Pub Date : 2020-02-01DOI: 10.1590/1807-1929/agriambi.v24n2p128-133
T. S. Telles, A. Righetto, Marco A. P. Lourenço, G. M. Barbosa
ABSTRACT The no-tillage system participatory quality index aims to evaluate the quality and efficiency of soil management under no-tillage systems and consists of a weighted sum of eight indicators: intensity of crop rotation, diversity of crop rotation, persistence of crop residues in the soil surface, frequency of soil tillage, use of agricultural terraces, evaluation of soil conservation, balance of soil fertilization and time of adoption of the no-tillage system. The aim of this study was to assess the extent to which these indicators correlate with the no-tillage system participatory quality index and to characterize the farmers who participated in the research. The data used were provided by ITAIPU Binacional for the indicators of the no-tillage system participatory quality index II. Descriptive analyses were performed, and the Pearson correlation coefficient between the index and each indicator was calculated. To assess the relationship between the indicators and the farmers’ behavior toward the indicators, principal component analysis and cluster analysis were performed. Although all correlations are significant at p-value ≤ 0.05, some correlations are weak, indicating a need for improvement of the index. The principal component analysis identified three principal components, which explained 66% of the variability of the data, and the cluster analysis separated the 121 farmers into five groups. It was verified that the no-tillage system participatory quality index II has some limitations and should therefore be reevaluated to increase its efficiency as an indicator of the quality of the no-tillage system.
{"title":"No-tillage system participatory quality index","authors":"T. S. Telles, A. Righetto, Marco A. P. Lourenço, G. M. Barbosa","doi":"10.1590/1807-1929/agriambi.v24n2p128-133","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n2p128-133","url":null,"abstract":"ABSTRACT The no-tillage system participatory quality index aims to evaluate the quality and efficiency of soil management under no-tillage systems and consists of a weighted sum of eight indicators: intensity of crop rotation, diversity of crop rotation, persistence of crop residues in the soil surface, frequency of soil tillage, use of agricultural terraces, evaluation of soil conservation, balance of soil fertilization and time of adoption of the no-tillage system. The aim of this study was to assess the extent to which these indicators correlate with the no-tillage system participatory quality index and to characterize the farmers who participated in the research. The data used were provided by ITAIPU Binacional for the indicators of the no-tillage system participatory quality index II. Descriptive analyses were performed, and the Pearson correlation coefficient between the index and each indicator was calculated. To assess the relationship between the indicators and the farmers’ behavior toward the indicators, principal component analysis and cluster analysis were performed. Although all correlations are significant at p-value ≤ 0.05, some correlations are weak, indicating a need for improvement of the index. The principal component analysis identified three principal components, which explained 66% of the variability of the data, and the cluster analysis separated the 121 farmers into five groups. It was verified that the no-tillage system participatory quality index II has some limitations and should therefore be reevaluated to increase its efficiency as an indicator of the quality of the no-tillage system.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"162 1","pages":"128-133"},"PeriodicalIF":1.2,"publicationDate":"2020-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74585441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p372-378
P. Souza, V. Farias, J. Pinto, H. Nunes, E. Souza, C. Fraisse
ABSTRACT The cowpea bean presents low productivity in the Pará state, Brazil, due to low soil fertility and climatic adversity, mainly water deficiency. The aim of this study was to evaluate the yield gap of cowpea bean in northeast of Para state in response to water deficit during its reproductive phase. The experiment was carried out in Castanhal, PA, Brazil, during 2015 and 2016. A randomized block design with six repetitions and four treatments was used; where T1 consisted of 100% replacement of the crop evapotranspiration (ETc), T2 to 50%, T3 to 25% and T4 without irrigation, in the reproductive phase. The yield was determined at R9 stage. The simulations with the SARRAZON model were carried out with different sowing dates. The total deficiencies in the reproductive phase were spatialized considering the 30 locations in order to assess the temporal and spatial seasonality of water availability and the sowing period in the study region. The cowpea bean was sensitive to soil water availability with considerable reductions in productivity due to the increase in water deficit compared to the treatment T1 (100% ETc). When water deficits reached more than 47 mm, there were yield gaps over 20%. According to the spatial variability of simulated water deficiency, the sowing of cowpea bean in regions located above 2° latitude may extend until June 20 without showing high yield gaps.
在巴西帕尔州，由于土壤肥力低和气候逆境(主要是缺水)，豇豆产量低。本研究的目的是评价帕拉州东北部豇豆在生育期对水分亏缺的响应。该实验于2015年至2016年在巴西宾夕法尼亚州Castanhal进行。采用随机区组设计，6个重复，4个处理;其中T1为100%替代作物蒸散量(ETc)， T2 ~ 50%， T3 ~ 25%， T4不灌溉。在R9期测定产量。采用SARRAZON模型对不同播期的土壤进行了模拟。为了评价研究区水分有效性和播种期的时空季节性，对30个地点的生殖期总亏缺进行了空间化处理。豇豆对土壤水分有效性敏感，与T1(100%等)处理相比，由于水分亏缺增加，豇豆的生产力显著降低。当水分亏缺大于47 mm时，产量缺口超过20%。根据模拟缺水的空间变异性，2°纬度以上地区豇豆播种期可能延续至6月20日，且无高产间隙。
{"title":"Yield gap in cowpea plants as function of water déficits during reproductive stage","authors":"P. Souza, V. Farias, J. Pinto, H. Nunes, E. Souza, C. Fraisse","doi":"10.1590/1807-1929/agriambi.v24n6p372-378","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n6p372-378","url":null,"abstract":"ABSTRACT The cowpea bean presents low productivity in the Pará state, Brazil, due to low soil fertility and climatic adversity, mainly water deficiency. The aim of this study was to evaluate the yield gap of cowpea bean in northeast of Para state in response to water deficit during its reproductive phase. The experiment was carried out in Castanhal, PA, Brazil, during 2015 and 2016. A randomized block design with six repetitions and four treatments was used; where T1 consisted of 100% replacement of the crop evapotranspiration (ETc), T2 to 50%, T3 to 25% and T4 without irrigation, in the reproductive phase. The yield was determined at R9 stage. The simulations with the SARRAZON model were carried out with different sowing dates. The total deficiencies in the reproductive phase were spatialized considering the 30 locations in order to assess the temporal and spatial seasonality of water availability and the sowing period in the study region. The cowpea bean was sensitive to soil water availability with considerable reductions in productivity due to the increase in water deficit compared to the treatment T1 (100% ETc). When water deficits reached more than 47 mm, there were yield gaps over 20%. According to the spatial variability of simulated water deficiency, the sowing of cowpea bean in regions located above 2° latitude may extend until June 20 without showing high yield gaps.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"42 1","pages":"372-378"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88237223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n1p3-7
H. M. P. Rosa, Bruno S. Emerick
The present paper aims to present the analysis and comparison of results of computational simulations using Computational Fluids Dynamics (CFD) in impellers of centrifugal pump. Three impellers were simulated: 1) original impeller, 2) original impeller with splitter blades at outlet; 3) original impeller with splitter blades at inlet. The splitters occupied 30% of the length of the main blades. They were simulated using the ANSYS-CFX software system in 1500 rpm rotational speed and at different flow rates. The turbulence model assumed was the Shear Stress Transport (SST). The results were used to build impeller blade head curves, besides the presentation of pressure distribution and streamline behaviour inside the impeller. It was verified that the insertion of the splitter blades reduced the impeller blade head, mainly the impeller with outlet splitter, whose reduction was more intense.
{"title":"CFD simulation on centrifugal pump impeller with splitter blades","authors":"H. M. P. Rosa, Bruno S. Emerick","doi":"10.1590/1807-1929/agriambi.v24n1p3-7","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n1p3-7","url":null,"abstract":"The present paper aims to present the analysis and comparison of results of computational simulations using Computational Fluids Dynamics (CFD) in impellers of centrifugal pump. Three impellers were simulated: 1) original impeller, 2) original impeller with splitter blades at outlet; 3) original impeller with splitter blades at inlet. The splitters occupied 30% of the length of the main blades. They were simulated using the ANSYS-CFX software system in 1500 rpm rotational speed and at different flow rates. The turbulence model assumed was the Shear Stress Transport (SST). The results were used to build impeller blade head curves, besides the presentation of pressure distribution and streamline behaviour inside the impeller. It was verified that the insertion of the splitter blades reduced the impeller blade head, mainly the impeller with outlet splitter, whose reduction was more intense.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"25 1","pages":"3-7"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81454431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p385-393
R. D. Mantai, J. G. D. Silva, M. Binelo, A. Sausen, Denis Sidinei Rossi, Janiele S. Corso
ABSTRACT Among oat inflorescence components there are different magnitudes of contribution to expression of grain and industrial productivity by nitrogen stimulation. Thus, it was proposed to size and interpret the contribution and dynamics of the relationships of oat inflorescence components with grain and industrial yield by N-fertilizer stimulation, partitioning correlation values into direct and indirect effects by path diagnosis, strengthened by the joint analysis of different agricultural years. The study was carried out from 2011 to 2016, in the municipality of Augusto Pestana, RS, Brazil, in a randomized block design with four repetitions in a 4 x 2 factorial scheme for nitrogen doses (0, 30, 60 and 120 kg ha-1), using oat cultivars (Barbarasul and Brisasul) in soybean/oat and corn/oat systems. In the soybean/oat system, the mass and the number of panicle spikelets and the mass of panicle grains, contributed more to promoting changes by the increase of nitrogen. In the corn/oat system, the variables with the highest contribution are the mass and the number of panicle spikelets. The increase in panicle grain mass and in panicle harvest index increases grain yield, however, together with the number of panicle grains, they reduce industrial productivity, regardless of the cultivation system.
在燕麦花序组分中，氮素刺激对籽粒和工业生产力的表达有不同程度的贡献。因此，我们提出通过氮肥刺激，将相关值划分为直接效应和间接效应，并通过不同农业年的联合分析来强化相关值，以确定和解释燕麦花序组分对粮食和工业产量的贡献和动态关系。该研究于2011年至2016年在巴西RS奥古斯托佩斯塔纳市进行，采用随机区组设计，在4 × 2因子方案中重复4次氮剂量(0,30,60和120 kg hm -1)，使用大豆/燕麦和玉米/燕麦系统中的燕麦品种(Barbarasul和Brisasul)。在大豆/燕麦体系中，施氮量的增加对穗粒质量、穗粒数和穗粒质量的促进作用更大。在玉米/燕麦系统中，贡献最大的变量是穗粒质量和穗粒数。穗粒质量的增加和穗收获指数的提高提高了粮食产量，但与穗粒数一起降低了工业生产率，与栽培制度无关。
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Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n1p24-30
João G. A. Lima, J. M. Sánchez, J. Piqueras, José Espínola Sobrinho, Paula C. Viana, Aline da S. Alves
The estimate of the actual surface evapotranspiration (ET) contributes to quantifying the water needs of crops. An alternative to the use of lysimeter for an accurate estimation of water needs, which has proved to be of great value in recent years, is the use of remote sensing combined with models based on surface energy balance. There is wide variety of models that can be classified into two types: one-source models, such as the Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) algorithm, or two-source models, such as the Simplified Two-Source Energy Balance (STSEB). The objective of this study was to analyze how METRIC and STSEB can be used to estimate ET, in comparison with the lysimeter data, for the different stages of development of the sorghum crop in Apodi, RN, Brazil. The accuracy of both models in the daily ET estimation for the semi-arid conditions of the experiment, with RMSE values of 0.8 and of 0.7 mm d-1 through METRIC and STSEB, respectively, is considered acceptable for irrigation management purposes. The errors obtained with METRIC at an instantaneous scale were 60, 50, 130 and 5 W m-2 for Rn, LE, H and G, respectively, on the other hand, using STSEB these errors were of 40, 70, 120 and 21 W m-2 for Rn, LE, H and G, respectively. The METRIC and STSEB models are very similar when it comes to providing information on water needs of the sorghum.
实际地表蒸散量的估算有助于作物需水量的量化。近年来已证明具有很大价值的利用渗湿计来准确估计水需求的另一种办法是利用遥感与基于地表能量平衡的模式相结合的方法。模型种类繁多，可分为两类:一类是单源模型，如采用内化校准(METRIC)算法的高分辨率蒸散发映射(Mapping EvapoTranspiration)模型;另一类是双源模型，如简化双源能量平衡(STSEB)模型。本研究的目的是分析如何使用METRIC和STSEB与蒸渗仪数据进行比较，以估计巴西RN Apodi高粱作物不同发育阶段的ET。两种模型在试验半干旱条件下的日ET估算精度，通过METRIC和STSEB分别具有0.8和0.7 mm d-1的RMSE值，被认为可以接受灌溉管理目的。在瞬时尺度下，METRIC对Rn、LE、H和G的误差分别为60、50、130和5 W m-2，而STSEB对Rn、LE、H和G的误差分别为40、70、120和21 W m-2。在提供高粱需水量信息方面，METRIC模型和STSEB模型非常相似。
{"title":"Evapotranspiration of sorghum from the energy balance by METRIC and STSEB","authors":"João G. A. Lima, J. M. Sánchez, J. Piqueras, José Espínola Sobrinho, Paula C. Viana, Aline da S. Alves","doi":"10.1590/1807-1929/agriambi.v24n1p24-30","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n1p24-30","url":null,"abstract":"The estimate of the actual surface evapotranspiration (ET) contributes to quantifying the water needs of crops. An alternative to the use of lysimeter for an accurate estimation of water needs, which has proved to be of great value in recent years, is the use of remote sensing combined with models based on surface energy balance. There is wide variety of models that can be classified into two types: one-source models, such as the Mapping EvapoTranspiration at high Resolution with Internalized Calibration (METRIC) algorithm, or two-source models, such as the Simplified Two-Source Energy Balance (STSEB). The objective of this study was to analyze how METRIC and STSEB can be used to estimate ET, in comparison with the lysimeter data, for the different stages of development of the sorghum crop in Apodi, RN, Brazil. The accuracy of both models in the daily ET estimation for the semi-arid conditions of the experiment, with RMSE values of 0.8 and of 0.7 mm d-1 through METRIC and STSEB, respectively, is considered acceptable for irrigation management purposes. The errors obtained with METRIC at an instantaneous scale were 60, 50, 130 and 5 W m-2 for Rn, LE, H and G, respectively, on the other hand, using STSEB these errors were of 40, 70, 120 and 21 W m-2 for Rn, LE, H and G, respectively. The METRIC and STSEB models are very similar when it comes to providing information on water needs of the sorghum.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"94 1","pages":"24-30"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80611873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p379-384
N. S. Henrique, K. L. Maltoni, G. A. Faria
ABSTRACT The form of occupation of the state of Rondônia, Brazil, favored the extensive agriculture, which resulted in a fast deforestation. The removal of forests and inadequate soil management and use, combined with a hot and wet climate, affected the soil chemical, physical, and biological attributes. In search for less impacting and alternatives that promote greater soil conservation for coffee production in the North region of Brazil, the objective of this work was to evaluate the effects of two coffee crop systems on the soil chemical and microbiological attributes. The treatments consisted of a shaded coffee crop (SCC) and a full-sun coffee crop (FCC). A completely randomized design was used, with four clusters per treatment and seven sampling points per cluster, which constituted a replication, totaling 28 replications per treatment. The data were collected in April 2018, in a rural property in the municipality of Cacoal, state of Rondônia, Brazil (11º21’50’’S, 61º20’10’’W, and altitude of 238 m). The soil organic matter, pH, P, K, Ca, Mg, Al, H+Al, base saturation, and basal respiration were determined. The soil under SCC had higher Ca content, pH, and base saturation, and lower potential acidity (H+Al) and Al content than that under FCC. The litterfall on the soil under FCC presented higher N and Mg contents. The soil basal respiration increased in the first 5 cm depth in the treatment with SCC.
{"title":"Soil quality in two coffee crop systems in the Amazon biome","authors":"N. S. Henrique, K. L. Maltoni, G. A. Faria","doi":"10.1590/1807-1929/agriambi.v24n6p379-384","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n6p379-384","url":null,"abstract":"ABSTRACT The form of occupation of the state of Rondônia, Brazil, favored the extensive agriculture, which resulted in a fast deforestation. The removal of forests and inadequate soil management and use, combined with a hot and wet climate, affected the soil chemical, physical, and biological attributes. In search for less impacting and alternatives that promote greater soil conservation for coffee production in the North region of Brazil, the objective of this work was to evaluate the effects of two coffee crop systems on the soil chemical and microbiological attributes. The treatments consisted of a shaded coffee crop (SCC) and a full-sun coffee crop (FCC). A completely randomized design was used, with four clusters per treatment and seven sampling points per cluster, which constituted a replication, totaling 28 replications per treatment. The data were collected in April 2018, in a rural property in the municipality of Cacoal, state of Rondônia, Brazil (11º21’50’’S, 61º20’10’’W, and altitude of 238 m). The soil organic matter, pH, P, K, Ca, Mg, Al, H+Al, base saturation, and basal respiration were determined. The soil under SCC had higher Ca content, pH, and base saturation, and lower potential acidity (H+Al) and Al content than that under FCC. The litterfall on the soil under FCC presented higher N and Mg contents. The soil basal respiration increased in the first 5 cm depth in the treatment with SCC.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"29 1","pages":"379-384"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90626817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p394-401
H. S. M. Vale, D. O. Costa, R. O. Batista, F. A. Oliveira, J. F. Medeiros, D. Coelho
ABSTRACT The objective of this study was to evaluate the uniformity of distribution in drip units applying dilutions of treated water produced by oil exploration. The experiment was set up in a completely randomized design in a split-split-plot scheme, with three replicates. The plots were composed of the treatments P0 - 100% groundwater, control; P10 - 90% groundwater and 10% produced water; P20 - 80% groundwater and 20% produced water; P30 - 70% groundwater and 30% produced water; and P40 - 60% groundwater and 40% produced water; the subplots had the types of non-pressure compensating drippers (D1 - 1.6 L h-1, Netafim Super Typhoon, D2 - 1.6 L h-1, Netafim Streamline and D3 - 1.7 L h-1, NaanDanJain TalDrip); and the sub-subplots contained the evaluation times (0, 40, 80, 120 and 160 h). Distribution uniformity and statistical uniformity coefficients were evaluated every 40 h, until completing 160 h. The pH of the dilutions was the attribute posing the highest risk of clogging to the emitters. Also in relation to dilutions, P40 caused greater application non-uniformity in D2, while the highest values of application uniformity were achieved in treatments P10 and P20 with D1 and D3, indicating the effectiveness of dilution in minimizing clogging.
摘要:本研究的目的是利用石油勘探产出的处理水的稀释剂来评价滴灌装置中分布的均匀性。试验采用完全随机设计，分-分-图设计，设3个重复。样地由P0 ~ 100%地下水处理组成，对照;P10 - 90%地下水和10%采出水;P20 - 80%地下水和20%采出水;P30 - 70%地下水和30%采出水;P40—60%地下水和40%采出水;子图为无压力补偿型滴流器(D1 ~ 1.6 L h-1, Netafim Super Typhoon, D2 ~ 1.6 L h-1, Netafim Streamline, D3 ~ 1.7 L h-1, NaanDanJain TalDrip);每隔40 h评估一次分布均匀性和统计均匀性系数，直至完成160 h。稀释液的pH值是对排放者造成堵塞风险最高的属性。同样与稀释相比，P40在D2中造成了更大的施用不均匀性，而D1和D3在P10和P20处理中达到了最高的施用均匀性，表明稀释在减少堵塞方面的有效性。
{"title":"Distribution uniformity in drip units applying dilutions of treated water produced by oil exploration","authors":"H. S. M. Vale, D. O. Costa, R. O. Batista, F. A. Oliveira, J. F. Medeiros, D. Coelho","doi":"10.1590/1807-1929/agriambi.v24n6p394-401","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n6p394-401","url":null,"abstract":"ABSTRACT The objective of this study was to evaluate the uniformity of distribution in drip units applying dilutions of treated water produced by oil exploration. The experiment was set up in a completely randomized design in a split-split-plot scheme, with three replicates. The plots were composed of the treatments P0 - 100% groundwater, control; P10 - 90% groundwater and 10% produced water; P20 - 80% groundwater and 20% produced water; P30 - 70% groundwater and 30% produced water; and P40 - 60% groundwater and 40% produced water; the subplots had the types of non-pressure compensating drippers (D1 - 1.6 L h-1, Netafim Super Typhoon, D2 - 1.6 L h-1, Netafim Streamline and D3 - 1.7 L h-1, NaanDanJain TalDrip); and the sub-subplots contained the evaluation times (0, 40, 80, 120 and 160 h). Distribution uniformity and statistical uniformity coefficients were evaluated every 40 h, until completing 160 h. The pH of the dilutions was the attribute posing the highest risk of clogging to the emitters. Also in relation to dilutions, P40 caused greater application non-uniformity in D2, while the highest values of application uniformity were achieved in treatments P10 and P20 with D1 and D3, indicating the effectiveness of dilution in minimizing clogging.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"28 1","pages":"394-401"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87778236","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p364-371
S. M. D. Menezes, G. F. Silva, Valentin Ruben Orcan Zamora, M. M. D. Silva, A. Silva, Ê. F. D. F. Silva
ABSTRACT The objective of this study was to evaluate the nutritional status of coriander cultivar Verdão under fertigation depths and pulse and continuous drip irrigation. The experiment was conducted in a protected environment at the Universidade Federal Rural de Pernambuco, Recife, PE, Brazil (8° 1’ 6.50” S, 34° 56’ 46” W and altitude of 6.5 m), in the randomized block design in 2 x 5 factorial scheme, with three repetitions. Treatments consisted of five irrigation depths (40, 60, 80, 100 and 120% of crop evapotranspiration - ETc) and two types of fertigation application (pulse and continuous). At 27 days after sowing, the aerial part of 48 plants per plot was collected for subsequent quantification of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper and zinc concentrations. Pulse fertigation combined with ETc replacement depths below 100% promoted higher leaf concentrations of phosphorus, sulfur, iron and manganese. Continuous fertigation combined with 100% ETc depth induced sulfur deficiency in the crop and, combined with 40% ETc depth, promoted the highest calcium concentration. Regardless of the type of application, ETc replacement depths from 82.7 and 40% provide adequate leaf concentrations of nitrogen and magnesium, respectively. Regardless of the applied depth, pulse fertigation reduced the leaf concentrations of magnesium.
{"title":"Nutritional status of coriander under fertigation depths and pulse and continuous drip irrigation","authors":"S. M. D. Menezes, G. F. Silva, Valentin Ruben Orcan Zamora, M. M. D. Silva, A. Silva, Ê. F. D. F. Silva","doi":"10.1590/1807-1929/agriambi.v24n6p364-371","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n6p364-371","url":null,"abstract":"ABSTRACT The objective of this study was to evaluate the nutritional status of coriander cultivar Verdão under fertigation depths and pulse and continuous drip irrigation. The experiment was conducted in a protected environment at the Universidade Federal Rural de Pernambuco, Recife, PE, Brazil (8° 1’ 6.50” S, 34° 56’ 46” W and altitude of 6.5 m), in the randomized block design in 2 x 5 factorial scheme, with three repetitions. Treatments consisted of five irrigation depths (40, 60, 80, 100 and 120% of crop evapotranspiration - ETc) and two types of fertigation application (pulse and continuous). At 27 days after sowing, the aerial part of 48 plants per plot was collected for subsequent quantification of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper and zinc concentrations. Pulse fertigation combined with ETc replacement depths below 100% promoted higher leaf concentrations of phosphorus, sulfur, iron and manganese. Continuous fertigation combined with 100% ETc depth induced sulfur deficiency in the crop and, combined with 40% ETc depth, promoted the highest calcium concentration. Regardless of the type of application, ETc replacement depths from 82.7 and 40% provide adequate leaf concentrations of nitrogen and magnesium, respectively. Regardless of the applied depth, pulse fertigation reduced the leaf concentrations of magnesium.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"1 1","pages":"364-371"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79556801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p357-363
E. D. Bocuti, R. Amorim, L. A. D. L. D. Raimo, W. A. Magalhães, E. C. D. Azevedo
ABSTRACT The objective of this study was to determine the effective hydraulic conductivity of six areas located in the Cerrado region of Mato Grosso, Brazil, and to identify physical attributes of soils with potential for predicting effective hydraulic conductivity. The tests to determine the effective hydraulic conductivity were carried out in six areas, covering the textural classes sand, sandy loam and clay, and the following uses: pasture, Cerrado and agriculture. Particle size, sand fractionation, total carbon content, degree of clay flocculation, bulk density, macroporosity, microporosity, mean weight diameter, mean geometric diameter and aggregate stability index were determined. From the data, statistical analyses of contrasts were performed by the Kruskal - Wallis test, and simple Pearson’s correlation coefficient was determined between variables. The average values of effective hydraulic conductivity for the pasture, agriculture and Cerrado areas were 95.73, 27.83 and 48.31 mm h-1, respectively. Higher value of effective hydraulic conductivity was observed in the Pasture area point 2 when compared to the Agriculture area point 2, because the amount of clay determined in Agriculture area was approximately 16 times greater than that of the area Pasture point 2, conditioning lower water infiltration in the soil profile of the area Agriculture point 2. Among the physical attributes analyzed, those with the highest potential for Ke prediction were: clay, silt, sand (coarse, medium and fine), total carbon and aggregate stability index.
本研究的目的是确定位于巴西马托格罗索州塞拉多地区六个地区的有效水力导率，并确定具有预测有效水力导率潜力的土壤物理属性。确定有效水力导电性的测试在六个区域进行，包括砂、砂壤土和粘土的质地类别，以及以下用途:牧场、塞拉多和农业。测定了粒径、砂粒分馏、总碳含量、粘土絮凝度、容重、宏观孔隙率、微观孔隙率、平均重径、平均几何径和骨料稳定性指数。根据数据，采用Kruskal - Wallis检验进行对比统计分析，并确定变量间的简单Pearson相关系数。牧区、农业区和塞拉多区有效导水率平均值分别为95.73、27.83和48.31 mm h-1。放牧区2点的有效导水率高于农业区2点，因为农业区测定的粘土量约为放牧区2点的16倍，从而调节了农业区2土壤剖面的低入渗。在分析的物性属性中，对Ke预测潜力最大的物性属性为:粘土、粉砂、砂(粗、中、细)、总碳和团聚体稳定指数。
{"title":"Effective hydraulic conductivity and its relationship with the other attributes of Cerrado soils","authors":"E. D. Bocuti, R. Amorim, L. A. D. L. D. Raimo, W. A. Magalhães, E. C. D. Azevedo","doi":"10.1590/1807-1929/agriambi.v24n6p357-363","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n6p357-363","url":null,"abstract":"ABSTRACT The objective of this study was to determine the effective hydraulic conductivity of six areas located in the Cerrado region of Mato Grosso, Brazil, and to identify physical attributes of soils with potential for predicting effective hydraulic conductivity. The tests to determine the effective hydraulic conductivity were carried out in six areas, covering the textural classes sand, sandy loam and clay, and the following uses: pasture, Cerrado and agriculture. Particle size, sand fractionation, total carbon content, degree of clay flocculation, bulk density, macroporosity, microporosity, mean weight diameter, mean geometric diameter and aggregate stability index were determined. From the data, statistical analyses of contrasts were performed by the Kruskal - Wallis test, and simple Pearson’s correlation coefficient was determined between variables. The average values of effective hydraulic conductivity for the pasture, agriculture and Cerrado areas were 95.73, 27.83 and 48.31 mm h-1, respectively. Higher value of effective hydraulic conductivity was observed in the Pasture area point 2 when compared to the Agriculture area point 2, because the amount of clay determined in Agriculture area was approximately 16 times greater than that of the area Pasture point 2, conditioning lower water infiltration in the soil profile of the area Agriculture point 2. Among the physical attributes analyzed, those with the highest potential for Ke prediction were: clay, silt, sand (coarse, medium and fine), total carbon and aggregate stability index.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"11 1","pages":"357-363"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88612925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-01DOI: 10.1590/1807-1929/agriambi.v24n6p422-427
José Neuman de Souza, L. D. A. Monteiro, V. C. D. Santos, M. Silva, Isabela O. Lima, W. M. Silveira
ABSTRACT During the working day, agricultural machinery operators are often exposed to physical risks, such as vibration, which can compromise their health and performance. Micro tractors emit high levels of vibration, which mainly affect their hands and arms. Thus, this study aims at evaluating the efficiency of different glove models in reducing vibration transmitted by the micro tractor/rotary tiller assembly according to the operating velocity and the rotation of the rotary tiller rotor. A completely randomized block design was used in a 4 x 2 x 2 factorial arrangement with five replicates. The study analyzed three glove models (G1 and G2 anti-vibration models, and anti-impact model G3) and a control treatment under the same operating conditions, but without the use of protective equipment. The study was conducted at two operating velocities (V1 = 0.98 km h-1 and V2 = 1.6 km h-1) and two rotations of the rotary tiller rotor (R1 = 265 rpm and R2 = 520 rpm). None of the evaluated glove models reached the attenuation capacity required by the Occupational Hygiene Standard (Norma de Higiene Ocupacional - NHO 10) and, under some operating conditions, they raised the incident vibration levels, exceeding the values obtained when the work was performed without a protective equipment. Although the anti-impact model G3 and the anti-vibration model G2 did not reduce the transmitted vibration to the levels considered acceptable by NHO 10, the anti-impact G3 and anti-vibration G2 models showed better performance in the work performed at a velocity of 0.98 km h-1 and a rotation of 520 rpm of the rotary tiller rotor.
在工作中，农机操作人员经常面临振动等物理风险，这些风险会损害他们的健康和工作效率。微型拖拉机发出强烈的振动，主要影响他们的手和手臂。因此，本研究旨在根据旋耕机转子的运行速度和转动情况，评估不同手套型号对微拖拉机/旋耕机总成传递振动的降低效率。采用完全随机区组设计，采用4 × 2 × 2因子排列，共5个重复。本研究分析了三种手套模型(G1和G2抗振动模型，G3抗冲击模型)和相同操作条件下的对照处理，但不使用防护设备。研究采用两种操作速度(V1 = 0.98 km h-1, V2 = 1.6 km h-1)和旋耕机转子两种转速(R1 = 265 rpm, R2 = 520 rpm)。所评估的手套模型均未达到职业卫生标准(职业卫生规范- NHO 10)所要求的衰减能力，并且在某些操作条件下，它们提高了事故振动水平，超过了在没有防护设备的情况下进行工作时获得的值。虽然抗冲击模型G3和抗振动模型G2没有将传递振动降低到NHO 10可接受的水平，但抗冲击模型G3和抗振动模型G2在旋耕机旋翼转速为520rpm、转速为0.98 km h-1时的工作表现较好。
{"title":"Efficiency of anti-vibration gloves in soil preparation using a micro tractor","authors":"José Neuman de Souza, L. D. A. Monteiro, V. C. D. Santos, M. Silva, Isabela O. Lima, W. M. Silveira","doi":"10.1590/1807-1929/agriambi.v24n6p422-427","DOIUrl":"https://doi.org/10.1590/1807-1929/agriambi.v24n6p422-427","url":null,"abstract":"ABSTRACT During the working day, agricultural machinery operators are often exposed to physical risks, such as vibration, which can compromise their health and performance. Micro tractors emit high levels of vibration, which mainly affect their hands and arms. Thus, this study aims at evaluating the efficiency of different glove models in reducing vibration transmitted by the micro tractor/rotary tiller assembly according to the operating velocity and the rotation of the rotary tiller rotor. A completely randomized block design was used in a 4 x 2 x 2 factorial arrangement with five replicates. The study analyzed three glove models (G1 and G2 anti-vibration models, and anti-impact model G3) and a control treatment under the same operating conditions, but without the use of protective equipment. The study was conducted at two operating velocities (V1 = 0.98 km h-1 and V2 = 1.6 km h-1) and two rotations of the rotary tiller rotor (R1 = 265 rpm and R2 = 520 rpm). None of the evaluated glove models reached the attenuation capacity required by the Occupational Hygiene Standard (Norma de Higiene Ocupacional - NHO 10) and, under some operating conditions, they raised the incident vibration levels, exceeding the values obtained when the work was performed without a protective equipment. Although the anti-impact model G3 and the anti-vibration model G2 did not reduce the transmitted vibration to the levels considered acceptable by NHO 10, the anti-impact G3 and anti-vibration G2 models showed better performance in the work performed at a velocity of 0.98 km h-1 and a rotation of 520 rpm of the rotary tiller rotor.","PeriodicalId":51288,"journal":{"name":"Revista Brasileira de Engenharia Agricola e Ambiental","volume":"62 1","pages":"422-427"},"PeriodicalIF":1.2,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84026619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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