, with the highest loss from UR amended soils at 30% WHC. These results suggest that gaseous emissions from manure and urea application under laboratory study are influenced by moisture levels of Fargo-Ryan silty clay soil. Keywords: Beef manure, Greenhouse gas, Soil water, Urea, Water holding capacity.

Factors Affecting Toxicity and Translocation of Glyphosate in Cotton(Gossypium hirsutum)

Weed Science ◽  
1978 ◽  
Vol 26 (5) ◽  
pp. 509-513 ◽  
Author(s):  
G. D. Wills
Keyword(s):  
Relative Humidity ◽  
Gossypium Hirsutum ◽  
Constant Temperature ◽  
Environmental Conditions ◽  
Plant Tissue ◽  
Fold Increase ◽  
Herbicide Application ◽  
Factors Affecting ◽  
Treated Area ◽  
Lower Stem

Toxicity of nonradiolabeled and translocation of14C-labeled glyphosate [N-(phosphonomethyl)glycine] in cotton(Gossypium hirsutumL.) were evaluated under different environmental conditions as affected by surfactant and by the maturity of the plant tissue at the place of herbicide application. Toxicity was affected primarily by temperature with 21 to 40% greater cotton injury at 25 C than at 35 C. The addition of surfactant often increased toxicity under environmental conditions where toxicity was initially low. Absorption and translocation of14C was affected primarily by relative humidity (RH). At constant temperature and rate of surfactant, an increase in RH from 40 to 100% resulted in a 3- to 6-fold increase in translocation of14C. Autoradiograms indicated that the movement of the14C-label was primarily into leaves above the treated area. Translocation of14C was significantly greater following application to the mature lower stem than to the mature lower leaves or to immature upper stem or leaves of cotton.

scholarly journals Higher Long-Term Soil Moisture Increases Organic Carbon Accrual Through Microbial Conversion of Organic Inputs

2021 ◽  
Author(s):  
Itamar Shabtai ◽  
Srabani Das ◽  
Thiago Inagaki ◽  
Behrooz Azimzadeh ◽  
Carmen Martínez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Chemical Composition ◽  
Organic Carbon ◽  
Fold Increase ◽  
Sodium Dithionite ◽  
Sodium Pyrophosphate ◽  
Microbial Conversion ◽  
High Moisture

High long-term soil moisture may either stimulate or inhibit soil organic carbon (SOC) losses through changes to mineral and chemical composition, and resultant organo-mineral interactions. Yet, the trade-off between mineralization and accrual of SOC under long-term variation in unsaturated soil moisture remains an uncertainty. In this study, we tested the underexplored relationships between long-term soil moisture and organo-mineral chemical composition, and its implications for SOC persistence. The results provide new insights into SOC accrual mechanisms under different long-term moisture levels commonly observed in well-drained soils. Differences in long-term mean volumetric water content ranging from 0.4 - 0.63 (v/v) on fallow plots in an experimental field in New York, USA, were positively correlated with SOC contents (R2 = 0.228; P = 0.019, n = 20), mineral-associated organic matter (MAOM) (R2 = 0.442; P = 0.001; n = 20) and occluded particulate organic matter (oPOM) contents (R2 = 0.178; P = 0.033; n = 20). Higher long-term soil moisture decreased the relative content of sodium pyrophosphate extractable Fe (R2 = 0.33; P < 0.005; n = 20), increased that of sodium dithionite extractable Fe (R2 = 0.443; P < 0.001; n = 20), and increased the overall importance of non-crystalline Al pools (extracted with sodium pyrophosphate and hydroxylamine extractable) for SOC retention. Higher long-term soil moisture supported up to a four-fold increase in microbial biomass (per unit SOC), and lower C:N ratios in MAOM fractions of high-moisture soils (from C:N 9.5 to 9, R2 = 0.267, P = 0.011, n =20). This was reflected by a 15% and 10% greater proportion of oxidized carboxylic-C to aromatic-C and O-alkyl C, respectively, as measured with 13C-NMR, and a more pronounced FTIR signature of N-containing proteinaceous compounds in high-moisture MAOM fractions, reflective of microbial metabolites. SOC accrual increased with increasing soil moisture (P = 0.019), exchangeable Ca2+ (P = 0.013), and pyrophosphate-extractable Al content (P = 0.0001) and Al/Fe ratio (P = 0.017). Taken together, our results show that high long-term soil moisture resulted in SOC accrual by enhancing microbial conversion of plant inputs to metabolites that interact with reactive minerals.

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