Machinery labor fronts. A contribution to management of mechanization in sugarcane production bases

^iDJulio Andrés García-Pérez^IOSDE AZCUBA, Plaza de la Revolución La Habana, Cuba.*✉:olgalidia.alonso@azcuba.cu

^iDPablo Manuel Hernández-Alonso^IIUniversidad Agraria de La Habana, Facultad de Ciencias Técnicas, San José de las Lajas, Mayabeque, Cuba

^iDErnesto Luis Velarde-Sosa^IIIInstituto de Investigaciones de la Caña de Azúcar (INICA), Boyeros, La Habana, Cuba.

^iDEvelio Pausa Bello^IVCentro Nacional de Capacitación (CNCA), AZCUBA, Boyeros, La Habana, Cuba.

^iDDámaso Socarrás-Laza^IVCentro Nacional de Capacitación (CNCA), AZCUBA, Boyeros, La Habana, Cuba.

^IOSDE AZCUBA, Plaza de la Revolución La Habana, Cuba.

^IIUniversidad Agraria de La Habana, Facultad de Ciencias Técnicas, San José de las Lajas, Mayabeque, Cuba

^IIIInstituto de Investigaciones de la Caña de Azúcar (INICA), Boyeros, La Habana, Cuba.

^IVCentro Nacional de Capacitación (CNCA), AZCUBA, Boyeros, La Habana, Cuba.

^*Author for correspondence: Julio Andrés García-Pérez, e-mail:olgalidia.alonso@azcuba.cu

ABSTRACT

Mechanization management in sugarcane production bases today faces difficulties such as the obsolescence of machinery with an average age for tractors higher than 30 years. The high dependence on external services, the duality of the harvesting system where external services are received from modern combines. and a park of old machines is operated by sugar cane production bases such as cooperatives, fragmented into teams of very low productivity, which affects the organization of logistics, technical assistance and the use of transportation. This paper theoretically demonstrates the advantages in machinery management achieved by forming labor fronts with the equipment of two or more bases, to jointly harvest the sugarcane areas. Likewise, the advantages of using the fronts as operational centers for other tasks that can be fulfilled with high quality in unison with the harvest or immediately after it is executed. The implementation of the fronts in the 2021 - 2022 harvest is described, resulting greater productivity for the harvesters grouped in the new system and demonstrating the possibility of achieving greater sugar yield.

Keywords:

Obsolescence, Dependence, External Services, Harvest

Received: 12/10/2023; Accepted: 12/3/2024

Julio Andrés García-Pérez, MSc., Profesor auxiliar, presidente del OSDE AZCUBA, Calle 23 No. 171 / N y O Plaza de la Revolución Habana, Cuba.

Pablo M. Hernández-Alfonso, Dr.C., Profesor Titular, Universidad Agraria de La Habana, Facultad de Ciencias Técnicas, San José de las Lajas, Mayabeque, Cuba, e-mail: phernand@unah.edu.cu.

Ernesto Luis Velarde-Sosa, Dr.C., Investigador, Titular, Instituto de Investigaciones de la Caña de Azúcar (INICA). Carretera a CUJAE, km. 2½, Boyeros, La Habana, Cuba, C.P. 19390, e-mail: evelardesosa@yahoo.es,ernesto.velarde@inica.azcuba.cu.

Evelio Pausa-Bello, Ing. Especialista de Primer Grado en Mecanización Agrícola. Grupo Técnico Asesor a la Mecanización Agrícola, Centro Nacional de Capacitación (CNCA), AZCUBA, Carretera de la CUJAE km 2 ½ Boyeros Habana, Cuba, e-mail: evelio.pausa@cnca.azcuba.cu

Dámaso Socarrás-Laza, Ing. Especialista de Primer Grado en Mecanización Agrícola. Grupo Técnico Asesor a la Mecanización Agrícola, Centro Nacional de Capacitación (CNCA), AZCUBA, Carretera de la CUJAE km 2 ½ Boyeros Habana, Cuba, e-mail: damasosocaras@gmail.com.

The authors of this work declare no conflict of interests.

AUTHOR CONTRIBUTIONS: Conceptualization: J. García, P. Hernández. Data curation: J. García, P. Hernández. Formal análisis, Investigation: J. García, P. Hernández, E. Velarde, E. Pausa, D. Socarrás. Metodología: J. García. Supervision: J. García, P. Hernández. Validation: J. García, P. Hernández, E. Velarde. Roles/Writing, original draft: J. García, P. Hernández, E. Velarde. Writing, review & editing: J. García, P. Hernández, E. Velarde.

The mention of trademarks of specific equipment, instruments or materials is for identification purposes, there being no promotional commitment in relation to them, neither by the authors nor by the publisher.

This article is under license Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

CONTENT

INTRODUCTION

⌅

The need to introduce mechanization in Cuban sugarcane production, particularly in the harvest, stands out in statements by the country's main leaders after 1959, this activity being defined by Che Guevara as the “backbone of agriculture” and pointed out by Fidel Castro: “Since we cannot renounce the harvest, which occupies an important place in our economy, there is no other solution than using machines,…” (Castro, 1962CASTRO, R.F.A.: Discurso, Obra Revolucionaria, 1962.).

The First Agrarian Reform Law Gobierno de Cuba (1959)GOBIERNO DE CUBA: Ley de Reforma Agraria (Primera Ley de Reforma Agraria)., Revolucionaria, 1959. created conditions for an accelerated development of mechanization in the agricultural production bases. The National Institute of Agrarian Reform (INRA), individually gave land only to those who already worked it, promoting the formation of cooperatives in the intervened large estates, with sufficient area for a rational exploitation of agricultural machines, the number of which increased rapidly.

The concentration of areas for the management of agricultural machinery allows the formation of a versatile machine park, operating in teams^†Platoon - specialized group of personnel, agricultural machines and technical assistance means that work with the same location, objective and direction. with a greater operating load per team, thus reducing amortization, salary and technical assistance expenses for the use of machinery in general. and particularly in the harvest, where financial expenditures for the use of harvesters, tractors and means of transportation can amount up to a third of those required for sugar cane production (AZCUBA, 2021bAZCUBA: Tarifas Agrícolas para la Mecanización, Inst. AZCUBA, Dirección de Economía, La Habana, Cuba, Formato digital, 2021b.). Expenditures for workshop services also decrease, knowing that in countries like Brazil a greaser serves about 21 pieces of equipment, a welder between 39 and 51 and a turner between 105 and 121 IDEA (1999)IDEA: Indicadores de desempeño de la agroindustria de la caña de azúcar. Brasil, Zafra 98/99, Inst. IDEA - Instituto de Desarrollo Agroindustrial, Brasil, 11 p., 1999., making these personnel underutilized if they are used in small units.

The search for efficiency in this way led to the formation of organizational units for sugarcane production, including agricultural mechanization, called “districts”, with an area between 2000 and 2500 hectares, divided into “lots” with a net area of 450 hectares, in turn formed by blocks, which are defined as compact areas of 54 to 104 ha Cuellar (2002)CUELLAR, I.: Álvaro Reynoso: 140 años después, Inst. Unidad de impresiones gráficas de Minrex, La Habana, Cuba, 115 p., 2002. destined for the production of cane, with the same variety and subjected to agricultural processes in the same calendar period. Santana et al. (2014)SANTANA, I.; GONZÁLEZ, M.; CRESPO, R.; GUILLEN, S.: Instructivo técnico para el manejo de la caña de azúcar, Ed. INICA, La Habana, Cuba, 302 p., 2014. suggest an area of 100 ha for the blocks, as convenient for the operation of the harvesting system. (Santana et al., 2014SANTANA, I.; GONZÁLEZ, M.; CRESPO, R.; GUILLEN, S.: Instructivo técnico para el manejo de la caña de azúcar, Ed. INICA, La Habana, Cuba, 302 p., 2014.). With a view to their productive organization, the blocks were subdivided into fields.

At the same time, a network of workshops was developed in accordance with the productive structure.

Jorge (2015)JORGE, H.: Variedades de caña de la empresa azucarera La Estrella, Inst. Empresa azucarera La Estrella, 46 p., 2015. describes the existence of moments of maximum ripening in the development of sugarcane, while Rodríguez (2022)RODRÍGUEZ, R.M.: Informe semestral de proyecto: Bases científico técnicas para el reporte agrometeorológico de las áreas cañeras (julio – diciembre de 2022)., Inst. AZCUBA, La Habana, Cuba, 25 p., 2022. explains how the high variability of the climate in sugarcane producing units puts these moments out of phase with respect to what was planned. Consequently, if the harvesting equipment of a unit operates throughout the campaign, the increase in the number of blocks and area to be harvested defines the number of moments of maximum ripening distributed over time and therefore adds possibilities of operating in fields with high potential sugar yield.

FIGURE 1. Variation of POL in varieties from the CALESA company in Panama.

FIGURE 2. Climatic zones of the A. Sánchez company (Information from E. Pérez).

According to AZCUBA (2023)AZCUBA: Procedimiento para realizar la aplicación de las instrucciones metodológicas para el control y aplicación del sistema de precios de la caña por su calidad (SPCC), Inst. AZCUBA, Resolución de 53 de 2023, La Habana, Cuba, 37 p., 2023., the potential sugar yield of cane is estimated by the expression:

R P C = 1,5 * P O L (1 - (F i b e r + 6,5) / 100) - 0,5 * B r i x (1 - (F i b r a + 3) / 100)

(1)

And the net price of cane according to:

P C N = R P C * F F (p e s o / t)

(2)

Where: FF is a fixed factor equivalent for year 2023 to 71.89, which determines income considering the RPC of net cane.^††Net cane - cane without foreign matter.

Harvesting cane with the highest POL and Brix at the lowest cost summarizes the objectives of planning the harvest machinery and the increase in the number of blocks or moments of maximum ripening correlates with them. In the 90 s, the disintegration of the socialist camp affected the foundations of the Cuban sugar agroindustry, which was not sustainable in a context of low sugar prices in the market. This forced it to increase its resilience, reducing the number of sugar factories to 61, the area destined for sugarcane production to 886,470 ha and the number of tractors and harvesters to about 1.5 units per 100 ha ONEI (2020)ONEI: Anuario estadístico de Cuba 2019. Edición 2020, Inst. Oficina Nacional de Estadistica e Informacion, La Habana, Cuba, 2020. with low technical availability due to insufficient renewal, shortage of parts and supplies and progressive decapitalization of the workshop network. Changes were made in the forms of agricultural management and mechanization, reshaping the productive base from mostly state-owned with its management concentrated in districts to mostly agricultural cooperatives. In this way, the advantages of the state form of production on district and company scale, designed for conditions of resource sufficiency, were partially renounced by a new management system, enhancing the sense of responsibility over resources being property of the cooperative members, and greater quality demands for the labors. Figure 3 illustrates the variability of the area of the 1008 productive bases with sugarcane production (AZCUBA, 2022AZCUBA: Base de datos sobre composición de bases productivas, Inst. AZCUBA, Dirección de Agrotecnia, Informe técnico, La Habana, Cuba, 2022.). It shows that in 53.5% of them it does not exceed 540 hectares and in 87% it does not exceed 1080 hectares, which implies a significant reduction with respect to the area of the old districts.

FIGURE 3. Productive units structure of according to their agricultural area.

In 2008, a process of recovery of sugarcane agriculture began, which includes mechanization activity, acquiring new equipment to be operated in the harvest and other activities by state service units, among them: more productive combines Case 7000 models, 7700 and later 8800, along with trucks and trailers with 20 t loading capacity and high-power tractors and modern agricultural implements. This resulted in the creation of a new harvesting system and the formation of machinery specialized groups for farming activities and cultural services. However, the service capacity created with the new combines covered only about 50% of the needs, and the new system had to coexist with the old one, formed by the numerous groups of obsolete KTP2M model combines with very low productivity, which became managed by the productive bases when the districts were fragmented, with a very narrow horizon for programming, limited to the fields that are not harvested with the modern system, in the environment of the cooperative unit that operates them. This makes it difficult to carry out opportunity planning throughout the campaign, where the use of the harvesters coincides with the optimal moment to execute the processes. An example of the dispersion of resources caused by the elimination of the districts is that in the 2020 to 2021 harvest, the operation of 481 KTP2M groups included 85 with a single machine and 340 with two (AZCUBA, 2021aAZCUBA: Balance de maquinaria para la zafra 2021 a 2022, Inst. AZCUBA, Dirección de mecanización, 2021a.). This not only leads to planning difficulties, it also makes technical assistance and the distribution of parts fuel and other supplies difficult, in addition to affecting transport management.

The lack of renewal of the machinery of the productive bases makes them extremely dependent on the service units, a situation that must change at least in cultivation labors, where there is a preference in the productive bases to carry them out with their own resources (CNCA-AZCUBA, 2020CNCA-AZCUBA: Diagnóstico técnico de la mecanización agrícola de la base productiva en el Central Cinco de Septiembre, Inst. AZCUBA, Informe técnico, La Habana, Cuba, 25 p., 2020.). For this reason, they are gradually being equipped with medium-power Belarus 1025 model tractors and new implements, such as the AZ301 fertilizer cultivator (see Figure 4), which simultaneously carries out fertilization and traditional cultivation and, unlike the implements used until now by these bases, they have a high passage capacity between the stubble of the recently harvested cane.

However, the small areas of most of the cooperatives^†††CPA - agricultural production cooperative; UBPC - Basic unit of cooperative production. In the CPA, farmers are owners of the land, in the UBPC - usufructuaries. makes the organization of machinery groups to carry out labors in addition to harvesting economically ineffective and prevents using the advantages this form of organization represents for the control of activities, technical assistance of equipment, logistical attention and protection of machinery.

FIGURE 4. AZ301 Cultivator Fertilizer.

On the other hand, the rate of harvesting areas by the KTP2M combine harvester teams is very low in comparison with the cultivation teams, which affects the organization of those cultivation activities that should be carried out immediately. after harvest, regardless of the equipment's ability to avoid clogging with residue from that operation. The main objective of this paper is to establish labor fronts that integrate the harvesting teams and other equipment and resources of two or more production bases, including the following tasks.

Harvest the area of the units integrated in the front as a whole, achieving with the increase of total area in plan, an adequate varietal and planting strategy, the increase of alternatives to harvest fields with maximum sugarcane maturity.
Increase the productivity of harvesters and reduce harvesting expenses through better use of transportation, together with greater availability and technical security, based on the fact that the concentration of machinery makes technical assistance and distribution of parts and supplies easier.
Integrate in the labor front the cultivation activities that must be carried out simultaneously with the harvest or immediately after, which include:
The application of hormonal herbicides using the “harvest and apply” method, which consists of installing a sprinkler mechanism on the harvester itself, with the particularity that the herbicides are deposited on the ground when the agricultural residues are still inside the harvester.
1. Fertilization and first cultivation, considering that the introduction of the AZ301 fertilizer cultivator with high passage capacity and the increase in productivity of the set of machines as a result of the integration of teams, creates conditions for this purpose.

This work does not delve into the third task because:

The “harvest and apply” method or system is a technology already evaluated as effective and is in the process of generalization, whose presence in a work front is fully justified.
Cultivation and fertilization immediately after harvest is agronomically based by different authors (Martín et al., 1987MARTÍN, O.J.; GÁLVEZ, R.G.; DE ARMAS, U.R.; ESPINOSA, O.R.; VIGOA, H.R.; LEÓN, M.A.: La Caña de Azúcar en Cuba, Ed. Editorial del Ministerio de Cultura, primera ed., La Habana, Cuba, 612 p., 1987.; MINAZ-Cuba, 2000MINAZ- CUBA: Fundamentos Técnicos Prácticos del Cultivo de la Caña de Azúcar, Inst. Ministerio de la Industria Azucarera (MINAZ). Organismo central, La Habana, Cuba, 21 p., 2000.; Santana et al., 2014SANTANA, I.; GONZÁLEZ, M.; CRESPO, R.; GUILLEN, S.: Instructivo técnico para el manejo de la caña de azúcar, Ed. INICA, La Habana, Cuba, 302 p., 2014.), the technical reasons that prevented its application in those conditions are They are eliminated with the formation of the fronts and introduction of the AZ301 high-throughput fertilizer cultivator. The construction innovations that characterize it will be the subject of other works.

Theoretical and methodological fundaments

⌅

Figure 5 shows the conception of the front in a block diagram, where the input factors are N1 -the number of harvesters with “harvest and application” systems, N2 - a group of transport resources, the necessary maintenance, direction and fire protection systems. and an AZ301 fertilizer cultivator. As output factors stand the profit for a better price due to harvesting cane with higher sugar content (I1), lower expenses for harvesting and transportation (I2), lower expenses for carrying out chemical weed control together with the harvest (I3). , as well as overall cultivation and fertilization (I4), and benefits from being able to carry out cultural operations at an ideal time (I5) and from facilities in supply and external technical assistance due to the concentration of equipment (I6), all in specific climate, soil and territory conditions.

The main parameter of the front consists of the number of combines (N1). In order to simplify the analysis of its dimensions, the ratio of transport and harvesters (N2/N1) is assumed to be constant, as well as that the described front has a basic level, where the dimensions of the direction, maintenance system, fire protection system are also proportional to the number of harvesters (N1)^††††In a fundamentally cooperative productive base, the fronts are formed by the union of machines from different cooperatives under the conditions that they agree upon and with common use of cane transport, in order to coincide in the areas with greater sugar cane maturity defined in the plan of the company. A higher level of front arises when the parties agree to achieve savings, by reducing other means and equipment by giving common use to existing ones., as are the expenses incurred in their operation.

FIGURE 5. The front in block diagram.

Obtained information is not enough to estimate the dimensions of I5 and I6 and therefore they are not considered in this paper, although they appear in the block diagram since their existence is evident.

The dimension of the front is generally established considering the average areas destined for harvest, having reached maximum maturity and this in turn is the result of a planting strategy where distant and nearby blocks are balanced, avoiding transport overloads and considering possible effects of early rainfall on the transit capacity of harvesting and transportation means. In order to obtain lower harvesting expenses on the fronts, the aim is to increase the operating time of the combines, which is the only "measurable" time with the technical limitations of the production base based on knowledge of the total engine hours and transportation hours.

T_{02} = h m o t o r_{t o t a l} - h m o t o r_{t r a n s i t b e t w e e n f i e l d s}

(3)

and in the absence of recording equipment it is easier to estimate. The average value of the set of combines in the front can be expressed as:

\sum_{i = 1}^{N} T_{02 i} = \sum_{i = 1}^{N} h m o t o r_{t o t a l i} - \sum_{i = 1}^{N} h m o t o r_{t t r a n s i t b e t w e e n f i e l d s i}

(4)

The operational effectiveness criteria ( $E_{02}$ ) is proposed, which is equivalent to the relationship between operating time and exploitation time or productivities in both times.

E_{02} = \frac{T_{02}}{T_{07}} = \frac{W_{07}}{W_{02}}

(5)

Where $W_{02} y W_{07 -},$ productivity in operational and exploitative times respectively.

So, the productivity in exploitative time becomes:

W_{07} = W_{02} \times E_{02,} t / h_{e x p l o i t a t i o n}

(6)

By forming the front it is estimated to obtain a greater value of $E_{02,}$ due to the facilities obtained by concentrating machines regarding supply and external technical assistance, as well as better use of transportation.

It is necessary to point out that an excessive increase in the dimension of the front leads to an increase in travel time, affecting operating time and productivity in exploitation time, which subtracts operating time and can contribute to the opposite effect, reducing $E_{02,}$ and consequently I2, which is admissible as long as this reduction is compensated by increases in I1, I3, I4. considering that:

(I 1 + I 2 + I 3 + I 4) \to M a x (p e s o / t)

(7)

The front as a facilitator of increased operational effectiveness

⌅

The system of harvesting and supplying cane to the sugar mill can be considered as part of a chain production system, where according to Rodríguez-López et al. (2020)RODRÍGUEZ-LÓPEZ, Y.; MOREJÓN-MESA, Y.; CRUZ-ARREDONDO, C.; MARTÍNEZ-BAO, O.: “Organización racional del complejo cosecha-transporte en caña de azúcar con la integración de modelos matemáticos”, Revista Ciencias Técnicas Agropecuarias, 29(3): 50-61, 2020, ISSN: 2071-0054. [16], citing Kletskin, Pavlovki, Saakian, Finov and Tsinan, Jodosh, Zhalnin, Puskariov and Iglesias, a system of this type with several links, requires that the following expression on flow continuity be fulfilled:

X_{1} \leq X_{2} \leq X_{3} \leq X_{4}

(8)

In these: $X_{1}$ , $X_{2},$ $X_{3},$ $X_{4},$ are equivalent to the average productivities of each link in the system at each moment of the day, which are equal to the sum of the productivities of the set of j pieces of equipment intended for the same purpose.

X_{i} = \sum_{j = 1}^{n} W_{ij}

From them: $X_{1} -$ harvest productivity; $X_{2} -$ transportation productivity in the field to the cleaning center; $X_{3} -$ in the cleaning center; $X_{4}$ - on the railway.

The concept of equal or higher productivity in successive stages $X_{i} \leq X_{i + 1}$ , defines the system's capacity to face eventualities.

Expression (8) $X_{1} \leq X_{2} \leq X_{3} \leq X_{4}$ presents a limited vision of the requirement of balance since it does not analyze the variation in productivity in the links due to the preceding link and the first link - the harvest.

The combine´s principal-time productivity can be expressed as:

W_{1} = 0,1 * V_{C} * B * R_{a} (t/h)

(9)

Where: V - working speed; B - working width; $R_{a}$ - agricultural performance.

Productivity in operation time can be defined as:

W_{02} = 0,1 \times B \times V_{c} \times R_{a} \times K_{02} (t/h)

(10)

Where: $K_{02}$ - coefficient showing the relation of principal and operation times. $K_{02} = \frac{T_{1}}{T_{02}}$

In turn, productivity in exploitation time is expressed as:

W_{07} = 0,1 * V * B * R_{a} * K_{07} (ha/h)

(11)

Where: $K_{07}$ - coefficient for the use of exploitative time, relating principal and exploitative times. $K_{07} = \frac{T_{1}}{T_{07}}$

$T_{1}$ , $T_{02}$ , $T_{07}$ , $K_{02}$ , $K_{07}$ , correspond as symbols with current standards and procedures (Iagric:-Cuba, 2013IAGRIC -CUBA: Sistema de Gestión de la calidad. Prueba de máquinas agrícolas. Evaluación tecnológica y de explotación, Inst. Ministerio dela Agricultura, PNO PG-CA-043, La Habana, Cuba, 13 p., 2013.).

An analysis of expressions 9 $W_{1} = 0,1 * V_{C} * B * R_{a} (t/h)$ , 10 $W_{02} = 0,1 \times B \times V_{c} \times R_{a} \times K_{02} (t/h)$ and 11 $W_{07} = 0,1 * V * B * R_{a} * K_{07} (ha/h)$ shows the high variability of $X_{1}$ , given that:

Working speed of the combines depends on the relationship between the cane mass input capacity that the machine allows with its working width and the agricultural yield Matos-Rodríguez (2012)MATOS-RODRÍGUEZ, N.: Organización Racional del Complejo de Máquinas en la Cosecha, Transporte, Recepción de la caña de Azúcar en la Empresa Azucarera Argentina, Universidad Agraria de La Habana “Fructuoso Rodríguez Pérez”, Tesis en Opción del grado Científico de Doctor en Ciencias Técnicas Agrícolas., San José de las Lajas, Mayabeque, Cuba, 178 p., 2012.; Matos-Ramírez et al. (2014)MATOS-RAMÍREZ, N.; IGLESIAS-CORONEL, C.; GARCÍA-CISNEROS, E.: “Organización racional del complejo de máquinas en la cosecha-transporte-recepción de la caña de azúcar en la Empresa Azucarera ARGENTINA”, Revista Ciencias Técnicas Agropecuarias, 23(2): 27-33, 2014, ISSN: 2071-0054., which generally ranges between 15 and 80 t/ha and the preparation of the field to ensure the cutting quality Díaz (2011)DÍAZ, R.: Manual del pelotón. Explotación e ingeniería de mantenimiento de cosechadoras de caña de azúcar KTP 2., Ed. MINAZ, primera ed., La Habana, Cuba, 79 p., 2011.; Norris (2014)NORRIS, C.: Curso de Adiestramiento en la Cosecha de Caña, Inst. “Nicaragua Sugar Estates Limited”, San Antonio, Nicaragua, 2014., which is generally unsatisfactory.
$K_{07}$ depends on very diverse factors such as the conformation of the fields, the technical and technological safety of the equipment and maintenance times, in addition to the humidity of the environment and the level of weeds, factors of work organization and availability of transportation to unload the mass of harvested cane, which may be insufficient.

Considering the above, expression (8) $X_{1} \leq X_{2} \leq X_{3} \leq X_{4}$ must take the form:

(\bar{X_{1}} + Δ x_{1}) \leq (\bar{X_{2}} + Δ x_{2}) \leq (\bar{X_{3}} + Δ x_{1}) \leq (\bar{X_{4}} + Δ x_{4})

(12)

Harvest

Transportation to Cleaning Center

Process Center: Cleaning

Rail transport

For 95% of the events in a normal distribution, the productivity deviation in a platoon of “n” machines are within a predictable limit by integrating the standard deviation of the productivity of the different machines.

Δ x_{1} \leq 2 * σ_{x p} = 2 * \sqrt{σ_{x a 1}^{2} + σ_{x a 2}^{2} + σ_{x a 3}^{2} \dots .. σ_{x a n}^{2}}

(13)

Similarly, the deviation of the productivity of the group of harvest teams and therefore of the harvest productivity, which must be assimilated by the rest of the links in the production chain can be estimated as:

Δ x_{1} \leq 2 * \sqrt{σ_{x p 1}^{2} + σ_{x p 2}^{2} + σ_{x p 3}^{2} \dots .. σ_{x p n}^{2}}

(14)

Considering an ideal condition, where all platoons work in a close area, the amount of transportation required to assimilate the maximum expected variation in productivity would be:

Δ x_{2.1} \geq T U * 2 * \sqrt{σ_{x p 1}^{2} + σ_{x p 2}^{2} + σ_{x p 3}^{2} \dots .. σ_{x p n}^{2}}

(15)

Where: $T U$ is the amount of transportation required per unit of mass harvested.

However, if the teams work in areas not close to each other, then the transport must compensate for the variations of each independent team:

Δ x_{2.2} \geq T U * 2 * (σ_{x p 1} + σ_{x p 2} + σ_{x p 3} + σ_{x p 4})

(16)

Being evident that: $Δ x_{2.2} \geq Δ x_{2.1}$ so, that the grouping of teams in fronts, where this is possible, allows a balance of machinery with a smaller amount of transport and consequently greater operational efficiency.

By forming labor fronts, it is possible to reduce the moments of failure, where transportation is paralyzed due to being no harvesters available.

If the harvesters are: Operational or Non-Operational and the probability of occurrence of both events in a machine is known: Pr(“operational”) and Pr(“non-operational), then the probability of a combination x with i operational machines in a team of N machines would be: $\Pr (i o p e r a t i o n a l) = \Pr {(" operational ")}^{i} * P r {(" n o n o p e r a t i o n a l ")}^{N - i}$ (16)

The set of possible combinations with operational and non-operational machines in a team of N machines is:

C = 2^{N - 1}

The probability that i equals the number of operating machines, considering the total number of combinations with these characteristics is:

P r t o t a l (i o p e r a t i o n a l) = \sum_{x = 1}^{j} P r {(i o p e r a t i o n a l)}_{x}

(17)

Where: j is the number of combinations with i operating machines.

The graph in figure 6 illustrates the above said, where pton equals team.

FIGURE 6. Probability of having operational machines

It is built, considering that the lack of technical availability, breakages and the execution of maintenance occupies 35% of the combine's working day, observing that if the team is made up of a single isolated machine, the probability of not being operational is 35%, if it is two - the probability that none is available is 12.25%, if it is three - 4.29% and if it is five - 0.53%.

Evaluation methodology

⌅

In order to evaluate the benefits of integrating harvest teams into fronts, during the 2021 to 2022 harvest, a set of tests were carried out at Antonio Sánchez EAAZ, forming three labor fronts and maintaining two productive bases without integration as in the previous campaign

Front 1 Bases Antero Reglado + Regadío. Área with s. caña - 2034 ha.
Front 2 Bases Desquite + Rev. de Octubre. Área growing s, cane - 2053 ha.
Front 3 Bases Victoria + Chapeo. Área con caña - 2365 ha.
Team 1. Base Vietnam. Área con caña - 2034 ha.
Team 2. Base 21 de Septiembre. Área con caña - 2034 ha.
Witness 2

The attached table shows the equipment that both the fronts and witnesses had.

TABLE 1. Equipment of fronts and witnesses

Equipo	Frente 1 - Antero Regalado+Regadío	Testigo 1. Vietnam	Testigo 2. CPA 21 de Septiembre	Frente 2. - Desquite + R. Octubre	Frente 3. - Victoria + Chapeo
Harvesters KTP2M	5	3	2	5	5
Trucks	10	5	2	7	9
truck trailers	10	5	3	7	9
moving tractors	2	2	1	2	3
daily cutting task	500 t	500 t	140 t	380 t	520 t

The aspects evaluated were the following:

Fronts formation to increase sugar cane yield at harvest time.

The potential sugar yield of cane was compared in the fortnights of January and February of 2021 and 2022 based on laboratory tests of the plantations in the planning phase of their harvest, determining the POL, Brix and amount of fiber and calculating their potential performance by expression (1) $R P C = 1,5 * P O L (1 - (F i b e r + 6,5) / 100) - 0,5 * B r i x (1 - (F i b r a + 3) / 100)$ . What was done constitutes a two-level evaluation. Level A represents the results of harvesters working in 2021 without forming teams. The average cane surface of all units within independent teams turned to be 1262 ha.

Level B represents the results of harvesters working in 2022. Average Cane surface of the units that took part in the 2022 campaign, turned out to be 2062 ha with an increase of 63%. where those that formed fronts were considered as a single unit.

The actual performance of the mill was not analyzed, as it was seriously affected by factors unrelated to the harvest schedule.

Evaluation of the exploitation of harvesting machinery.

The results in the exploitation of harvesters forming fronts and team’s machinery was compared based on four parameters:

The average productivity of the combines per workday
The technical availability of the machines 'according to $D T = 100 * \frac{d_{r}}{D E}$ , relating actual work days of the combines versus effective days.
Operational efficiency of combines $(E_{02}$ ) according to expression (5) $E_{02} = \frac{T_{02}}{T_{07}} = \frac{W_{07}}{W_{02}}$ .
The relationship between the time lost due to transportation and the mass harvested, considering it as a productive dimension of the group of machines.

Data obtained was subjected to simple variance analysis.

Economic Impact Assessment.

Economic impact is analyzed from the profit obtained by comparing the price of cane according to its RPC in 2022 and 2021 according to expression (2) $P C N = R P C * F F (p e s o / t)$ and from the greater productivity of the machines at the same time, considering the established hourly rates (3) $T_{02} = h m o t o r_{t o t a l} - h m o t o r_{t r a n s i t b e t w e e n f i e l d s}$ .

RESULT AND DISCUSSION

⌅

The formation of labor fronts significantly increased the possibility of harvesting cane with a higher degree of ripeness by the CPA and UBPC that formed these fronts. Figure 7 compares the POL, Brix and Fiber obtained in the two fortnights of January and the two of February of the year 2021 and 2022, also presenting the calculation of the RPC, which turned out to be 2.15 points higher in the first half of January and between 1.19 and 1.35 points in the rest, demonstrating the goodness of planning the harvest when the total area to be harvested by a given group of machines is greater. The possibility of a bias in the results due to climatic differences in the years compared was assessed, proving that in the stage before the harvest and in the months of January and February they were similar.

The conditions in which the 2022 campaign was developed with a lack of fuel, lubricants, mechanical components, in addition to industrial failures make it difficult to accurately evaluate some advantages to be obtained by the grouping of harvest platoons as a better use of technical assistance and logistics. However, in the conditions of the harvest itself at Antonio Sánchez EAAZ, where the available transportation ranged between 50 and 75% of that defined in the pre-harvest balance, the probabilistic analysis carried out when theoretically basing the constitution of the fronts, associating or merging the small platoons was effective. There was a consensus among the managers that without the formation of fronts the mechanized harvest of 2022 in that company would have had great difficulties. Figures 8 (a, b) show the advantages in productivity and technical availability of the fronts compared to the control platoons in 2022.

FIGURE 7. Increase in the potential yield of the cane.

On February 2021, when the UBPC and CPA that made up the new fronts operated independently, the first place in machine productivity (t/day - machine in operation) and production per machine (t/machine) corresponded to witness T1. (UBPC Vietnam) formed in both the 2021 and 2022 campaigns by a single platoon of three machines, while in the 2022 campaign the best results were obtained by the 1st, 4th and 5th fronts formed by uniting platoons of units with five and four harvesters respectively, relegating the witnesses made up of isolated platoons.

FIGURE 8. Comparison of fronts and witnesses.8A compares productivity per day; 8B compares technical availability.

In turn, figure 9 compares the operational effectiveness of teams and fronts, highlighting front 1 with $E_{02} = 0.48.$ All fronts evaluated had an operational efficiency 3% to 15% higher than that of the best control team (UBPC Vietnam).

FIGURE 9. Comparison of the Operational Effectiveness of fronts and teams.

An important cause of the changes in the positioning of the fronts lies in a better use of transportation, which as demonstrated significantly influences operational effectiveness. Table 2 illustrates this by showing the time lost due to transportation of fronts one and three and control T1. The table provides data on the total time lost, relating it to the cane harvested given that these are groups with different work results.

TABLE 2. Stop time due to lack of transportation

Evaluated parameter	Fronts and witnesses
Evaluated parameter	A. Regalado + Regadío (F1)	Vietnam (T1)	Victoria + Chapeo (F3)
Fronts and witnesses (t)	14881,7	7596,12	15230
Hours lost due to transportation	398:57:12	225:50:12	286:30:00
Ratio of time lost due to transportation/harvested mass	0:01:37	0:01:47	0:01:08
Percentage advantage	9,83%	---	36,73%

As a result of the increase in RCP shown in Figure 7, with the formation of fronts a higher price for sugarcane was estimated. Figure 10 shows a comparison of the months of January and February for the two campaigns evaluated. The additional potential income (IPA) from the sale of net cane for the productive bases in 2022 was 85 to 154 pesos/t with an average value of 119 pesos/tcn. Assuming 15% impurities, this would be 101 pesos per ton of raw cane.

Considering the experimental results, for a yield of 30 to 40 t/ha (average value 35 t/ha), if $E_{02}$ =0,42, it can be estimated that $W_{07} =$ 6,9 t raw cane/h with 15% foreign matter, which considering the hourly rate of the harvester AZCUBA (2021 b)AZCUBA: Tarifas Agrícolas para la Mecanización, Inst. AZCUBA, Dirección de Economía, La Habana, Cuba, Formato digital, 2021b. [3], leads to an expense of 80.8 pesos/t gross cane (tcb) and 95 pesos/t net cane (tcn). The experimental results show that the fronts allowed an increase in operational efficiency between 2.8% and 13.5% compared to the best indicator of the control platoons, which is directly reflected in the productivity of the combines. Likewise, the increase in the latter according to the data reflected in figure 8 ranges between 8 and 32%, where the performance of the fields influences.

Considering that the activity in fronts allowed an increase in productivity of 8%, there is an expense per ton of raw cane of 74.8 pesos with a reduction of 6 pesos/tcb and 88 pesos per net ton for a reduction of 7 pesos. /tcn, which can be considered as minimal impacts of the use of harvesters on fronts, which taken to harvested area is equivalent to 245 pesos/ha.

It can be seen that the income from better harvest scheduling is between 5 and 15 times greater than that obtained from better exploitation of the machinery.

FIGURE 10. Comparison of income per net cane.

Frentes de trabajo. Una contribución a la gestión de mecanización en las bases productivas cañeras

^iDJulio Andrés García-Pérez^IOSDE AZCUBA, Plaza de la Revolución La Habana, Cuba.*✉:olgalidia.alonso@azcuba.cu

^iDPablo Manuel Hernández-Alonso^IIUniversidad Agraria de La Habana, Facultad de Ciencias Técnicas, San José de las Lajas, Mayabeque, Cuba

^iDErnesto Luis Velarde-Sosa^IIIInstituto de Investigaciones de la Caña de Azúcar (INICA), Boyeros, La Habana, Cuba.

^iDEvelio Pausa Bello^IVCentro Nacional de Capacitación (CNCA), AZCUBA, Boyeros, La Habana, Cuba.

^iDDámaso Socarrás-Laza^IVCentro Nacional de Capacitación (CNCA), AZCUBA, Boyeros, La Habana, Cuba.

^IOSDE AZCUBA, Plaza de la Revolución La Habana, Cuba.

^IIUniversidad Agraria de La Habana, Facultad de Ciencias Técnicas, San José de las Lajas, Mayabeque, Cuba

^IIIInstituto de Investigaciones de la Caña de Azúcar (INICA), Boyeros, La Habana, Cuba.

^IVCentro Nacional de Capacitación (CNCA), AZCUBA, Boyeros, La Habana, Cuba.

^*Autor para correspondencia: Julio Andrés García-Pérez, e-mail:olgalidia.alonso@azcuba.cu

RESUMEN

La gestión de mecanización en las bases productivas cañeras hoy enfrenta como dificultades la obsolescencia de la maquinaria con edad promedio que supera los 30 años en los tractores, la alta dependencia de servicios externos, la dualidad del sistema de cosecha donde se reciben servicios de cosechadoras modernas y se opera un parque de máquinas antiguas fragmentado en pelotones de muy baja productividad, lo cual afecta la organización de la logística, la asistencia técnica y el uso del transporte. El trabajo demuestra teóricamente las ventajas en la gestión de maquinarias de la formación de frentes de trabajo que agrupen la operación de dos o más pelotones para cosechar en común las áreas cañeras de las bases productivas que los operan. Asimismo, se exponen las ventajas de utilizar los frentes como base de operaciones de otras labores que pueden realizarse con alta calidad al unísono con la cosecha o inmediatamente después de la misma. Se describe la implementación de los frentes en la zafra de 2021 a 2022, lográndose mayor productividad en los pelotones agrupados en el nuevo sistema y demostrándose la posibilidad de lograr un mayor rendimiento azucarero.

Palabras clave:

obsolescencia, dependencia, servicios externos, cosecha

INTRODUCCIÓN

⌅

La necesidad de introducir la mecanización en la producción cañera cubana y particularmente en la cosecha, resalta en pronunciamientos de los principales dirigentes del país después de 1959, definiéndose esta actividad por Che Guevara como “columna vertebral de la agricultura” y señalándose por Fidel Castro: “Puesto que no podemos renunciar a la zafra, que ocupa un lugar importante en nuestra economía, no hay otra solución que recurrir a las máquinas, …” (Castro, 1962CASTRO, R.F.A.: Discurso, Obra Revolucionaria, 1962.).

La Primera Ley de Reforma Agraria (Gobierno de Cuba, 1959GOBIERNO DE CUBA: Ley de Reforma Agraria (Primera Ley de Reforma Agraria)., Revolucionaria, 1959.) creó condiciones para un desarrollo acelerado de la mecanización en la base productiva agrícola. El Instituto Nacional de Reforma Agraria (INRA), realizó la entrega individual de la tierra solo a los que ya la trabajaban, potenciando la formación de cooperativas en los latifundios intervenidos, con área suficiente para una explotación racional de máquinas agrícolas, cuya cantidad se incrementó aceleradamente.

La concentración de áreas para la gestión de esa actividad permite la conformación de un parque de máquinas versátil, operando en pelotones^†Pelotón -grupo especializado de personal, máquinas agrícolas y medios de asistencia técnica que trabajan con una misma ubicación, objetivo y dirección. con mayor carga de explotación por equipo, reduciéndose así los gastos de amortización, salario y asistencia técnica para el uso de la maquinaria en general y particularmente en la cosecha, donde las erogaciones financieras por uso de cosechadoras, tractores y medios de transporte pueden ascender hasta un tercio de las requeridas para la producción de caña (AZCUBA, 2021 bAZCUBA: Tarifas Agrícolas para la Mecanización, Inst. AZCUBA, Dirección de Economía, La Habana, Cuba, Formato digital, 2021b.). Disminuyen, asimismo, las erogaciones por servicios de taller, conociéndose que en países como Brasil un engrasador atiende cerca de 21 equipos, un soldador entre 39 y 51 y un tornero entre 105 y 121 (IDEA, 1999IDEA: Indicadores de desempeño de la agroindustria de la caña de azúcar. Brasil, Zafra 98/99, Inst. IDEA - Instituto de Desarrollo Agroindustrial, Brasil, 11 p., 1999.), subutilizándose este personal de utilizarse en pequeñas unidades.

La búsqueda de eficiencia por esta vía conllevó a la formación de unidades organizativas para la producción cañera, incluida la mecanización agrícola, denominadas “distritos”, con una superficie entre 2000 y 2500 ha, divididos en “lotes” con área neta de 450 ha, a su vez formados por bloques, que se definen como áreas compactas de 54 a 104 ha según (Cuellar, 2002CUELLAR, I.: Álvaro Reynoso: 140 años después, Inst. Unidad de impresiones gráficas de Minrex, La Habana, Cuba, 115 p., 2002.) destinadas a la producción de caña, con la misma variedad y sometidas a los diferentes procesos agrícolas en un mismo período del calendario. (Santana et al., 2014SANTANA, I.; GONZÁLEZ, M.; CRESPO, R.; GUILLEN, S.: Instructivo técnico para el manejo de la caña de azúcar, Ed. INICA, La Habana, Cuba, 302 p., 2014.) sugieren para los bloques una superficie de 100 ha, como conveniente para la operación del sistema de cosecha (Santana et al., 2014SANTANA, I.; GONZÁLEZ, M.; CRESPO, R.; GUILLEN, S.: Instructivo técnico para el manejo de la caña de azúcar, Ed. INICA, La Habana, Cuba, 302 p., 2014.). Con vistas a su organización productiva, los bloques se subdividieron en campos.

Paralelamente, se desarrolló una red de talleres acorde con la estructura productiva.

(Jorge, 2015JORGE, H.: Variedades de caña de la empresa azucarera La Estrella, Inst. Empresa azucarera La Estrella, 46 p., 2015.) describe la existencia de momentos de máxima maduración en el desarrollo de la caña, mientras que (Rodríguez, 2022RODRÍGUEZ, R.M.: Informe semestral de proyecto: Bases científico técnicas para el reporte agrometeorológico de las áreas cañeras (julio – diciembre de 2022)., Inst. AZCUBA, La Habana, Cuba, 25 p., 2022.) expone como la elevada variabilidad del clima en las unidades productoras de caña desfasa esos momentos respecto a lo planificado. En consecuencia, si los equipos de zafra de una unidad funcionan durante toda la campaña, el aumento de la cantidad de bloques y superficie a cosechar se traduce en la cantidad de momentos de máxima maduración distribuidos en el tiempo y por tanto de operación en campos con elevado rendimiento potencial de azúcar.

FIGURA 1. Variación del POL en variedades de la empresa CALESA de Panamá.

FIGURA 2. Zonas climáticas de la empresa A. Sánchez (Información de E. Pérez).

Según la resolución 53 de (AZCUBA, 2023AZCUBA: Procedimiento para realizar la aplicación de las instrucciones metodológicas para el control y aplicación del sistema de precios de la caña por su calidad (SPCC), Inst. AZCUBA, Resolución de 53 de 2023, La Habana, Cuba, 37 p., 2023.), el rendimiento azucarero potencial de la caña se estima mediante la expresión:

R P C = 1,5 * P O L (1 - (F i b r a + 6,5) / 100) - 0,5 * B r i x (1 - (F i b r a + 3) / 100)

(1)

Y el precio de la caña neto según:

P C N = R P C * F F (peso/t)

(2)

donde: FF es un factor fijo equivalente para 2023 a 71,89, que determina los ingresos considerando el RPC de la caña neta^††Caña neta - caña sin materias extrañas..

La recolección de la caña con los mayores POL y Brix al menor costo resume los objetivos de la planificación de la maquinaria de zafra y el incremento de la cantidad de bloques o momentos de máxima maduración se correlaciona con los mismos.

En la década del 90, la desintegración del campo socialista afectó las bases de la agroindustria azucarera cubana, que no resultó sostenible en un contexto de bajos precios del azúcar en el mercado. Ello obligó a incrementar su resiliencia, reduciendo el número de centrales a 61, el área destinada a producción de caña a 886470 ha y el número de tractores y cosechadoras a cerca de 1,5 unidades por 100 ha (ONEI, 2020ONEI: Anuario estadístico de Cuba 2019. Edición 2020, Inst. Oficina Nacional de Estadistica e Informacion, La Habana, Cuba, 2020.) con baja disponibilidad técnica debido a la insuficiente renovación, escasez de piezas e insumos y descapitalización progresiva de la red de talleres. Se realizaron cambios en la forma de gestión agrícola y de la mecanización reconformándose la base productiva de mayoritariamente estatal con su gestión concentrada en distritos a mayoritariamente cooperativa.

De esta forma, se renunció parcialmente a las ventajas de la forma de producción estatal en escala de distrito y empresa, diseñada para condiciones de suficiencia de recursos por un nuevo sistema de gestión por las bases productivas, potenciando el sentido de responsabilidad sobre los recursos al ser propiedad de los cooperativistas y mayores exigencias de calidad a las labores.

La Figura 3 ilustra sobre la variabilidad del área de las 1006 bases productivas con producción cañera (AZCUBA, 2022AZCUBA: Base de datos sobre composición de bases productivas, Inst. AZCUBA, Dirección de Agrotecnia, Informe técnico, La Habana, Cuba, 2022.). En ella se aprecia que en el 53,5% de las mismas no sobrepasa las 540 ha y en el 87% las 1080 ha, lo que implica una reducción importante respecto al área de los antiguos distritos.

FIGURA 3. Estructura de las unidades productivas según su área agrícola.

En el año 2008 comienza un proceso de recuperación de la agricultura cañera, que incluye la actividad de mecanización, adquiriéndose nuevos equipos para ser operados en la cosecha y otras actividades por las unidades estatales de servicio, entre ellos: cosechadoras más productivas modelos Case 7000, 7700 y posteriormente 8800, junto a camiones y remolques con 20 t de capacidad de carga y tractores de alta potencia e implementos agrícolas modernos.

Ello resultó en la creación de un nuevo sistema de cosecha y la formación de pelotones de maquinaria para actividades de labranza y atenciones culturales. No obstante, la capacidad de servicios creada con las nuevas cosechadoras cubría solo cerca del 50% de las necesidades, debiendo coexistir el nuevo sistema con el antiguo, formado por los numerosos pelotones de cosechadoras obsoletas modelo KTP2M con muy baja productividad, que pasaron a ser gestionados por las bases productivas al fragmentarse los distritos, con un horizonte de área para la programación de corte muy estrecho, limitado a los campos que no se cosechan con el sistema moderno, en el entorno de la unidad cooperativa que los opera. Ello dificulta realizar durante toda la campaña una planificación de oportunidad, donde coincida el uso de las cosechadoras con el momento óptimo para ejecutar los procesos.

Ejemplo de la dispersión de recursos originada por la eliminación de los distritos es que en la zafra de 2020 a 2021 se programó la operación de 481 pelotones de KTP2M, de ellos 85 con una sola máquina y 340 con dos (AZCUBA, 2021aAZCUBA: Balance de maquinaria para la zafra 2021 a 2022, Inst. AZCUBA, Dirección de mecanización, 2021a.). Esto no solo conlleva a dificultades de planificación, junto a ello se dificulta la asistencia técnica y el suministro de piezas e insumos, además de afectarse la gestión del transporte.

La falta de renovación de la maquinaria de las bases productivas hace a estas dependientes en extremo de las unidades de servicios, situación que debe cambiar al menos en las atenciones culturales, donde existe preferencia de las bases productivas para realizarlas con recursos propios (CNCA-AZCUBA, 2020CNCA-AZCUBA: Diagnóstico técnico de la mecanización agrícola de la base productiva en el Central Cinco de Septiembre, Inst. AZCUBA, Informe técnico, La Habana, Cuba, 25 p., 2020.). Para ello, paulatinamente se dota a las misma de tractores de mediana potencia modelo Belarus 1025 y de nuevos implementos, como el cultivador fertilizador AZ301 (Figura 4), que realiza simultáneamente la fertilización y el cultivo tradicional y a diferencia de los implementos utilizados hasta el momento por esas bases, tienen un elevado pasamiento entre los rastrojos de la caña recién cosechada. No obstante, lo reducido de las áreas de la mayoría de las CPA y UBPC^†††CPA - cooperativa de producción agropecuaria; UBPC - Unidad básica de producción cooperativa. En la CPA los agricultores son propietarios de la tierra, en la UBPC - usufructuarios. hace inefectiva económicamente la organización de pelotones para la realización de labores además de la cosecha e impide aprovechar las ventajas que estos representan para el control de los trabajos, la asistencia técnica de los equipos, atención logística y protección de la maquinaria.

FIGURA 4. Fertilizador AZ301.

Por otra parte, el ritmo de entrega de área cosechada por los pelotones de cosechadoras KTP2M es muy bajo e inferior a la productividad en la jornada de los equipos de cultivo, por lo que se afecta la organización de aquellas actividades de cultivo que deben realizarse inmediatamente después de la cosecha, con independencia a la capacidad de los equipos para evitar atoros con residuos de esa operación.

El objetivo principal de este estudio consiste en fundamentar frentes de trabajo que integren los pelotones de cosecha y otros equipos y recursos de dos o más bases productivas que incluyan las siguientes tareas:

Cosechar de conjunto el área de las unidades integradas en el frente, logrando mediante el incremento del área, acompañado por una adecuada estrategia varietal y de plantación, aumentar el número de opciones para lograr cosechar con una mayor madurez de la caña.
Incrementar el rendimiento de las cosechadoras y reducir los gastos en cosecha a partir un mejor uso del transporte, junto a mayores disponibilidad y seguridad técnica, partiendo de que la concentración de maquinaria facilita la asistencia técnica y abasto de piezas e insumos.
Integrar al frente las actividades de atenciones culturales que corresponde realizar simultáneamente con la cosecha o inmediatamente después, que incluyen:”
La aplicación de herbicidas hormonales mediante el método de “cosecho y aplico”, que consiste en instalar un mecanismo aspersor en la propia cosechadora, con la particularidad de que los herbicidas se depositan sobre el suelo cuando los residuos agrícolas no se han incorporado.
1. La fertilización y el primer cultivo, considerando que la introducción del cultivador fertilizador AZ301 con elevado pasamiento y el incremento de productividad del conjunto de máquinas producto de la integración de pelotones, crea condiciones para ello.

En este trabajo no se profundiza en la tercera tarea dado a que:

El método o sistema “cosecho y aplico” es una tecnología ya evaluada como efectiva y se encuentra en proceso de generalización, cuya presencia en un frente de trabajo está plenamente justificada.
El cultivo y fertilización inmediatamente después de la cosecha está fundamentado agronómicamente por diferentes autores (Martín et al., 1987MARTÍN, O.J.; GÁLVEZ, R.G.; DE ARMAS, U.R.; ESPINOSA, O.R.; VIGOA, H.R.; LEÓN, M.A.: La Caña de Azúcar en Cuba, Ed. Editorial del Ministerio de Cultura, primera ed., La Habana, Cuba, 612 p., 1987.; MINAZ- Cuba, 2000MINAZ- CUBA: Fundamentos Técnicos Prácticos del Cultivo de la Caña de Azúcar, Inst. Ministerio de la Industria Azucarera (MINAZ). Organismo central, La Habana, Cuba, 21 p., 2000.; Santana et al., 2014SANTANA, I.; GONZÁLEZ, M.; CRESPO, R.; GUILLEN, S.: Instructivo técnico para el manejo de la caña de azúcar, Ed. INICA, La Habana, Cuba, 302 p., 2014.), las razones técnicas que impedían su aplicación en esas condiciones se eliminan con la formación de los frentes e introducción del cultivador fertilizador de alto pasamiento AZ301. Las innovaciones constructivas que caracterizan al mismo serán objeto de otros trabajos.

Equipo	Frente 1 - Antero Regalado+Regadío	Testigo 1. Vietnam	Testigo 2. CPA 21 de Septiembre	Frente 2. - Desquite + R. Octubre	Frente 3. - Victoria + Chapeo
Cosechadoras KTP2M	5	3	2	5	5
Camiones	10	5	2	7	9
Remolques de camión	10	5	3	7	9
tractores movedores	2	2	1	2	3
tarea de corte diaria	500 t	500 t	140 t	380 t	520 t

Equipo

Frente 1 - Antero Regalado+Regadío

Testigo 1. Vietnam

Testigo 2. CPA 21 de Septiembre

Frente 2. - Desquite + R. Octubre

Frente 3. - Victoria + Chapeo

Cosechadoras KTP2M

Camiones

Remolques de camión

tractores movedores

tarea de corte diaria

500 t

140 t

380 t

520 t

Parámetro evaluado	Frentes y testigos
masa cosechada en ciclo de estudio (t)	14881,7	7596,12	15230
Horas perdidas por transporte	398:57:12	225:50:12	286:30:00
Relación tiempo perdido por transporte/ masa cosechada	0:01:37	0:01:47	0:01:08
Ventaja porcentual	9,83%	---	36,73%

Parámetro evaluado

Frentes y testigos

A. Regalado + Regadío (F1)

Vietnam (T1)

Victoria + Chapeo (F3)

masa cosechada en ciclo de estudio (t)

14881,7

7596,12

15230

Horas perdidas por transporte

398:57:12

225:50:12

286:30:00

Relación tiempo perdido por transporte/ masa cosechada

0:01:37

0:01:47

0:01:08

Ventaja porcentual

9,83%

---

36,73%

^{^†}	Pelotón -grupo especializado de personal, máquinas agrícolas y medios de asistencia técnica que trabajan con una misma ubicación, objetivo y dirección.
^{^††}	Caña neta - caña sin materias extrañas.
^{^†††}	CPA - cooperativa de producción agropecuaria; UBPC - Unidad básica de producción cooperativa. En la CPA los agricultores son propietarios de la tierra, en la UBPC - usufructuarios.
^{^††††}	En una base productiva fundamentalmente cooperativa los frentes se forman por unión de máquinas de diferentes cooperativas bajos las condiciones que ellos acuerdan y con uso común de los transportes de caña, para así coincidir en las áreas con mayor madurez de caña definidas en el plan de la empresa. Un nivel superior de frente surge cuando las partes convienen en lograr ahorros, mediante la reducción de otros medios y equipos dando uso común a los existentes.

Machinery labor fronts. A contribution to management of mechanization in sugarcane production bases

INTRODUCTION

Theoretical and methodological fundaments

The front as a facilitator of increased operational effectiveness

Evaluation methodology

RESULT AND DISCUSSION

CONCLUSIONS

NOTES

REFERENCES

Frentes de trabajo. Una contribución a la gestión de mecanización en las bases productivas cañeras

INTRODUCCIÓN

MATERIALES Y MÉTODOS

Fundamentos Teóricos y Metodológicos

El frente como facilitador del incremento de la eficacia operativa

Metodología de evaluación

RESULTADO Y DISCUSIÓN

CONCLUSIONES

NOTAS

^{^†}	Platoon - specialized group of personnel, agricultural machines and technical assistance means that work with the same location, objective and direction.
^{^††}	Net cane - cane without foreign matter.
^{^†††}	CPA - agricultural production cooperative; UBPC - Basic unit of cooperative production. In the CPA, farmers are owners of the land, in the UBPC - usufructuaries.
^{^††††}	In a fundamentally cooperative productive base, the fronts are formed by the union of machines from different cooperatives under the conditions that they agree upon and with common use of cane transport, in order to coincide in the areas with greater sugar cane maturity defined in the plan of the company. A higher level of front arises when the parties agree to achieve savings, by reducing other means and equipment by giving common use to existing ones.