Ā. Jansons, J. Dzenis, R. Matisons, Valters Samariks, B. Jansone
The Scots pine (Pinus sylvestris L.) is the second-most widely used tree species in forestry in Latvia and is the only species used for afforestation on nutrient poor soils that cover considerable forest land in Latvia. Several studies have shown that, in such conditions, the lodgepole pine (Pinus contorta var. latifolia) may be more productive in terms of biomass and yield. It is important to consider climate change studies to assess the potential for a larger-scale use of the lodgepole pine in forestry. The aim was to assess the intra-annual height growth patterns of both species, the differences between them, and the influence of meteorological parameters on their height growth. Their height growth was monitored on a weekly basis in two sampling sites in central Latvia, and the height increment curves were described by Gompertz’s model. The height growth dynamics of individual trees and species differed notably, indicating the potential for the selection of the best-adapted genotypes. Our results indicate that the early onset of the active growth phase might be the most important factor determining the total height increment for both species. Temperature-related meteorological parameters were the only ones with a statistically significant influence on pines height growth and only when at least one of the variables were standardised prior to the analysis. A temperature increase had a slightly stronger positive effect on the growth of the lodgepole pine, indicating that it might be suitable for more intensive use in forestry under the climate change scenarios for Latvia.
苏格兰松(Pinus sylvestris L.)是拉脱维亚林业中第二大最广泛使用的树种，也是拉脱维亚覆盖大量林地的营养贫乏土壤上唯一用于造林的树种。几项研究表明，在这种条件下，黑松(Pinus contorta var. latifolia)在生物量和产量方面可能更有生产力。重要的是要考虑气候变化研究，以评估在林业中大规模使用黑松的潜力。目的是评估两种树种的年内高度生长模式，它们之间的差异，以及气象参数对它们高度生长的影响。在拉脱维亚中部的两个采样点每周监测它们的高度增长情况，并用Gompertz模型描述高度增长曲线。不同树种间的株高生长动态差异显著，表明存在选择最佳适应基因型的潜力。结果表明，生长期的提前到来可能是决定两种树种总高度增长量的最重要因素。与温度相关的气象参数是唯一对松树高度生长有统计显著影响的参数，并且只有在分析之前至少对其中一个变量进行了标准化。温度升高对黑松生长的积极影响略强，表明在拉脱维亚气候变化情景下，黑松可能适合更密集地用于林业。
{"title":"Intra-annual height growth dynamics of Scots and lodgepole pines and its relationship with meteorological parameters in central Latvia.","authors":"Ā. Jansons, J. Dzenis, R. Matisons, Valters Samariks, B. Jansone","doi":"10.15159/AR.20.002","DOIUrl":"https://doi.org/10.15159/AR.20.002","url":null,"abstract":"The Scots pine (Pinus sylvestris L.) is the second-most widely used tree species in forestry in Latvia and is the only species used for afforestation on nutrient poor soils that cover considerable forest land in Latvia. Several studies have shown that, in such conditions, the lodgepole pine (Pinus contorta var. latifolia) may be more productive in terms of biomass and yield. It is important to consider climate change studies to assess the potential for a larger-scale use of the lodgepole pine in forestry. The aim was to assess the intra-annual height growth patterns of both species, the differences between them, and the influence of meteorological parameters on their height growth. Their height growth was monitored on a weekly basis in two sampling sites in central Latvia, and the height increment curves were described by Gompertz’s model. The height growth dynamics of individual trees and species differed notably, indicating the potential for the selection of the best-adapted genotypes. Our results indicate that the early onset of the active growth phase might be the most important factor determining the total height increment for both species. Temperature-related meteorological parameters were the only ones with a statistically significant influence on pines height growth and only when at least one of the variables were standardised prior to the analysis. A temperature increase had a slightly stronger positive effect on the growth of the lodgepole pine, indicating that it might be suitable for more intensive use in forestry under the climate change scenarios for Latvia.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"410-421"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66968144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Farmers operate in a turbulent environment that includes international competition, weather conditions and animal behaviour, for example, and is difficult for them to control. However, economy and ...
农民在一个动荡的环境中经营，包括国际竞争、天气条件和动物行为，例如，他们很难控制。然而，经济和……
{"title":"Lean-inspired development work in agriculture: Implications for the work environment","authors":"K. Andersson, A. Rydberg, J. Eklund","doi":"10.15159/AR.20.043","DOIUrl":"https://doi.org/10.15159/AR.20.043","url":null,"abstract":"Farmers operate in a turbulent environment that includes international competition, weather conditions and animal behaviour, for example, and is difficult for them to control. However, economy and ...","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"324-345"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66968783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. A. Damasceno, J. Monge, J.A.C. Nascimento, R. R. Andrade, M. Barbari, J. Saraz, G. Ferraz
Milk production is increasingly modernized as a result of the growing demand for food around the world. Improvements in livestock facilities are observed, with a large increase in the use of feedlot systems such as the Compost Dairy Barn. Increasing milk production in confinement systems has also raised concerns such as the management of wastes (water, faeces and urine) from the system, which has become one of the most important issues in the intensive dairy farms. The aim of this work was to estimate the amount of manure present in compost dairy barn systems in order to size the manure storage. The study was conducted at four compost dairy barns in southern Minas Gerais, Brazil. These compost barns had different bedding materials and dimensions. In each farm, data on milk yield and quality (daily production, fat and protein content), animal weight and amount of feed ingested by the animals were collected. Total-day manure delivered by the cows in the feeding alley and milking parlour was piled up together and weighed. Based on the results, it was observed that, in the compost dairy barns, only part of the total manure produced per day was delivered in the milking parlour (1.6 and 2.0%) and in the feed alley (27.6 to 49.3%). These results are very important for designers for the proper manure management system design of the dairy farms.
{"title":"Estimate of manure present in compost dairy barn systems for sizing of manure storage","authors":"F. A. Damasceno, J. Monge, J.A.C. Nascimento, R. R. Andrade, M. Barbari, J. Saraz, G. Ferraz","doi":"10.15159/AR.20.105","DOIUrl":"https://doi.org/10.15159/AR.20.105","url":null,"abstract":"Milk production is increasingly modernized as a result of the growing demand for food around the world. Improvements in livestock facilities are observed, with a large increase in the use of feedlot systems such as the Compost Dairy Barn. Increasing milk production in confinement systems has also raised concerns such as the management of wastes (water, faeces and urine) from the system, which has become one of the most important issues in the intensive dairy farms. The aim of this work was to estimate the amount of manure present in compost dairy barn systems in order to size the manure storage. The study was conducted at four compost dairy barns in southern Minas Gerais, Brazil. These compost barns had different bedding materials and dimensions. In each farm, data on milk yield and quality (daily production, fat and protein content), animal weight and amount of feed ingested by the animals were collected. Total-day manure delivered by the cows in the feeding alley and milking parlour was piled up together and weighed. Based on the results, it was observed that, in the compost dairy barns, only part of the total manure produced per day was delivered in the milking parlour (1.6 and 2.0%) and in the feed alley (27.6 to 49.3%). These results are very important for designers for the proper manure management system design of the dairy farms.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"1213-1219"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66969727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recycling and disposal are one of the most complicated topics in the lifecycle of a mechanism, especially in case of previous generations of machines that were designed without taking any care of post exploitation period. In the current work, the ‘feasibility points’ of recycling units, methods of recycling as well as pricing formation for recycling materials, reviewed and proposed by several world universities and scientific bureaus and applied by major world brands have been analysed. The general principles that should be rated as a basis when designing and creating new mechanisms, as well as the actions which we consider as a necessary supplement to the existing rules of the lifecycle of assemblies and which should be applied in practice, were introduced by authors in the ‘Management of parts and components for units and assemblies in mechanical engineering industry and its impact on the environment’. It was discovered that even modern assemblies, not to mention previous generations, are being designed without taking into consideration any possibilities of easy recycling the used materials. The number of components of mechanisms, which are being repaired as assemblies, is continuously increasing, while maintainability and repairability of separate parts is decreasing. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed. Thus, using the fast-moving parts that in post operational period can be easily detailed by type of a material will ensure more efficient consumption of natural resources. Our research and developments significantly reduce the costs of recycling and these materials become competitive comparing to the new ones. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed.
{"title":"New approach for recycling spare parts, components and assemblies.","authors":"V. Mitrofanovs, Ē. Geriņš, I. Boiko","doi":"10.15159/AR.20.141","DOIUrl":"https://doi.org/10.15159/AR.20.141","url":null,"abstract":"Recycling and disposal are one of the most complicated topics in the lifecycle of a mechanism, especially in case of previous generations of machines that were designed without taking any care of post exploitation period. In the current work, the ‘feasibility points’ of recycling units, methods of recycling as well as pricing formation for recycling materials, reviewed and proposed by several world universities and scientific bureaus and applied by major world brands have been analysed. The general principles that should be rated as a basis when designing and creating new mechanisms, as well as the actions which we consider as a necessary supplement to the existing rules of the lifecycle of assemblies and which should be applied in practice, were introduced by authors in the ‘Management of parts and components for units and assemblies in mechanical engineering industry and its impact on the environment’. It was discovered that even modern assemblies, not to mention previous generations, are being designed without taking into consideration any possibilities of easy recycling the used materials. The number of components of mechanisms, which are being repaired as assemblies, is continuously increasing, while maintainability and repairability of separate parts is decreasing. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed. Thus, using the fast-moving parts that in post operational period can be easily detailed by type of a material will ensure more efficient consumption of natural resources. Our research and developments significantly reduce the costs of recycling and these materials become competitive comparing to the new ones. Taking into account the state of the art in the field, the new approach for promoting the reusing natural resources and decreasing the harmful effects of obsolete components of mechanisms on the environment is proposed.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"923-930"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66970656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper demonstrates the applicability of several statistical methods to the analysis and interpretation of the average rapeseed yield data. It proves our hypothesis that the general trend of rapeseed yield variations in Ukraine during 1991–2017 occurred due to agro-economic and agro-technological factors, which are the determinants of the revealed general trend. The temporal trend of rapeseed yield in most administrative districts can be described by a fourth-degree polynomial, namely, its characteristic points enabled us to describe and interpret the dynamics of rapeseed yields. The absolute term of the polynomial shows the initial conditions of the process, and its mapping allows us to identify the areas with the most favorable soil-climatic conditions for the rapeseed cultivation. Indicators of the maximum rate of growth and decrease of yields are the markers of stability of agro-ecosystems to the external influences. Therefore, the mapping of the maximum rate of decline and increase of yields reveal areas in which yields respond rapidly (increasing / falling) to the changes in agro-economic and agro-technological conditions, as well as areas where yields are more stable and change gradually. Thus, the form of the yield trend is determined by the influence of agro-technological and agro-economic factors, whose contribution to the fluctuation in rapeseed yields varies from 53% to 90%.
{"title":"The spatio-temporal trend of rapeseed yields in Ukraine as a marker of agro-economic factors influence","authors":"A. Zymaroieva, O. Zhukov, T. Fedonyuk, T. Pinkina","doi":"10.15159/AR.20.119","DOIUrl":"https://doi.org/10.15159/AR.20.119","url":null,"abstract":"The paper demonstrates the applicability of several statistical methods to the analysis and interpretation of the average rapeseed yield data. It proves our hypothesis that the general trend of rapeseed yield variations in Ukraine during 1991–2017 occurred due to agro-economic and agro-technological factors, which are the determinants of the revealed general trend. The temporal trend of rapeseed yield in most administrative districts can be described by a fourth-degree polynomial, namely, its characteristic points enabled us to describe and interpret the dynamics of rapeseed yields. The absolute term of the polynomial shows the initial conditions of the process, and its mapping allows us to identify the areas with the most favorable soil-climatic conditions for the rapeseed cultivation. Indicators of the maximum rate of growth and decrease of yields are the markers of stability of agro-ecosystems to the external influences. Therefore, the mapping of the maximum rate of decline and increase of yields reveal areas in which yields respond rapidly (increasing / falling) to the changes in agro-economic and agro-technological conditions, as well as areas where yields are more stable and change gradually. Thus, the form of the yield trend is determined by the influence of agro-technological and agro-economic factors, whose contribution to the fluctuation in rapeseed yields varies from 53% to 90%.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"1584-1596"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66971054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Pihlap, A. Annuk, M. Lehtonen, S. Muiste, A. Tooming, Alo Allik
In the retrofitting of older buildings with central heating into nearly zero-energy buildings more and more air to water heat pumps are used. These heat pumps are normally connected to heating systems, producing heat only on demand. The greatest demand for heat occurs when the outside temperature and therefore the COP of the pump is lowest. Outside temperature varies during the day, meaning it is possible to save energy by producing and storing heat in a situation where the COP is higher. To determine the periods with higher COP values weather forecast data and COP curves are used. The data enables to rank and select time periods for heat production. This in conjunction with the heat demand curve of the building enables to create an operation schedule for the heat pump. The aim of the study is to develop heat pump control methods for renovated buildings to comply with nearly zero energy building codes. Dependant on the heat pump and weather conditions, up to 10% of the electricity demand for heating can be decreased.
{"title":"A control method for increasing the heat usage efficiency of nearly-zero-energy buildings with heat pumps","authors":"H. Pihlap, A. Annuk, M. Lehtonen, S. Muiste, A. Tooming, Alo Allik","doi":"10.15159/AR.20.032","DOIUrl":"https://doi.org/10.15159/AR.20.032","url":null,"abstract":"In the retrofitting of older buildings with central heating into nearly zero-energy buildings more and more air to water heat pumps are used. These heat pumps are normally connected to heating systems, producing heat only on demand. The greatest demand for heat occurs when the outside temperature and therefore the COP of the pump is lowest. Outside temperature varies during the day, meaning it is possible to save energy by producing and storing heat in a situation where the COP is higher. To determine the periods with higher COP values weather forecast data and COP curves are used. The data enables to rank and select time periods for heat production. This in conjunction with the heat demand curve of the building enables to create an operation schedule for the heat pump. The aim of the study is to develop heat pump control methods for renovated buildings to comply with nearly zero energy building codes. Dependant on the heat pump and weather conditions, up to 10% of the electricity demand for heating can be decreased.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"958-968"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66968635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Rudzītis, M. Madissoo, M. Gailis, J. Kreicbergs
{"title":"Research on energy efficiency of pneumatic cylinder for pneumatic vehicle motor.","authors":"J. Rudzītis, M. Madissoo, M. Gailis, J. Kreicbergs","doi":"10.15159/AR.20.048","DOIUrl":"https://doi.org/10.15159/AR.20.048","url":null,"abstract":"","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"823-841"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66969077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Bartzialis, K. Giannoulis, E. Skoufogianni, A. Lavdis, G. Zalaoras, G. Charvalas, N. Danalatos
The objective of this study was to examine the effect on the dry biomass yield of two dfferent sorghum hybrids (H1 and H2) under five different N-fertilization levels (0, 70, 140, 210 and 280 kg ha) in a soil which was formed by lacustrine deposits of Karla Lake and is characterized from the downward movement of calcium carbonate from the surface horizons due to leaching (Fluventic Xerochrept) during 2017. The results demonstrated a significant effect (P < 0.05) of fertilization only for one hybrid. Biomass yield ranged from 22.2 to 37.5 t ha. For both hybrids, sorghum accumulated a high amount of biomass in stems. Dry stem/total biomass ratio was rather constant throughout the different fertilization treatments achieving 81.6 and 77.5% for the first (H1) and the second hybrid (H2), respectively. The second hybrid (H2) had a higher percentage of leaf biomass (20.1 vs. 13.8%) than the first (H1), but lagged behind in seed production (2.4 vs. 4.6%). Biomass dry matter partitioning and total dry weight are important selection criteria for energy crops, due to different gross calorific value and ash content but also because of the different economic importance they may have e.g. the seed is also used as animal feed. The above high biomass yields of sorghum, confirming the high potential of this crop, should be taken into serious consideration regarding land use planning, but further investigation for the gross calorific value and the ash content is needed as well as biomass characteristics that are quite important in case to improve the combustion process.
本研究的目的是研究5种不同施氮水平(0、70、140、210和280 kg ha)对卡拉湖湖泊沉积物土壤中两种不同高粱杂交品种(H1和H2)干生物量产量的影响，该土壤的特征是2017年由于淋溶(Fluventic Xerochrept)导致碳酸钙从表层向下移动。结果表明，只对一种杂交品种施肥效果显著(P < 0.05)。生物量产量在22.2 ~ 37.5 t / h之间。在这两个杂交品种中，高粱在茎部积累了大量的生物量。在不同的施肥处理中，干茎/总生物量比基本不变，第一杂种(H1)和第二杂种(H2)的干茎/总生物量比分别达到81.6和77.5%。2个杂种(H2)的叶片生物量比(20.1%比13.8%)高于1个杂种(H1)，但在制种方面落后(2.4比4.6%)。生物质干物质分配和总干重是能源作物的重要选择标准，因为它们的总热值和灰分含量不同，但也因为它们可能具有不同的经济重要性，例如种子也可用作动物饲料。高粱的上述高生物量产量证实了该作物的高潜力，应在土地利用规划中予以认真考虑，但还需要进一步研究其总热值和灰分含量，以及对改善燃烧过程非常重要的生物质特性。
{"title":"Sorghum dry biomass yield for solid bio-fuel production affected by different N-fertilization rates.","authors":"D. Bartzialis, K. Giannoulis, E. Skoufogianni, A. Lavdis, G. Zalaoras, G. Charvalas, N. Danalatos","doi":"10.15159/AR.20.072","DOIUrl":"https://doi.org/10.15159/AR.20.072","url":null,"abstract":"The objective of this study was to examine the effect on the dry biomass yield of two dfferent sorghum hybrids (H1 and H2) under five different N-fertilization levels (0, 70, 140, 210 and 280 kg ha) in a soil which was formed by lacustrine deposits of Karla Lake and is characterized from the downward movement of calcium carbonate from the surface horizons due to leaching (Fluventic Xerochrept) during 2017. The results demonstrated a significant effect (P < 0.05) of fertilization only for one hybrid. Biomass yield ranged from 22.2 to 37.5 t ha. For both hybrids, sorghum accumulated a high amount of biomass in stems. Dry stem/total biomass ratio was rather constant throughout the different fertilization treatments achieving 81.6 and 77.5% for the first (H1) and the second hybrid (H2), respectively. The second hybrid (H2) had a higher percentage of leaf biomass (20.1 vs. 13.8%) than the first (H1), but lagged behind in seed production (2.4 vs. 4.6%). Biomass dry matter partitioning and total dry weight are important selection criteria for energy crops, due to different gross calorific value and ash content but also because of the different economic importance they may have e.g. the seed is also used as animal feed. The above high biomass yields of sorghum, confirming the high potential of this crop, should be taken into serious consideration regarding land use planning, but further investigation for the gross calorific value and the ash content is needed as well as biomass characteristics that are quite important in case to improve the combustion process.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"36 1","pages":"1147-1153"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66969297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Fagundes, F. A. Damasceno, R. R. Andrade, J. Saraz, M. Barbari, F. Vega, J.A.C. Nascimento
In the pursuit of high milk productivity, producers are using confinement systems in order to improve performance and animal welfare. Among the housing systems, the Compost bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows move freely. Generally this area is covered with carbon source material (such as sawdust or fine dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures the aerobic composting process. The ventilation in these facilities has the function of dehumidifying the air, improving the air quality, drying the bedding, improving the thermal comfort conditions of the confined animals. This work aimed at validating a computational model using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows generated by different forced ventilation systems used in CBP barns. Two CBP barns were compared with different ventilation systems: high volume low speed (HVLS) and low volume high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict the flows generated by both types of fans. It was concluded that the use of HVLS fans produced a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation in tropical conditions is necessary for the proper functioning of the system. In this study, the systems used promoted the increase in air speed to levels close to adequate.
{"title":"Comparison of airflow homogeneity in compost dairy barns with different ventilation systems using the CFD model.","authors":"B. Fagundes, F. A. Damasceno, R. R. Andrade, J. Saraz, M. Barbari, F. Vega, J.A.C. Nascimento","doi":"10.15159/AR.20.106","DOIUrl":"https://doi.org/10.15159/AR.20.106","url":null,"abstract":"In the pursuit of high milk productivity, producers are using confinement systems in order to improve performance and animal welfare. Among the housing systems, the Compost bedded-pack barns (CBP) stand out. In these barns a bedding area is provided inside, where cows move freely. Generally this area is covered with carbon source material (such as sawdust or fine dry wood shavings) which together with manure, thanks a regular mechanically stirring, ensures the aerobic composting process. The ventilation in these facilities has the function of dehumidifying the air, improving the air quality, drying the bedding, improving the thermal comfort conditions of the confined animals. This work aimed at validating a computational model using Computational Fluid Dynamics (CFD) to determine the best homogeneity of airflows generated by different forced ventilation systems used in CBP barns. Two CBP barns were compared with different ventilation systems: high volume low speed (HVLS) and low volume high-speed (LVHS) fans. The results showed that the proposed model was satisfactory to predict the flows generated by both types of fans. It was concluded that the use of HVLS fans produced a more homogeneous airflow when compared to LVHS fans. The use of mechanical ventilation in tropical conditions is necessary for the proper functioning of the system. In this study, the systems used promoted the increase in air speed to levels close to adequate.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"788-796"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66969754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The attention for the replacement of peat in growing substrates is increasing due to its environmental and economic advantages. The aim of the present work was to evaluate the impact of peat substitution by new type olive mill pomace and its compost on the vegetative activity of potted olive trees. A new type of humid pomace (hP) derived from an innovative two phase extraction system and its derived compost (C-hP) are used as total or partial (50% vol/vol) replacement of peat in olive growing substrate. The main chemical characteristics (moisture, water extractable organic carbon, total nitrogen, C/N ratio and electrical conductivity) of the hP and C-hP were measured. In order to evaluate the effects of the peat substitution on the plants vegetative activity, measurements of mortality, plant height, leaf net photosynthesis and plant growth (through final destructive measurements) were carried out. The use of hP resulted in a significant increase of the salinity of the substrate. The water extractable organic carbon concentration was higher in all substrates where peat was ewplaced and in particular when C-hP was used. The total replacement of peat with hP caused 100% mortality of the plants while C-hP can substitute peat up to 50% without causing a significative reduction of the final plant growth.
{"title":"The sustainable reuse of compost from a new type of olive mill pomace in replacing peat for potted olive tree","authors":"L. Regni, D. Pezzolla, G. Gigliotti, P. Proietti","doi":"10.15159/AR.20.129","DOIUrl":"https://doi.org/10.15159/AR.20.129","url":null,"abstract":"The attention for the replacement of peat in growing substrates is increasing due to its environmental and economic advantages. The aim of the present work was to evaluate the impact of peat substitution by new type olive mill pomace and its compost on the vegetative activity of potted olive trees. A new type of humid pomace (hP) derived from an innovative two phase extraction system and its derived compost (C-hP) are used as total or partial (50% vol/vol) replacement of peat in olive growing substrate. The main chemical characteristics (moisture, water extractable organic carbon, total nitrogen, C/N ratio and electrical conductivity) of the hP and C-hP were measured. In order to evaluate the effects of the peat substitution on the plants vegetative activity, measurements of mortality, plant height, leaf net photosynthesis and plant growth (through final destructive measurements) were carried out. The use of hP resulted in a significant increase of the salinity of the substrate. The water extractable organic carbon concentration was higher in all substrates where peat was ewplaced and in particular when C-hP was used. The total replacement of peat with hP caused 100% mortality of the plants while C-hP can substitute peat up to 50% without causing a significative reduction of the final plant growth.","PeriodicalId":7924,"journal":{"name":"Agronomy research","volume":"18 1","pages":"1444-1454"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66970904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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