Workable Days Research Articles

Number of workable days as a function of the water balance for planning mechanized sugarcane operations

Number of workable days as a function of the water balance for planning mechanized sugarcane operations

Evaluation of Agricultural Machinery Presence and Usage Activities in Tokat

In this study, the area of influence of agricultural machinery in Tokat, its districts and the size of the cultivated area were compared. Required number of machineries was evaluated. Thus, the machines were divided into seven groups (Soil Tillage Machinery, Sowing and Planting Machinery, Maintenance and Fertilization Machinery, Plant Protection Machinery, Harvesting Machinery, Combine Harvester, Tractors). Data on the number of cultivated areas and agricultural machinery were taken from the Turkish Statistical Institute. The number of machines, daily working time, annual workable days, effective working capacity, and machine impact area for each machine were calculated separately. Based on this data, the number of machines that should be in each district was determined. As a result, it was determined that the number of Subsoiler, Combi Harrow, Stone Collecting Machinery, Rotary Cultivator, Soil levelling Machinery, Rotary Tiller, Seedling Planting Machinery, Arc Opening Plough, Manure Spreading Machinery, Baler, and Combine Harvester is insufficient in the province of Tokat. It was determined that other machines in the groups were more than necessary. Baler had the highest deficit, while tractor had the highest surplus. The importance of planning in enterprises and the machines that should be prioritized in the production of industrialists have been revealed.

Modeling days suitable for fieldwork using machine learning, process-based, and rule-based models

ContextPrediction of days suitable for fieldwork is important for understanding the potential effects of climate change and for selecting machinery systems to improve efficiency in field operations and avoid soil damage. Yet, we lack predictive models to inform decision-making at scale. ObjectiveWe filled this knowledge gap by developing and testing five new workability models. MethodsOne model follows soil moisture-based methods (APSIM), one uses simple rain and temperature thresholds, and three follow machine learning techniques (Random Forest, Decision Table, Neural Network). We parameterized the models using USDA survey data from Iowa, USA and evaluated their temporal and spatial prediction over twelve US Corn Belt States and different time periods using multiple statistical indexes and sensitivity analysis. The models operate at a 5-arcminute resolution. Results and conclusionsResults indicated that the simple rule model, the Decision Table model, and the process-based model predicted field workable days with an agreement index of 0.88, 0.86, and 0.84, respectively for the testing datasets (n = 22,671), and hence were deemed sufficient for future use. The selected models are better suited for large timespan evaluations of workability (monthly to annual, normalized root mean square error, nRMSE = 8 to 15%)) than weekly predictions (nRMSE = 21%). The machine learning models tended to cluster their predictions around a mean value and were about 50% less responsive to precipitation than the process-based or rule-based models. We concluded that simple approaches are more robust to be applied at scale than complex approaches with many data input requirements. SignificanceThe developed models enhance our capacity to predict climate change impacts on workability, a valuable indicator for decision-making and overall sustainability.

Development of a Pilot Soil-Water Balance Model for Determination of Probability of a Working Day for Rice Harvesting

Abstract The probability of a working day is the ratio of workable days to the total available days in a working season for the intended operation. Soil moisture is the most important limiting factor in terms of rice harvesting. Therefore, to determine the PWD for this operation, a model was developed to estimate the soil moisture based on soil-water balance. To calibrate and validate the model, the soil moisture was monitored in the paddy field of the University of Guilan during the rice harvest seasons in 2017 and 2018. The calibration process was performed by applying a decreasing ratio, i.e. the senescence factor (α), at a daily evapotranspiration rate compared to that of previous day. At the validation stage, the simulated soil moisture contents were compared with measured values, which indicated a good model accuracy (NRMSE = 6.53%) of the soil moisture estimation. Therefore, this model can be used for the rice harvesting operation feasibility evaluation and PWD calculation.

Modelo computacional de predição de dias trabalháveis para semeadura da soja em municípios de Mato Grosso

Atualmente, na agricultura, a grande competitividade exige que os agricultores elaborem estratégias para maximizar lucros e aumentar a eficiência produtiva. Assim, é fundamental no planejamento que o produtor estime o tempo disponível para realizar suas operações levando em consideração, como fator principal, as variáveis climáticas. Neste trabalho, analisou-se as probabilidades de ocorrência de dias trabalháveis e o número de conjuntos mecanizados necessários para operações de semeadura da soja nos municípios de Diamantino e Sinop do estado do Mato Grosso. Para isso obteve-se dados meteorológicos dos referidos municípios e identificou-se os dias favoráveis a semeadura através dos critérios de precipitação < 5 mm e o armazenamento de água no solo (ARM) entre 40 e 90% da capacidade de água disponível (CAD). Simulou-se o número de dias trabalháveis através de três diferentes critérios, sendo de 40%, 50% e 60% do dia ser favorável a semeadura, em seguida estimou-se o número de conjuntos mecanizados necessários para semeadura em uma determinada área. Para ambos os municípios, os valores da probabilidade do dia ser favorável a semeadura P(F) aumentaram após o início das chuvas. Já a demanda de maquinários variou conforme o critério adotado sendo menor quando se considerou o critério de 40% de P(F).

Mapping soil organic carbon and clay using remote sensing to predict soil workability for enhanced climate change adaptation

Climate change is presenting sizeable challenges for agricultural production around the world. In some regions, shifting precipitation patterns in the spring and fall are negatively impacting farm operation by reducing the number of “workable days” or the days fields can be worked with heavy equipment without damaging soil structure. This can be particularly problematic for farms on clay soils and/or poor drainage. Approximating a water content threshold at which a soil is not workable due to soil structure destruction can be helpful for planning effective farm operations. In this study, we applied advanced remote sensing and machine learning tools to produce digital maps of soil organic carbon (SOC) and clay (CL) content and used them in existing pedotransfer functions (PTFs) to predict a workability threshold (WT) across a study area in Delta, British Columbia, Canada. We combined field data, soil and vegetation indices derived from multiple Landsat satellite images, topographic indices, and soil survey information to digitally map SOC and CL of the agricultural lands in Delta using random forest (RF) and generalized boosted regression model (GBM). When validated against an independent field dataset, the RF model outperformed GBM for all accuracy measures (coefficient of determination – R2, concordance correlation coefficient – CCC, and normalized root mean square error – nRMSE). We then spatially applied several PTFs using our digital maps to estimate the plasticity limits of the soil and produce WT map. The WT map was then tested against independent field samples of the soil water content at −10 kPa and we achieved R2 of 0.59, CCC of 0.70, and nRMSE of 0.15. Our analysis showed that 40% of the fields in the study area had WT < 30%, a threshold that is already being impacted by reduced workable days. This WT map could be used to improve spatial prioritizations of investmentsfor climatechangeadaptation at farm to regional scales.

Investigation of The Workable Days in Agriculture Using Meteorological Parameters

In this study, it was aimed to determine the workable days in agriculture using meteorological parameters, and a databank was formed obtaining the inputs from all weather stations in Central Anatolia Region, which cover a 20-year period, from 1986 to 2006. Running a mathematical model in a computer software specifically designed for this purpose, the data of this databank were exploited to calculate the workable days on a land for soil treatment, crop care and harvest for any given region and to show these data with graphs on monthly or yearly basis. This software may help to use time more economically and reduce the system costs directly or indirectly. Moreover, the data collected are quite necessary to prepare some national or local charts and graphs related to the general distribution of various climate factors.

Soil water contents for tillage: A comparison of approaches and consequences for the number of workable days

We propose the soil strength and air capacity (SSAC) approach, which was compared with alternative water retention curve (WRC) and the soil consistency (SC) approaches for estimating the water content at wet tillage limit (θWTL), optimum water content for tillage (θOPT) and the water content at the dry tillage limit (θDTL). Unlike the WRC and SC approaches, the SSAC approach uses a fixed value of air-filled porosity and tensile strength of soil aggregates to determine the wet and dry tillage limits: θWTL is estimated as soil water content at an air-filled porosity of 0.10 m3 m–3, and θDTL as soil water content at tensile strength of 50 kPa. The θOPT is estimated using the double-exponential model as soil water content at the local minimum of the pore size distribution between the peaks of the textural and structural pores. The three approaches were compared using soils from the Highfield long-term field experiment (UK) with a range of soil organic carbon (SOC, 0.009–0.033 kg kg–1), and soil from Lerbjerg (DK) with a range of clay contents (0.12–0.45 kg kg–1). Workable days for the soils in spring and autumn between 2014 and 2018 was estimated using a decision support tool for assessing soil workability. Workability was limited where soil conditions were either too wet (>θWTL) or too dry (<θDTL). For both Highfield and Lerbjerg soils, θWTL for the SC approach was generally drier than that for WRC and SSAC approaches. The number of workable days per season were influenced by SOC and clay contents. Soil with higher SOC had average of 36 and 23 workable days in the spring and the autumn, respectively, more than soil with low SOC. The number of workable days per season decreased with increasing clay content. Soil with lower clay had average of 21 and 25 workable days in the spring and the autumn, respectively, more than soil with high clay. The approach used for estimating θWTL and θDTL has impact on the number of workable days. For both soils studied, the number of workable days per season were more for WRC and SSAC approaches compared to the SC approach. While we believe the SSAC approach to be based on sound physical principles, further studies are needed to test the practical application of the SSAC approach for estimating θWTL, θDTL and workable days on more soils.

Sequence of Workable Days for Mechanized Harvest of Sugarcane in Southern Brazil

The probabilities of workable days (WD), as well as probability of having a given sequence of days for sugarcane mechanized harvest in Southern Brazil is a very useful information for planning of such operation. Thus, the aim of this study was to determine the simple and conditional probabilities of WD for the abovementioned field operation in the State of S&amp;atilde;o Paulo, Brazil, by means of the Markov Chain, to define the probabilities of sequences of WD. The number of WD (NWD) was determined for 32 years for ten sites using as criteria soil water holding capacity of 40 mm, rainfall &amp;le; 3 mm and relative soil water storage &amp;le; 90%. Based on NWD dataset, the simple probabilities of WD and non-workable (NW) days, as well as the conditional probabilities were determined. Finally, the probability of sequences of WD per ten-day period was obtained by the Markov chain. The results showed that Western, Northwestern and Northern, on average, were more likely to have WD compared to Southern and Eastern regions of the state. In addition, the most likely periods of WD were between April and September, being the first ten-day period of July the one with the highest possible probability (&amp;ge; 90%). The probability of having a workable day given that the previous day was workable always remained at a minimum of roughly 50% along with a maximum close to 90% at all assessed sites. Finally, the probability of a sequence of eight or more WD per ten-day period was always below 40% along the year, showing that is difficult to have such a long period available for planning sugarcane mechanized harvest in the assessed locations. Therefore, we recommend that fleets sizing should be defined as a function of NWD in conjunction with the probability of the sequence of WD at a given ten-day period.

Agrometeorological and Soil Criteria for Defining Workable Days for Rational Mechanized Sugarcane Harvest in Southern Brazil

The number workable days (NWD) for agricultural field operations is of great importance for sizing agricultural machinery fleets. This is especially pivotal for sugarcane harvest, which extends from 8 to 10 months/year. In light of this, the current study aimed at defining criteria for obtaining the NWD for rational sugarcane harvest at different sites in the state of São Paulo, southern Brazil, taking into account both a general and a specific criteria. For this purpose, data from harvest interruption of 30 sugar mills in southern Brazil throughout periods ranging from two to five years were used. The following variables were tested as criteria for defining harvest interruption: minimum precipitation (PREC); soil water holding capacity (SWHC); and the limit of the ratio between actual soil moisture (SM) and SWHC. Based on such a specific criterion ascribed to each site along with a general criterion, NWD maps were prepared for the state of São Paulo, Brazil. The results showed that there were variations from the definition criteria of NWD at the different sites in the state. However, the use of a general criterion for harvest interruption, based on PREC ≥ 3 mm, SWHC = 40 mm and SM/SWHC ≥ 90%, provided accurate results. During the validation of these criteria, the NWD maps generated from the individual criterion proposed for each site resulted in an average error of 24.9 days/year, whereas the map generated from the general criterion culminated in an average error of 4.4 days/year.

Subsurface drainage for promoting soil strength for field operations in southern Manitoba

Successful field operations depend on the ability of the soil to provide traction and support for agricultural traffic and be workable in a desirable manner. This minimizes the risk of soil structural damage to ensure soil conservation and long-term crop yield. In the present study, the objective was to evaluate the performance of subsurface drainage in promoting soil strength for field operations in southern Manitoba. Data obtained from a field study and modeling exercise were used to achieve the objective. The field data include soil water content and watertable depth, which were measured in a potato field during the 2011 growing season. Soil samples were also collected from the field to determine the lower plastic limit (LPL) of the soil. Seventeen-year weather data were used to estimate the reference crop evapotranspiration. The soil strength of drained and undrained sandy-loam fields was compared to evaluate subsurface drainage in promoting soil strength for field operations. The subsurface tile drain was installed at 0.9-m depth and at 15-m spacing. A validated HYDRUS (2D/3D) model was used to extend the study by simulating soil water content dynamics due to different drain spacings (8 m, 10 m, 12 m, 15 m, 20 m, and 30 m) for different years and weather conditions. The soil strength to allow field operations was assessed based on soil water content corresponding to 90% of the LPL in the top 0.3-m depth of the soil, and soil water content corresponding to the LPL in the soil layer between 0.3-m to 0.5-m depth of the soil profile. The soil strength was sufficient to allow field operations when the two criteria were met. In the top 0.3-m depth, the soil strength was sufficient to allow field operations for all the years with or without drainage. Drainage impact was found to be more significant within the 0.3-m to 0.5-m depth of the soil profile throughout the years. Drain spacing less or equal to 12 m promoted soil strength to allow field operations without any significant impact on the number of field workable days during the growing season.

El sistema de transporte público en el cantón Ambato. Frecuencias, productividad y velocidad

En esta investigación se determina el promedio de tres variables: frecuencia de rutas, productividad y velocidad de viaje en el sistema de transporte público del cantón Ambato. Se aplicó una ficha de observación a las 22 líneas autorizadas en la ciudad en un periodo de 10 días laborables en horas de la mañana y tarde. Los resultados evidencian que las frecuencias oscilan entre 7,5 y 9 minutos; las líneas 6, 20 y 21 registran mayor productividad mientras que las líneas 4, 8 y 12 tienen menor productividad, referente a la velocidad el promedio de las rutas investigadas es 18,93 km/h. Los datos obtenidos brindan una visión general del sistema de transporte público que contribuye a la toma de decisiones por parte de las instituciones involucradas. Palabras clave: Transporte público, frecuencias, calidad de servicio, productividad de transporte. URL: http://revistas.uta.edu.ec/erevista/index.php/bcoyu/article/view/629

Changes in field workability and drought risk from projected climate change drive spatially variable risks in Illinois cropping systems.

As weather patterns become more volatile and extreme, risks introduced by weather variability will become more critical to agricultural production. The availability of days suitable for field work is driven by soil temperature and moisture, both of which may be altered by climate change. We projected changes in Illinois season length, spring field workability, and summer drought risk under three different emissions scenarios (B1, A1B, and A2) down to the crop district scale. Across all scenarios, thermal time units increased in parallel with a longer frost-free season. An increase in late March and Early April field workability was consistent across scenarios, but a decline in overall April through May workable days was observed for many cases. In addition, summer drought metrics were projected to increase for most scenarios. These results highlight how the spatial and temporal variability in climate change may present unique challenges to mitigation and adaptation efforts.

Analyzing the sensitivity of viticultural practices to weather variability in a climate change perspective: an application to workable-day modelling

&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Aims&lt;/strong&gt;: The study aims at applying to a perennial crop the concept of “workable days” developed for annual crops by G. Kreher in 1955. A workable day is a day that provides conditions agronomically correct for work.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Methods and results&lt;/strong&gt;: A survey among grapevine growers was carried out to collect their perception of practice sensitivity to weather variability. The study provided information on working periods, techniques and machinery involved, weather constraints and thresholds generally used by the vine growers, for 21 annual cropping practices. Pesticide spraying against powdery and downy mildew appeared to be the most sensitive to weather parameters. Therefore, this practice was selected for the purpose of modelling workable days, according to decision rules based on the postulate that all weather parameters should be within the acceptable ranges. The model was run over a period of 13 years (1998-2010). Analyses of the outputs pointed out a great variability in the number of workable days from one year to another as well as in the respective proportion of unfavourable weather factors involved in the reduction of workable days. A validation based on the analysis of the actual spraying practices realized over a period of 12 years (1999-2010) showed that 32 % of the treatments were done on a day characterized as not workable by the model. The errors could be attributed to periods of holidays and risky sanitary situations when decision rules had to be bypassed.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Conclusion&lt;/strong&gt;: The model proved to represent rather well the decision rules use by vine growers to carry out their annual cropping practices in relation with the weather variability, within the area of study. The controversial role of the ‘leaf wetness duration’ weather parameter needs to be clarified; it may help to better parametrize the model. In order to improve its performance, the model should be coupled to a disease propagation model.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;&lt;strong&gt;Significance and impact of the study&lt;/strong&gt;: In a climate change perspective, modelling of workable days can be run with simulated climatic data. It may prove to be useful to adapt vineyard management strategies in terms of innovative cropping practices and equipment.&lt;/p&gt;

Trend of Workable Days of Agriculture Related with Precipitation in Northern Part of Iwate

Trend of Workable Days of Agriculture Related with Precipitation in Northern Part of Iwate

Estimation of Critical Limits by Marine work types for the Construction of Seawall at Sinseondae in Busan, Korea

Yoo, C.I., Roh, S.H., Ryu, C.R., 2013. Estimation of Critical Limits by Marine work types for the Construction of Seawall at Sinseondae in Busan, Korea In: Yoo, C.I., (eds.), Proceedings 12 th International Coastal Symposium (Plymouth, England), Journal of Coastal Research, Special Issue No. 65, pp. xxx-xxx, ISSN 0749-0208. Weather and wave climate is an important factor for the calculation of workable days and operation hours of equipment for the construction of seawall. However, at present, the number of working days calculated is based on the results of Ro (1969) which are more than 40 years old. In addition, in recent years, the work environment has changed a lot because of state-of-the-art construction equipment and extreme weather conditions due to global warming. Therefore, it is necessary to recalculate workable days to estimate critical limits of marine construction. The purpose of this study is to analyze the critical limits of work types for the construction of seawall using daily field work sheets and the meteorological conditions at Sinseondae in Busan, Korea. Also, the measurements of damaged seawall by high waves and one small typhoon were carried out, and days spent on disaster recovery were recorded. Finally, the working hours for each kind of construction equipment at each stage were collected, and the utilization rate of the major equipments was calculated. The results of estimated weather conditions for workable days and non-workable days between September, 2006 and November, 2008 monthly average 26.1 and 4.3 days, respectively (as shown in the worksheet below). Moreover, workable and non-workable days compared with Ro (1969) are estimated to increase 129.1% and decrease 42.2%, respectively. The result clearly shows that workable days have increased by about 30% over the past 40 years. The duration of damaged seawall with reconstruction totals 62 days out of 317 workable days in 2007. As a matter of fact, it is reasonable to suppose that the purely monthly average of workable days of seawall construction is 20.1 days.

Percentage of workable days in scheduling superstructure work for building construction projects in Korea

In scheduling building construction work, non-workable days due to weather conditions and national holidays lessen the accuracy of scheduling. This study aims to determine the percentage of workable days to enable more accurate scheduling of superstructure work in building construction. To calculate the percentage of workable days applicable to superstructure work in building construction, this study analyzed various data, including actual building cases. Actual weather data in the Seoul region for the past five years was used in particular and the number of national holidays therein was analyzed. This approach is intended to yield a more accurate and objective percentage of workable days. This study suggests that the use of yearly and monthly percentages of workable days in the scheduling for superstructure work of future building construction projects will make scheduling more objective and accurate.

Distribution of tractor available workdays over the southeastern Anatolia project (GAP) area

Determination of available workdays of a tractor for field operations is very significant in design, development, and selection of efficient machinery systems for agricultural operations. Available workdays vary and generally based on average daily temperature and amount of precipitation. In this study, an excel program was developed to determine the available workdays of a tractor in field operations. Available workdays of a tractor over the Southeastern Anatolia Project (Turkish: GuneydoAŸu Anadolu Projesi, GAP) region, opened for irrigation in 1995, were calculated with this software by using the meteorological data of the region. Results indicated significant changes in available workdays from east-to-west and north-to-south. Considering the 15 days period, maximum number of work days corresponds only 33% of the total period in April. Key words: Tractor, workable days, Southeastern Anatolia Project (GAP) area, spatial distribution.

Condições de drenagem relacionadas ao trânsito de máquinas em solo de várzea (RS-Brasil)

A exploração dos solos de várzeas do Rio Grande do Sul, Brasil, tem sido historicamente restrita ao binômio arroz irrigado-pecuária extensiva. Dentre os diversos fatores que contribuem para este quadro, as más condições de drenagem são dos mais restritivos, haja vista que, especificamente em relação ao arroz irrigado, tal situação acarreta atraso no plantio com conseqüente queda da produtividade. Como objetivo inicial, o modelo SWAP foi validado com dados de um solo típico das várzeas do Rio Grande do Sul, para posteriormente se empregá-lo na simulação de diversos cenários sob diferentes condições de drenagem e os resultados dessas simulações foram confrontados com critérios que avaliam a possibilidade de preparo do solo, com base em sua umidade. Este confronto mostrou haver relação muito estreita entre a drenagem subsuperficial e superficial; quando esta é satisfatória, os perfis de umidade podem ser compatíveis com o preparo do solo, mesmo com drenos subsuperficiais bastante espaçados; caso contrário, o crescimento no número de dias aptos para a mecanização exige a presença de drenos subsuperficiais muito próximos.

Transport metabolism, social diversity and equity: The case of São Paulo, Brazil

The movement of people in space implies the consumption of resources such as time, space, money and energy, as well as the production of negative externalities such as accidents, pollution and congestion. Some of these effects have been analyzed on an aggregate level by comparing regions in the world, a set of selected cities and different geographical areas in a particular city. The analysis of data on a more disaggregate level that considers the differences in the cause and continuance of negative transport externalities among social classes and groups living in a particular city in the developing world is rare. This paper uses the São Paulo Metropolitan Region (SPMR) 1997 origin–destination (OD) survey to investigate such phenomenon by taking advantage of the fact that data are divided according to six levels of household income. Results refer to mobility patterns in workable days. The main conclusions are that although people at the lowest income level spend a high share of their income on transport, they have a very low overall mobility and contribute almost nothing to transport externalities. At the other extreme, the two highest income groups that use cars intensively invest much more time, space and money to travel around and so contribute to transport externalities 8.4–15.2 times more than the lowest income group. Such large differences challenge current transport policies in developing countries and call both for a reassessment of assumptions and principles as well as for opposition to the propagation of myths that have sustained such inequitable policies.