Simulation of odour dispersion downwind from natural windbreaks using the computational fluid dynamics standard k-ε modelA paper submitted to the Journal of Environmental Engineering and Science.

2009 ◽  
Vol 36 (5) ◽  
pp. 895-910 ◽  
Author(s):  
Xing Jun Lin ◽  
Suzelle Barrington ◽  
Guangcai Gong ◽  
Denis Choinière
Keyword(s):  
Wind Velocity ◽  
Mixing Layer ◽  
Field Trials ◽  
Climatic Conditions ◽  
Pressure Jump ◽  
Air Turbulence ◽  
Odour Plume ◽  
Fluent Software ◽  
Odour Concentration ◽  
Odour Dispersion

If natural windbreaks create air turbulence and can help disperse odours from livestock operations, their dispersion effect has not been extensively researched. This paper introduces a model simulating odour dispersion downwind from natural windbreaks. The standard k-ε model of the FLUENT software was used to incorporate the effect of climatic conditions and windbreak structure. The model was calibrated for wind velocity recovery, odour concentration (OC) from field observations and inertial resistance. Once calibrated, the model accurately reproduced the odour plume developing downwind from the windbreak. The correlation between OC for 11 field trials and that simulated were statistically significant (P < 0.01), indicating that the model was accurate. The model demonstrated that a windbreak did alter the magnitude and direction of the wind velocity, thus creating a pressure jump across its width. This pressure jump produces a strong downwind turbulence forming a mixing layer capable of enhancing odour dispersion.

Field performance and early test results of offspring from two Norway spruce seed orchards containing clones transferred to warmer climates

2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen
Keyword(s):  
Norway Spruce ◽  
Field Performance ◽  
Seed Orchard ◽  
Field Trials ◽  
Climatic Conditions ◽  
Test Results ◽  
Seed Orchards ◽  
Low Altitude ◽  
Natural Stands ◽  
Seed Crops

We present results from early tests and field trials of offspring from two Norway spruce ( Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.

Conservation agriculture for climate smart agriculture in smallholder farming systems in Kenya.

2022 ◽  
pp. 431-442
Author(s):  
Alfred Micheni ◽  
Patrick Gicheru ◽  
Onesmus Kitonyo
Keyword(s):  
Crop Yields ◽  
Farming Systems ◽  
Conservation Agriculture ◽  
Field Trials ◽  
Climatic Conditions ◽  
Smallholder Farming ◽  
Yield Increase ◽  
Adequate Food ◽  
Labour Requirement ◽  
Smart Agriculture

Abstract Climate change is any significant change in climatic conditions. Such changes may negatively affect productivity of the rain-fed agriculture practised by over 75% of the smallholder Kenyan farmers. The effect leads to failure to sustainably provide adequate food and revenue to famers. It is on this basis that an almost 8-year field study was conducted to evaluate and scale climate resilient agricultural technological options associated with Conservation Agriculture (CA) systems and practices (no-till; maintenance of permanent soil cover; and crop diversification - rotations and associations), complemented with good agricultural strategies. The activities involved were targeted to sustainably increase productivity of maize-legumes farming systems while reducing environmental risks. The results showed improved soil properties (physical, chemical and health) and consequently increased crop yields and human nutrition by over 30%. Such benefits were attributed to cost savings arising from NT and reduced labour requirement for weed control. This was further based on enhanced crop soil moisture and nutrients availability and use efficiency leading to over 25% yield increase advantage. Apart from the field trials, the study used the Agricultural Production Simulator (APSIM) computer model to simulate CA scenario with the aim of providing potential quick answers to adopting CA practices for farm system productivity. The results were inclusively shared, leading to over 21% increase in the number of farmers adopting the CA practices within and beyond the project sites. The study's overall recommendation affirmed the need to integrate the CA practices into Kenyan farming systems for sustainable agricultural livelihoods and economic opportunities.

Comparison of Application Methods and Tillage Practices on Volatilization of Clomazone

1988 ◽  
Vol 2 (3) ◽  
pp. 323-326 ◽  
Author(s):  
Kurt D. Thelen ◽  
James J. Kells ◽  
Donald Penner
Keyword(s):  
Field Trials ◽  
Conventional Tillage ◽  
Climatic Conditions ◽  
No Tillage ◽  
Minimum Tillage ◽  
Tillage Practices ◽  
Surface Application ◽  
Application Methods

Field trials were conducted in 1985 and 1986 to determine the effect of incorporation on volatilization of clomazone from soil. Volatilization was detected up to 2 weeks after surface-applied or soil-incorporated treatments of clomazone at 1.1 kg ai/ha. The amount of volatilization detected was greatest following rainfall and varied between years. More clomazone volatilized after surface application than after incorporation, regardless of the climatic conditions present. Clomazone volatilization detected was in the order of no-tillage > minimum tillage > conventional tillage.

scholarly journals Semi-Minimal Pruned Hedge: A Potential Climate Change Adaptation Strategy in Viticulture

Agronomy ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 173 ◽  
Author(s):  
Daniel Molitor ◽  
Mareike Schultz ◽  
Robert Mannes ◽  
Marine Pallez-Barthel ◽  
Lucien Hoffmann ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Change Adaptation ◽  
Field Trials ◽  
Adaptation Strategy ◽  
Climatic Conditions ◽  
Training System ◽  
Soluble Solids ◽  
Maturity Period ◽  
Mechanical Thinning ◽  
Bunch Rot

The low-input viticultural training system ‘Semi-minimal pruned hedge’ (SMPH) is progressively being more widely applied in the Central European grapegrowing regions. The present study examined the influence of (i) the training system (SMPH versus the vertical shoot position (VSP) system), (ii) the timing of shoot topping in SMPH, and (iii) the effects of mechanical thinning in SMPH on the bunch rot epidemic, grape maturity, and yield. Six-year field trials on Pinot blanc in Luxembourg demonstrated that yield levels in non-thinned SMPH treatments were 74% higher, and total soluble solids (TSS) at harvest 2.2 brix lower than in VSP. Non-thinned SMPH delayed the bunch rot epidemic and the maturity progress by 18 and 11 days compared to VSP, respectively. Different shoot-topping timings in SMPH did not affect the tested parameters. Mechanical thinning regimes reduced the yield by 28% (moderate thinning) and 53% (severe thinning) compared to non-thinned SMPH and increased TSS by 0.8 and 1.3 brix, respectively. Delayed bunch rot epidemic and maturity progress give rise to the opportunity for a longer maturity period in cooler conditions, making this system of particular interest in future, warmer climatic conditions. Providing that yield levels are managed properly, SMPH might represent an interesting climate change adaptation strategy.

Tolerance of identity preserved soybean cultivars to preemergence herbicides

2015 ◽  
Vol 95 (4) ◽  
pp. 719-726 ◽  
Author(s):  
Kimberly D. Belfry ◽  
Nader Soltani ◽  
Lynette R. Brown ◽  
Peter H. Sikkema
Keyword(s):  
Yield Loss ◽  
Field Trials ◽  
Climatic Conditions ◽  
Recommended Dose ◽  
Yield Reduction ◽  
Soybean Yield ◽  
Soybean Cultivars ◽  
Chlorimuron Ethyl ◽  
Preemergence Herbicides

Belfry, K. D., Soltani, N., Brown, L. R. and Sikkema, P. H. 2015. Tolerance of identity preserved soybean cultivars to preemergence herbicides. Can. J. Plant Sci. 95: 719–726. Six field trials were conducted over a 3-yr period (2011 to 2013) near Exeter and Ridgetown, Ontario, Canada, to assess the tolerance of seven identity-preserved (IP) soybean cultivars to preemergence (PRE) herbicides applied at 2×the recommended dose. All cultivars demonstrated excellent tolerance to dimethenamid-P, pyroxasulfone, S-metolachlor, chlorimuron-ethyl, clomazone, cloransulam-methyl, flumetsulam and imazethapyr, showing 5% or less injury. At Exeter, linuron caused as much as 13 and 18% injury at 2 and 4 wk after soybean emergence, while injury due to metribuzin was as high as 22 and 47% for the same dates, respectively. At Exeter, linuron, metribuzin and S-metolachlor plus metribuzin reduced soybean height up to 17, 41 and 24%, respectively; soybean height was generally not affected at the Ridgetown sites. At Exeter, metribuzin reduced soybean yield up to 38% for cultivars S03W4, Madison and OAC Lakeview, while S23T5 was not significantly reduced. On the contrary, metribuzin yield loss at Ridgetown was nonsignificant. Results from this study suggest that PRE application of metribuzin at 2× field dose has potential to cause unacceptable injury and yield reduction in IP soybeans under some soil and climatic conditions and may vary according to cultivar.

scholarly journals Potential for foliar phosphorus fertilisation of dryland cereal crops: a review

2010 ◽  
Vol 61 (8) ◽  
pp. 659 ◽  
Author(s):  
S. R. Noack ◽  
T. M. McBeath ◽  
M. J. McLaughlin
Keyword(s):  
Cropping Systems ◽  
Water Status ◽  
Field Trials ◽  
Climatic Conditions ◽  
Soil P ◽  
Crop Type ◽  
Foliar Phosphorus ◽  
The Usa ◽  
Added Benefit ◽  
Phosphorus Fertilisation

Although not commonly used in dryland cropping systems to date, foliar phosphorus (P) fertilisation may allow a tactical response to prevailing seasonal climatic conditions, with the added benefit of reduced input costs at sowing. However, variable outcomes have been reported from field trials predominantly conducted in the USA, and to a lesser degree in Australia. The effectiveness of foliar P is dependent on soil P status, soil water status, crop type, fertiliser formulation and prevailing climatic conditions. This review argues that the potential of foliar P fertilisation in Australian dryland cereal cropping could be enhanced by altering formulations for enhanced leaf penetration using adjuvants, and by accurately assessing the responsiveness of sites before application. This review demonstrates that it is important to use appropriate techniques such as isotopic labelling, to measure the efficacy and mode of action of foliar formulations.

scholarly journals Evaluation of Sprinkler Irrigation Evaporation Losses in Ilaro, Ogun State, South Western Nigeria

2021 ◽  
Vol 2 (1) ◽  
pp. 47-59
Author(s):  
Samuel Dare OLUWAGBAYIDE ◽  
Olugbenga FASANU ◽  
Ajayi Johnson OLORUNTADE
Keyword(s):  
Wind Velocity ◽  
Air Temperature ◽  
Climatic Factors ◽  
Sprinkler Irrigation ◽  
Climatic Conditions ◽  
Operating Pressure ◽  
Ogun State ◽  
Evaporation Losses ◽  
Pressure Medium ◽  
Rate Of Evaporation

Under the prevailing climate change the world is currently facing, efficient irrigation water management is essential to ensure food security, especially in countries with similar climate to Nigeria. Hence, this study was undertaken at the Research Farm of Federal Polytechnic, Ilaro, Ogun State, Nigeria to evaluate evaporation losses during sprinkler irrigation between March and July 2019. Experiments were performed using 360 rotating sprinkler and single nozzle of diameter 3 mm, while due cognizance was taken of the prevailing climatic conditions. Three operating pressures, namely, 50 kPa, 100 kPa and 150 kPa, representing low pressure, medium pressure and high pressure, respectively, were used. The results showed that operating pressures influence droplet sizes, droplet heights and flow rate during the experiment. In addition, it was observed that at operating pressures of 50 kPa, 100 kPa and 150 kPa, mean percentage of evaporation losses were 8.88%, 13.21% and 16.46%, respectively, indicating that evaporation losses increased with increasing operating pressure. Further analysis showed that percentage evaporation losses increased at higher relative humidity, thereby emphasizing the predominance of air temperature and wind velocity as climatic variable influencing sprinkler evaporation losses. The relationship between wind velocity (Vw ) and air temperature (Ta) and to predict evaporation losses (E ) was a function of E = 7.968Vw + 0.393Ta – 19.977. Therefore, it was concluded that, both climatic factors and operating pressures influence the rate of evaporation losses during sprinkler irrigation, adequate attention should be paid to variation of climatic variables since sprinklers are sold with their specified operating pressures.

scholarly journals Effect of cultivar, location and method of cultivation on the content of chlorogenic acid in potatoes with different flesh colour

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 465-471 ◽  
Author(s):  
K. Hamouz ◽  
J. Lachman ◽  
K. Pazderů ◽  
K. Hejtmánková ◽  
J. Cimr ◽  
...  
Keyword(s):  
High Altitude ◽  
Chlorogenic Acid ◽  
Conventional Treatment ◽  
Field Trials ◽  
Climatic Conditions ◽  
Flesh Colour ◽  
Fresh Matter ◽  
Organic Cultivation ◽  
Organically Grown

In precise field trials in the years 2010 and 2011 the effect of genotype and location in cultivars with yellow, white, purple or red flesh on the content of chlorogenic acid (CA) and in 2011 and 2012 the effect of organic cultivation were evaluated. The results show a statistically significant effect of genotype to CA content, which ranged from 74.0 mg/kg fresh matter (FM) (Agria) to 825 mg/kg FM (Vitelotte). Demonstrable effect of flesh colour on CA content between cultivars with coloured flesh was found (430 mg/kg FM) in comparison with cultivars with yellow or white flesh (71.1 mg/kg FM). For cultivars with coloured flesh rather the genotype specific cultivar ruled than the purple or red flesh colour. In terms of the influence of location, higher CA levels were found on warm locations with frequent periods of drought in comparison with locations of high altitude climatic conditions which are favourable for potato cultivation. In the organically grown potatoes significantly higher levels of CA were found as compared with conventional treatment.

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