ORIGINAL ARTICLE

Technological and Operational Evaluation of Agricultural Sets in Mechanized Labors in Tobacco Tillage

MSc. Emilio Ramírez-Castro^{I  *} 

Dr.C. Liudmyla Shkiliova^II 

^IUniversidad Técnica de Babahoyo UTB, Facultad de Ciencias Agropecuarias FACIAG, Babahoyo, Los Ríos, Ecuador.

^IIUniversidad Técnica de Manabí UTM, Facultad de Ingeniería Agrícola, Portoviejo, Manabí, Ecuador.

ABSTRACT

In this investigation, the technological and exploitation indexes of the Deutz Fahr Agrofarm 420-T Ecoline agricultural tractor sets and the implements (The Checchi Magli Unitrium transplanter, a three-body cultivator subsoiler and the Jacto Coral B12 sprinkler) were determined in Tabaganesha 2 tobacco farm, Los Rios Province, Valencia City, Ecuador. The methodology was based on the chronometric observation of the times in the work of transplantation, subsoiling and fumigation of tobacco. The following technological and exploitation indices were determined: times of clean work, of assistant work and of turning work, exploitation coefficients, technical security, use of productive time and others. For the development of the methodology the NC 34-37: 2003 standards were used; also tractor and implement testing and evaluation reports as well as technical documents and scientific articles. The results of the tractor indexes with the three evaluated implements showed the following values ​​reached in the coefficients of use of productive time (K04): The tractor-transplanter set obtained 0.77, the tractor-subsoiler set reached 0, 84 and the tractor-sprinkler set reached 0.47. The maximum value of 1.00 was obtained in the technological safety coefficients (K41) and technical safety coefficients (K42) for all the evaluated sets, because none of the sets suffered any damage during the evaluation period.

Keywords: Technological and Operational Indexes; Chronometric; Working Time; Turning Time; Operating Ratios

INTRODUCTION

Tobacco (Nicotiana tabacum L.) is a plant of tropical origin, but it is produced in latitudes as far apart as those corresponding to South Africa, Belgium, Canada or Brazil. Its cultivation area extends between 45 ° North latitude and 30 ° South latitude and the climate is one of the main determinants of the leaf qualities (^{Sánchez, 2019}).

It is a perennial crop, although under the cultivation condition it is considered annual, completing its cycle in an approximate period of 120 days, in which it germinates, develops and bears fruit. The root system is fibrous and branched, it is found in the first 30 cm below the soil surface, with an erect, cylindrical and herbaceous stem (^{Ramírez et. al., 2013}).

Tobacco is an agricultural species that is highly adaptable to a warm environment and has a singularly high reactive capacity to variations in the natural environment and in the technology applied in its production. (^{Ortéz, 2005}).

Traditionally, in tobacco cultivation, most of the cultural tasks such as seedlings, sowing in the field, hilling, weeding, fertilization, fumigation, and harvesting are carried out manually, with the use of day laborers, since many producers state that the agronomic management of the crop is more careful.

The basic cultural tasks of most crops use between 0.19 and 0.44 laborers per hectare; tobacco, on average, requires about 130 laborers / ha. Hence the enormous social implication that this activity presents in the areas where it is developed, since not even in other crops with intensive employment of the labor factor, this level of demand for it is reached. (^{Corradini et al., 2005})

This change in the technology of growing tobacco is due to the mere fact of trying to reduce the extensive amount of labor that can be used in different cultural tasks, and the agricultural mechanization has been seen as a relative way of lowering production costs, for the profitability of the crop. That is why the acquisition of agricultural machinery is seen more often in the cultivation of tobacco.

Two methods are used in transplantation, manual or mechanical, according to the degree of technology usage of the producer. The manual system is spread over 90% and mechanized, with the use of grapple or gravity cone transplanters, in the order of 10% (^{Corradini et al., 2005}).

^{Ramos (2018)} affirms that in Ecuador, the vast majority of tobacco planting is done manually with the hiring of day laborers. However, in Los Ríos Province, in Tabaganesha tobacco farm, since 2017, it has been decided to implement agricultural machinery for cultivation tasks in order to reduce the use of labor for traditional tasks such as sowing, hilling, weeding and fumigation.

The important exploitation indices depend essentially on the working conditions (^{Jróbostov, 1977}) and are determined from timing of the whole under observation, during the technological and exploitation evaluation, providing information of great utility for the producers (^{De Las Cuevas et al., 2008}; ^{Gaytán et al., 2005}; ^{Machado, 2015}).

At present, in many countries both, the preparation of the soils and the conduction of the plantation, are carried out mechanically, for the first case there are tractors of between 110 hp and 200 hp and for the provision of mechanical crops, the most common is to find 75 hp to 85 hp tractors (^{Corradini et al., 2005}).

The objective of this research is to present the results of the technological and exploitation evaluation of agricultural groups in mechanized tasks of transplantation, hilling and fumigation in tobacco cultivation.

MATERIALS AND METHODS

The present exploitative technological evaluation took place at the Hacienda Tabacalera Tabaganesha 2, Located at km 22 of Vial al Vergel, Canton Valencia, Los Ríos Province, Ecuador, with geographic coordinates 00 ° 50'42.5 ”S - 79 ° 24 '40, 6 ”W at an altitude of 80 meters above sea level with an average temperature of 24 ° C.^*

This hacienda has a land area of 320 hectares divided between 70 hectares destined for tobacco cultivation, and the remaining 250 hectares distributed in land without production, infrastructure and other crops. The type of soil that Tabaganesha SA has, based on the soil analysis and nematology report of ^{INIAP (2017)} is of the Franco Limoso Franco textural class, with low levels of organic matter 2.6% and an acid pH of 5, 0 with lime requirements. There is a low presence of nematodes throughout the property.

The objects of study of the experimentation are the sets formed by the Deutz Fahr Agrofarm 420T Ecoline tractor (100 hp or 75 kW) (Table 1) and the implements: Checchi Magli Unitrium transplanter, a three-body modified cultivator subsoiler and the Jacto Coral B12 sprinkler.

The farm's fleet of tractors and agricultural machinery is made up of four tractors of different powers and brands (John Deere 60 hp, SAME 85hp, Deutz Fahr Agrofarm 420-T Ecoline 100 hp tractor, and SAME 135 hp). It also has a Checchi Magli model Unitrium transplanter, a modified domestically made three-body subsoiler and a Jacto Coral model B12 sprinkler.

TABLE 1 Technical characteristics of the Deutz Fahr Agrofarm 420-T Ecoline tractor 

Motor
Model	SDF 1000.4 WTI EURO III
Cylinders / Displacement, nº / cm³	4/4000
Maximum power HP/kW	102 / 75
Gears / changes
Gears / changes	5
Ranges	2
Power Take Off - PTO
Clutch	Disc in oil bath with electro-hydraulic control
Spline Shaft	6/21
Engine Rev ratio /Rev. TDF 1000	2,286
Rear hydraulic lift
Rear lift	With mechanical control
Right brace and 3rd point	Mechanical
Lifting capacity, kg	4200

Source: (^{Deutz Fahr (2016)}

The Checchi Magli Unitrium Transplanter (Figure 1) with full control, semiautomatic, for conical and pyramidal clod plants up to 3 cm in diameter, driven by the Flex rubber drive wheel for wet and argillaceous soils in each transplanting unit, coupled to the whole system. It is suitable for seedlings with a particularly developed foliar apparatus (e.g. tobacco, tomato, cabbage, etc.). The transplant units are independent and modular. The rotary distributor with ten buckets guarantees high productivity and high comfort for the operator. The approximate production is 4 500 - 5 000 plants per hour each row. The version used for this research was of four bodies with a hydraulic folding chassis (TPI), the dimensions of this transplanter are: A) 200 cm wide and B) 350 cm long, and requires a minimum force of 40 hp (^{Checchi & Magli, 2012}).

Source: ^{Checchi & Magli (2012)} and ^{Ramírez & Shkiliova (2019)}.

FIGURE 1 Deutz Fahr Agrofarm 420-T Ecoline Tractor and Checchi & Magli Transplanter Set Unitrium.  

A 700 kg three-body modified domestic cultivator subsoiler, with a length of 2.17 m is coupled to the tractor through the integral system, minimum penetration required for cultivation 30 cm, maximum required penetration 70 cm, the bodies can be expanded or reduced according to the requirement of the culture format. It also has, in each of the bodies, a metallic lateral attachment that serves to hill and weed the crop as it can be seen in Figure 2. This means that the implement in question, in addition to subsoiling the land prior to transplanting, is given an additional use as a cultivator ^{Ramos (2018)}.

FIGURE 2 Three-body cultivator subsoiler of national manufacture. Source: ^{Ramos (2018)}. 

Jacto Coral B12 trailed sprayer, operates with a tubular chassis, in single shaft configurations (9.5 m × 24m wheels) or dipper (11Lx15). It has a 2 000-liter tank and manual bars of 16 m and 8 m on each side and greater economy during spraying (Table 2).

TABLE 2 Technical specifications of the Jacto Coral B12 sprayer 

TECHNICAL SPECIFICATIONS
length X width X height	3,80 m x 1,90 m x 3,60 m
Tires	7,5 x 16 (STD) 9,5 x 24 (Eje Cross)
Weight	660kg
TANK
Capacity Material Agitator	2000 L polyethylene mechanical
BOMB
Model Flow capacity Maximum working pressure	JP-75/100/150 75/100/150 L/min 300 psi
AGROCHEMICAL FILTER
Model Capacity mesh	FVS 100/200 100/ 200 L/min 60 / 24 / 40
BARS
Working width Drive	16 m Handbook
Working speed	up to 12 km / h
Maximum power consumption	5/6/8 cv

Source: ^{Jacto (2016)}

The following materials were used to measure the technological evaluation and exploitation times: digital stopwatch with a sensitivity of 1 s, Garmin ETREX SUMMIT HC Global Positioning System (GPS) with a margin of error of ± 3 m, tape measure with a minimum measurement of 1 cm and a maximum of 50 m, Samsung Health mobile application version 5.11.1.001 with a margin of error of ± 3 m to measure long distances.

The fuel consumed by the Deutz Fahr Agrofarm 420-T Ecoline tractor during the test and during the work shift was obtained through the control panel that it has, based on the fact that the agricultural technique has a capacity of 90 L or 24 gallons in the tank (^{DEUTZ FAHR, 2016}) and that measurement is reflected on the board by quarts (¼) of consumption tank, then represented in 6 gallons each quarter (¼). See fuel tank reference diagram (Figure 3).

FIGURE 3 Diagram of the fuel tank. 

The methodology was based on chronometric observation, that is, on the measurement and annotation of all the times of the operations carried out in the process of sowing, hilling, weeding and spraying in tobacco, as well as incidents during the set work. The following technological and exploitation indices were calculated in it: times of clean work, assistance, turning, of stops for various reasons, exploitation coefficients, technical security, use of productive time and others. For the elaboration of the methodology, test and evaluation reports for tractors and implements issued by the ^{Oficina Nacional de Normalización de Cuba (2003)} (National Office of Standards of Cuba) were used, as well as technical documents issued by the Instituto para la Diversificación y Ahorro de la Energía (^{IDAE, 2006a})(Institute for Diversification and Energy Saving).

During the comparative exploitation in the main type of work, no less than three control shifts were carried out, in each fund or representative condition and the duration of the working time was greater than 15 hours.

In each type of complementary work, no less than two control shifts were carried out with duration of clean time of not less than 10 hours. For aggregates with a large working width and in the presence of cases when technological stops correspond to more than 25% of the shift time, no less than 3 control shifts were performed with a clean time duration of no less than 9 hours (^{Oficina Nacional de Normalización de Cuba, 2003})

According to ^{De Las Cuevas et al. (2008)}, to determine the technological and exploitation indices considering the NC 34-37 standard and from the timing of the machine to be tested under field conditions, the automated system was used "TECEXP".

This computer tool provides the results of each control shift, considering the volume of work performed, time balance (clean, operational, productive, shift and exploitation) and hourly productivity in eight hours. It also considers fuel consumption per unit of work performed and in operating time, technological and technical damage elimination time, technological and technical safety coefficient, utilization coefficient of productive and operating time.

RESULTS AND DISCUSSION

Timekeeping

The clean working time timing results were 19 hours for the transplanter; 20,05 hours for the subsoiler and 19,02 hours for the Jacto Coral B12 sprayer, complying with the provisions of the Cuban standard taken as a reference for this investigation. During this period, a work volume equal to 7,83 ha was carried out, with a planting distance of 1,15 m between rows and 0,35 cm between plants, with a depth of 6 cm and a working width of 3,45 m. (Table 3).

TABLE 3 Results of work timings of the agricultural sets 

Implements	Clean time, h	Time lost in turns, h	Total operating time, h	Shift time without failures, h	Productive time, h	Operating time, h
Checchi Magli Unitrium transplanter.	19,00	4,54	30,48	30,48	24,80	24,80
Three-body cultivator subsoiler of national manufacture.	20,05	3,12	31,25	31,25	23,37	22,37
Sprayer Jacto Coral B12.	19,02	6,21	50,20	50,20	40,30	37,40

Source: Own elaboration.

Productivity

Greater productivity is appreciated in the clean time work times of the sprayer compared to the other implements evaluated. The clean working time of the sprayer, as it can be seen in Table 4, has higher values, due to the higher speed used for this work, the speed of the Jacto Coral B12 sprayer was 6.20 km / h, the Checchi Magli Unitrium transplanter operated at 1.45 km / h and the modified three-body subsoiler at 5.38 km / h. In the case of the transplanter and the modified subsoiler, as they are integrally coupled, better maneuverability was observed in the turns of the agricultural units.

TABLE 4 Results of work timings of the agricultural sets 

Productivity - ha / h	Clean time, h	Operating time, h	Productive time, h	Shift time without failures, h	Operational time, h
Checchi Magli Unitrium transplanter.	0,41	0,32	0,32	0,26	0,26
Three-body cultivator subsoiler of national manufacture.	1,08	0,95	0,91	0,68	0,68
Sprayer Jacto Coral B12.	4,35	2,17	2,03	1,63	1,63

Source: Own elaboration.

Productivity per Shift Time or Work Day

The sprayer reached the value of 13.03 ha / day, productivity per exploitative time shift (W07), the modified cultivator subsoiler obtained times of 5.45 ha / day in (W07 ) and the Checchi Magli Unitrium transplanter - Deutz Fahr Agrofarm 420-t Ecoline tractor, reached values of 2.06 ha / day in productivity per day of exploitative time (W07), this last value is lower by 17.6% compared to the manual transplant that registered values of 2.50 ha / day, but in this process there was a reduction in labor from 30 laborers to 10 laborers, which produced a reduction in costs in this area ^{Ramos (2018)}.

Calculation of the Economic Effect of the Decreasing in the Workforce

Data for calculating the economic effect of the reduction in labor:

• Cost of daily wage: $ 21, including legal benefits

• Manual sowing: 30 day laborers to sow 2.5 hectares / day.

• Sowing with transplanter: 10 laborers to sow 2.06 hectares / day.

TABLE 5 Manual sowing 

30 day laborers X $ 21 daily =	$ 630 / day
Planting the entire planned area for cultivation took 30 days in the tobacco enterprise
$ 630 / day x 30 days =	$ 18,900 dollars.

Source: Own elaboration.

TABLE 6 Sowing with transplanter 

10 day laborers x $ 21 daily =	$ 210 / day
Planting the entire planned area for cultivation took 30 days in the tobacco enterprise
$ 210 / day x 30 days =	6,300 dollars.

Source: Own elaboration.

The difference in the cost of hiring labor between manual planting and mechanized planting is observed. In terms of the relation cost/benefit the latter is the most commendable to apply, since, despite the fact that the transplanting machine has an approximate cost of 25 000 dollars, which would significantly increase the cost of mechanized transplantation, it is justified by the high profitability of the crop and this machine is paid for in the first year and, in the second year, it will reflect a considerable reduction in the cost of paying wages for the next tobacco production season.

Fuel Consumption

The fuel consumption index: a) per unit of work performed (Ce) L / ha and b) per hour of operating time (Ch) L / h. The one with the lowest fuel consumption in the index (Ce) was the sprayer that obtained a value of 3.25 L / ha and the transplanter reached the index (Ch) of 2.03 L / h (Figure 4). These indices were considered low in comparison with those referred by ^{Chedré Padrón et al (2015)} who during the evaluation of universal tractors, reported that the fuel consumption to carry out the sowing work was 16 L/ha.

FIGURE 4 Fuel consumption: a) per unit of work performed (Ce), b) per hour of time operation (Ch). 

Data for Calculating the Economic Effect of the Decrease in Fuel Spending

• Cost of a gallon of diesel in Ecuador: 1.03 dollars (^{Petroecuador, 2019})

• Cost per liter of diesel in Ecuador: 0.27 dollars (^{Global Petrol Prices, 2019}).

• Fuel consumption in this research 7.90 L / ha.

• 60 Hectares transplanted in the Tobacco Farm Tabaganesha S.A.:

TABLE 7 Fuel consumption during the investigation of the tractor in the transplant work 

7.90 L / ha x 0.27 dollars / liter of diesel =	2.13 dollars / ha.
60 hectares x $ 2.13 / ha =	$ 127.80 Spent on fuel consumption in research, in transplantation.

Comparatively, the expense for fuel consumption is low in relation to data obtained in other investigations where they reflect consumption of up to 16 L / ha (^{Chedré Padrón et al., 2015})

Operational Coefficients

The main operational coefficients of the agricultural sets are presented in (Table 8). It is observed that the lowest value in the utilization coefficient (K07) of the operating time is 0.37, of the sprayer, which can be explained by the loss of time in the turn and squaring the set to carry out the next row. The productive time utilization coefficient (K04) with the highest rank was that of the modified subsoiler, reaching a value of 0.84.

The technological safety coefficient (K41) and technical safety coefficient (K42) reached the maximum value of 1.00 for all the implements evaluated in this research work. This result was due to the fact that the time used in the suppression of technical defects was zero since this machinery had little operating time and its failure rates were very low.

TABLE 8 Operational Coefficients 

Implements	Productive time utilization coefficient (K04)	Operational time utilization coefficient (K07)	Technological safety coefficient (K41)	Technical safety factor (K42)
Checchi Magli Unitrium transplanter.	0,77	0,62	1,00	1,00
Three-body cultivator subsoiler of national manufacture.	0,84	0,63	1,00	1,00
Sprayer Jacto Coral B12.	0,47	0,37	1,00	1,00

Source: Own elaboration

DISCUSSION

^{IDAE (2006)} affirms that the size expressed in hectares, the shape and the regularity of the plot (Figures 5, 6 and 7), are also very significant when evaluating the time lost in turns and the fuel consumption produced by tractors while driving repeatedly on it throughout the work schedule.

That theory was demonstrated in this research and was corroborated, since in several places of the Tabaganesha 2 tobacco farm, such as boundaries, or parcels of irregular or normal shape, a lot of time was lost making turns to square the implement-tractor sets and therefore, more fuel was consumed than it should have.

Source: ^{IDAE 2006}.

FIGURE 5 Rectangular Plot 

Source: ^{IDAE 2006}.

FIGURE 6 Normal Plot  

Source: ^{IDAE 2006}.

FIGURE 7 Irregular Plot 

The Jacto Coral B12 sprayer reached the value of 1.63 ha / h in the productivity index per hour in exploitation time. This result is higher than that stated by ^{Rodríguez Hernández et al. (2008)} that obtained 0.35 ha / h. In turn, he aforementioned author obtained a value of 2.77 ha / day in the productivity index of time per day, while the Jacto Coral B12 sprayer exceeded these value with 13.03 ha / day.

The fuel consumption of the sprayer is fully differentiated by the Jacto Coral B12 sprayer, which obtained a fuel consumption value per unit of work performed (Ce) of 3.25 L / ha, while the authors, ^{Rodríguez Hernández et al. (2008)} obtained a value of 8.53 L / ha, evaluating an 80 hp MTZ-80 tractor unit and a Matabí sprayer with characteristics very similar to those evaluated in this research

^{Chedré Padrón et al (2015)} state that the fuel consumption for mechanized sowing work, using manual feed transplanter, resulted in 16 L / ha, a variable that they consider normal for universal types of tractors. In this assertion, the fuel consumption obtained by the Deutz Fahr Agrofarm 420-T Ecoline tractor and the Checchi Magli Unitrium transplanter are lower, with a value of 7.90 L /, having considerable savings in the benefit-cost ratio of diesel in this work.

The fuel consumption of the tractor-subsoiler unit in the work unit index (Ce) was 5.48 L / ha and per hour of exploitative time (Ch), it was 3.74 L / h, much lower ranges in fuel savings than those obtained by ^{Hilbert, J.A.; Pincu (2000)} in their research where values of 15.3 L / ha for (Ce) and 30.6 L / h for (Ch) were manifested.

For the hilling work in tobacco cultivation with the 6-in-1 multi-plow implements and traditional ridger, a speed of 3.84 km / h was used, on the other hand, with the tractor-subsoiler set, for this same work, in the same crop, a speed of 5.38 km / h was used (^{Lora Cabrera et al., 2008}).

The productivity of the Checchi Magli Unitrium transplanter set - Deutz Fahr Agrofarm 420-t Ecoline tractor by working time - ha / day was 2.06 ha / h; being 17.6% lower compared to manual transplantation (^{Ramos, 2018}). It should be noted that with the application of this machine, the use of labor in this process was considerably reduced, from 30 day laborers to 10 day laborers, which produced a reduction in costs in this area.

CONCLUSIONS

• The results of the technological and operational evaluation of the implement-tractor sets were quite satisfactory for their use in tobacco cultivation (Nicotiana tabacum L.), highlighting the performance of the Checchi Magli Unitrium transplanter set - Deutz Fahr Agrofarm 420 -T Ecoline tractor, since during 19 hours of clean working time, it sowed with 93% effectiveness, with a sowing distance of 1.15 m between rows and 0.35 cm between plants, with a depth of 6 cm and working at a speed of 1, 45 km / h, with a working width of 3.45 m.

• The indices of fuel consumption per unit of work performed (Ce) and the fuel consumption of operation time (Ch) of all the agricultural units evaluated, behaved very favorably, being comparatively lower than what was reported in other investigations.

• In the coefficients of technological (K41) and technical (K42) safety, all the agricultural sets evaluated reached the maximum values of 1.00, since during the evaluation they did not suffer mechanical damage.

• In the productive time utilization coefficient (K04), values were 0.77 for the transplanter, 0.84 for the modified subsoiler and 0.47 for the sprayer, this latest was the lowest rank. The operation time utilization coefficient (K07) was 0.62 in the Checchi Magli Unitrium transplanter, 0.63 in the three-body subsoiler of national manufacture and 0.37 in the Jacto Coral B12 sprayer, relatively low values compared to other coefficients, influenced by the shape of the plot and time losses in the turn of the agricultural sets.

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NOTA

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Received: July 10, 2020; Accepted: December 04, 2020

^*Author for correspondence: Emilio Ramirez-Castro, e-mail: [e-mail]

Emilio Ramírez-Castro, Docente de la Universidad Técnica de Babahoyo UTB, Facultad de Ciencias Agropecuarias FACIAG. Dirección: Babahoyo Km 7 ½ vía Montalvo, Babahoyo, Los Ríos, Ecuador. Magister en Agronomía, mención: Mecanización Agrícola en la Universidad Técnica de Manabí, Cel. 0969188276-0982400642, e-mail: [e-mail]; [e-mail];

Liudmyla Shkiliova, Docente de la Universidad Técnica de Manabí UTM, Facultad de Ingeniería Agrícola, Dirección: Campus Lodana Km 18 Vía Portoviejo, Santa Ana, Portoviejo, Manabí, Ecuador. Cel. 0993702502, e-mail: [e-mail]; [e-mail]

The authors of this work declare no conflict of interests.