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Soil compaction due to agricultural machinery traffic is a threat to soil productivity and soil ecological functions. The prediction of soil stresses and compaction that soil bear during the harvest and transport are fundamental indications in the prevention strategies and remediation of the soil compaction. The objective of this research was to predict soil compaction caused by harvesters and transport equipment during sugarcane harvest on soft soil. Machinery traffic was simulated using the TASC V3.0 model, Module 1 "Stress Propagation and Soil Damage" was used. The machine system used for harvest sugarcane were formed by harvesters CASE IH 8800, and tipping tows 7CX (SC)-10 pulling by tractors YTO 1608 or XTZ 150K-09. Parameters from machinery and soil are introducing as data. The use of modelling TASC V3.0 permitted to predict soil compaction caused by harvesters and transport equipment during sugarcane harvest on soft soil. More severe soil compaction was obtained during use of tipping tow 7CX (SC)-10 due to high mean contact pressure and high tire load, which caused severe soil compaction until a depth of 0.37 m. Rear tire of tractor YTO 1604 caused severe soil compaction too reaching 0.31 m of depth. In general sense all equipment caused severe soil compaction in tillage layer, therefore must be make decompactions works with the objective to loose soil in depth for a good developed of sugarcane ratoons. [ABSTRACT FROM AUTHOR]

The objective of the present work was to find the relationship between uniformity of irrigation flow and agro-climatic factors with the yield, during pepper growing in greenhouse. The study was carried out in brown soil with carbonates, in a module of three greenhouses, Granma-1 Model, placed at "Valle del Yabú" Agricultural Company, in Villa Clara Province. In each greenhouse, six soil beds were formed with three irrigation branches with non-compensating Twin Drip drippers. For the study, 27 sampling points were taken, evenly distributed in the three greenhouses. The wind speed, temperature and relative humidity were measured with the Kestrel 5000 micro weather station. For the sampling of dripper flow, rain gauges were located at each experimental point and the irrigation coefficient of uniformity was determined. As a result, wind speed, relative humidity and temperature, inside the greenhouse, showed spatial variability values that satisfy the crop requirements. The coefficient of uniformity of irrigation rate was considered as acceptable with value of 71.2%, as a consequence of the obstruction of drippers, denoting a wide variability of irrigation rate without the presence of water flood or dry soil. [ABSTRACT FROM AUTHOR]

In the present work, the vegetation indices obtained from satellite images are used to monitoring sugarcane crop. The study was carried out in 5,5 ha of sugarcane field, planted with CP 52-43 variety located in Camajuaní Municipality, Cuba. Vegetative evolution of the plantation was monitored by field measurements of leaf width, stem diameter, stem height, soil moisture and vegetal cover, using the diagonal distribution method for samples collection. The services available in Earth Observed System (EOS) were used to obtain images of vegetative index of: NDVI, SAVI, EVI and NDWI. The initial stage of crop was characterized by low values of soil moisture and foliar development of sugarcane plants, EVI and NDVI indices showed results according to the low vegetative development with values between 0,2 and 0,4, while NDWI agreed with dry soil. In the rainy season, after the fourth month of the plantation, an increase in soil moisture to 42,9% took place, the plants' biophysics parameters: stem height, stem diameter and leaf width also increased, EVI index reached between 0,6 and 0,8 in 74,4% crop area and in the same way NDVI index showed values between 0,7 to 0,8. However, NDWI index showed values between -1 and -0.6 belonging to dry soil, no matching with the actual moisture conditions. Through monitoring with Sentinel-2 satellite, a more stable representation of the increase in vegetation was achieved, as well as more adequate values of the initial and final state of the crop were obtained. [ABSTRACT FROM AUTHOR]

The present work is focused on the effects on the soil due to the traffic of sugarcane harvesting machines. The investigation took place in areas of three different units of sugarcane production in the UEB "Héctor Rodríguez", located on the north coast of Villa Clara. The CASE IH 8 800 harvesting machine and self-dumping car pulled by the Maxxum CASE 150 tractor were used for the study. The main characteristics of the predominant soils were determined, as well as the variations of soil micro relief, the bulk density and the soil moisture. The results showed soil modifications due to the traffic of the equipment during the harvest, highlighting the effect of the tractor and self-balancing aggregate. The machines introduce considerably modifications in field profile, by moving over and through the furrow, affecting the root zone. Dry bulk density values characteristic of heavy clay soils, were found, increasing this value after the harvesting machinery passing. On the other hand, soil moisture of 64.0% became in serious traffic problems for tractor self-balancing aggregates and causing traffic jam. [ABSTRACT FROM AUTHOR]

The objective of the present work, was to determine the main effects on the soil and in the sugar cane stumps, of mechanized activities in the plantations. It was carried out in the Basic Unit of Cooperative Production (UBPC) Máximo Gómez, belonging to the municipality of Camajuaní, Villa Clara. To carry out the research, a characterization of the study area was made; the variations of the furrow profile were determined; resistance to penetration and soil moisture in the root zone and in the street, also damage to the cane strain was identified. The main results showed agglomerations of residues from the previous harvest and clean spaces without stumps and new sprout. The resistance to soil penetration showed values of 0.8 and 1.2 kPa on surface of the street and the area of the stumps respectively, increasing with the depth of the soil up to 30 cm. Soil moisture in the stumps was higher than in the street up to 25 cm deep, with values of 28.6 and 30% respectively on the surface. For its part, the profile of the furrows showed a considerable variability in regarding the geometry and height of the ridges. Limitations were found in terms of the depth of the main roots, their vitality and quantity, the secondary or capillary roots showed low development. [ABSTRACT FROM AUTHOR]

Determination of the factors that change the energy consumption for irrigation with Pivot electric power machines, was carried out in the “Valle del Yabú" Agricultural Company. By using as a case study aWestern brand irrigation machine, with four towers and a irrigated area of 18.2 ha, hydropower of 1.35 L/s/ha, flow rate of 23.45 L/s and an efficiency of 85% according to the manufacturer. The study was performed during irrigation activity in potato cultivation. During theinvestigation, an evaluation of the irrigation machine was carried out in terms of the parameters of design, assembly and operation. Energy consumption was determined independently of the pumping systemand the irrigation machine. The total electrical energy consumption of the system was 9 039.05 kWh, for a specific consumption per cubic meters of pumped water of 0.13 kWh. From the analysis done to the irrigation schedule used, a tendency was identified for over-irrigation with advanced and insufficient irrigation activities. Likewise, the coefficient of irrigation uniformity was obtained in 78%, which favors the irregular water deposit and the need for corrective activities and therefore, the increase of energy expenditure. Costs for this type of activity accounted for 9.72% of the total production costs. [ABSTRACT FROM AUTHOR]

The goal of the present work was to determine the main properties of a compost made from bagasse, slowness and ash, obtained from the sugar factory process. To elaborate the mixture a characterization of the raw material was carried out in function of the properties related to the composting process. During the process of anaerobic biodigestion, the control of the main monitoring parameters was carried out, until reaching the maturation state. In the raw material used a bulk density of 0.12 to 0.48 g cm-3 was found, the pH oscillated between 5.2 and 8.7, while the electrical conductivity was in the range of 0,4 to 0,9 S m-1. On the other hand, the contents of P, K, Ca and Mg showed values between 0.3 and 2.8 %. Finally, a bulk density of 0.5 g cm-3 was obtained in the compost. The carbon-nitrogen (C/N) ratio, showed a linear relation with respect to the time of composting, showing a suitable maturation of the mixture. The presence of N, P, K, Ca and Mg with values of 1; 1.3; 1.1; 2 and 1.1 % were also verified. After evaluating the results it is concluded that compost shows a suitable composition to be used as organic fertilizer in agriculture. [ABSTRACT FROM AUTHOR]

Discrete Element Method (DEM) was used to simulate the soil-tool interaction. The model is based on the action of normal, shear, cohesion and friction forces into the cohesive granular medium, calculated as a function of micro-mechanical properties. Macro-mechanical properties of soil-soil and soil-metal were used to determining the micro parameters on the model. In order simulate the tillage operations a soil virtual block was generated in hexagonal compacted array using 45 000 spherical particles forming a cohesive block. A soil-bin installation was conditioned to measuring the draft force in hard-dry and soft-wet soil condition to compare the results with simulation tests. The comparison showed a small under predicted behavior of the model for soft-wet soil; however the results become more accurate toward hard-dry soil conditions. The density changes during simulations and pressures distributions below the tillage tool path is showed, given a dynamic representation of soil internal tension and loosening after tillage operation. [ABSTRACT FROM AUTHOR]

Specific information about physical-mechanical properties of soil is a support for simulation by computation techniques as Finite Element and Discrete Element methods to predict the soil behavior during soil tool interaction. Determination of basics mechanical properties needed for mathematical modeling of clay soils on the arable layer were carried out using triaxial compression and modified shear box test. Variations in shear strength, Yong's modulus, internal friction angle, soil-metal friction angle, cohesion and adhesion were determined at different experimental levels of gravimetric water content and soil dry bulk density. Multi-factorial regression analysis to estimate the corresponding values of above properties was performed resulting on statistical prediction equations for all basic mechanical properties under study. [ABSTRACT FROM AUTHOR]

The work was carried out in the Valle del Yabú Agricultural Company located in the municipality of Santa Clara, Villa Clara province with the objective of determining the efficiency in the use of irrigation water, in the aforementioned company, through the calculation of the productivity of the water applied to some crops of economic importance. The productivity of the water applied by irrigation, the productivity of the total water, and the total water applied (T), in the corn, potato, dasheen, beans and sweet potato crops were calculated. In the sweet potato the productivity of water applied by irrigation, 20 kg / m3, was higher than that of the rest of the crops. In the potato the average was 7.74 kg / m3, in the bean it reached values of 4.74 kg / m3, in the case of the dasheen it was 3.92 kg / m3 and the corn was 10.66 kg / m3 The results showed a low productivity and inefficiency in the use of water for potato, bean and corn crops, not the case of dasheen and sweet potato where water productivity values were obtained that show an efficient use of water in these crops. [ABSTRACT FROM AUTHOR]

The unavailability of chemical fertilizers to obtain high yields in Cuban agriculture has led to the development of other organ-mineral fertilizers, such as Agromena - G, produced by the Empresa Geominera del Centro in Villa Clara. The objective of this work was to characterize the organ-mineral fertilizer Agromena - G, based on the determination of the main physical and chemical properties of the fertilizer for its mechanized application in the improvement of soils and the increasing of crops yield. The methodology included the determination of physical properties as granulometry, apparent density and humidity of the organ-mineral fertilizer. In addition, chemical properties such as pH, electrical conductivity, available phosphorus and organic matter were determined. The physical properties of the organ-mineral fertilizer Agromena - G, show that its granulometry (approximately 50% of the grains smaller than 1 mm) favors its use since it facilitates its acquisition by the plants. The other determined properties behave within acceptable values for the most common granular fertilizers. The physical properties of this fertilizer favor its mechanized application both by broadcast fertilizing machines and with machines for localized fertilization. The chemical properties of this organ-mineral fertilizer demonstrated its potential use as an alternative for managing plant nutrition although it is recommended the surveillance of indicators as electrical conductivity and cations concentrations, especially Na+, in clayed soils susceptible to salinity problems. [ABSTRACT FROM AUTHOR]

The unavailability of chemical fertilizers to obtain high yields in Cuban agriculture has led to the development of other organic mineral fertilizers, such as Agromena - G, produced by Empresa Geominera del Centro in Villa Clara. The objective of this work was to characterize the ID-David fertilizer for the mechanized application of the Agromena - G organic mineral fertilizer produced by Empresa Geominera del Centro. The methodology included the determination of the uniformity of the transverse distribution of the fertilizer and the general characterization of the work of the fertilizer spreader. The characterization of the ID-David fertilizer spreader, fertilizer locator trailer, during the application of the Agromena - G organic mineral fertilizer showed that this machine performs reliable and stable work. The uniformity of the fertilizer application had a coefficient of variation of 15.29%, which is considered adequate for the distribution of fertilizers with high delivery doses. [ABSTRACT FROM AUTHOR]

Tyre traffic over soil causes non-uniform ground pressures across the tyre width and along the soil–tyre contact area. The objective of this paper was to obtain in the topsoil the shape, magnitudes, distribution and transmission in depth of the ground pressures from a finite element model of soil compaction. The influence of tyre inflation pressure, tyre load and soil water content over the pressures propagation in the soil was analysed. The model shows how to low inflation pressure the tyre carcass supports most of the total load and the biggest peak pressures are distributed in the tyre axes when it traffics over firm soil. For high inflation pressure the incremented stiff causes that pressure is distributed with parabolic shape. In wet soil the inflation pressure does not influence on the ground pressure distribution, this depends only on the tyre load. The inflation pressure and tyre load changed the shape of the vertical pressures distribution on the surface of a hard dry soil, but these variables did not affect the distribution of vertical stresses in a soft wet soil or below a depth of 0.15 m. [ABSTRACT FROM AUTHOR]

The research approaches the main properties of the coffee (coffea canephora) of the variety robusta, the one which is planted in the region of the state Trujillo, Venezuela. The objective was the determination of the physical and mechanical properties of the fruits and of the system fruit pedunclepedicelum, being an indispensable stage during the researches related with the mechanized crop in two maturation stages. In this paper are showed the results on the determination of a group of dimensional and elastic properties, and also was determined the rigidity, Module of Young and coefficient of Poisson of the system fruit-peduncle-pedicelum. The results showed the main characteristics of the plantations and the bushes of the area in study as well as the agro-climatic variables. Also in the controlled dimensions of the fruits was observed symmetry in all the results, being adjusted to a normal distribution. On the other hand were determined the values and the moment required for the detachment of the fruits and the forms in that the detachment takes place. [ABSTRACT FROM AUTHOR]

The development of agricultural production requires the use of machinery to increase productivity and quality of work, a problem that is becoming more pressing in short-cycle crops (corn and beans), creating two possible scenarios, the acquisition of machinery or the improvement of the existing ones. On this last scenario, in recent years, the Ministry of Agriculture of Cuba (MINAG) has been projecting. For this reason the present work has as objective to redesign the grain seeder "Guajiro AM 2010-1-5T"for its improvement. To fulfill this objective, the machine was redesigned fundamentally for grain transmission and distribution systems, for which the resistance analysis by the finite element method (MEF) and its operation were made, through the help of the specialized softwaresMechanical Desktop 2008 and SolidWorks 2010. Later, a prototype was built which was tested in static and working conditions during the planting of corn and beans. Finally, the cost sheet was prepared and the economic feasibility of its development was determined. The main results showed that the design variant developed is capable of meeting the requirements of resistance, performance and safety necessary for these machines, in addition to meeting the quality requirements during the planting of beans and corn. The economic analysis showed the feasibility of its improvement, with an economic effectiveness of $14,340.25 (Cuban peso). [ABSTRACT FROM AUTHOR]

Pruning is a very important practice to get good yields from guava tree. The present paper had as objective to examine researches accomplished on the pruning of guava tree and its influence in the yield of this fruit tree. A review was made from the available information on the topic in Cuba and abroad. Previous research evidence increments of guava production with the pruning. However, there is not a clear increasing tendency in the intensity of this practice, because the obtained results were different in terms of the cultivar investigated, plantation density, season and climate. Several authors proposed monthly pruning all the year, as well as, pruning at least three times a year. Regarding the pruning intensity, several authors agree that pruning the end of the branch can be beneficial in terms of fruit production and quality, since severe pruning reduces fruit production. However, other authors recommend the use of severe pruning for obtain higher yield. [ABSTRACT FROM AUTHOR]

This research was conducted with the objective of evaluating the irrigation performance of bean crops in Eutric Cambisol soil conditions. The main parameters related to irrigation scheduling were determined. The water application for the crop and the behavior of climatic variables during the execution of the work were obtained. The results showed that the needs of crop water are satisfied with 14 irrigations, with a total irrigation of 2 517,72 m3 ha-1,which is very similar to that proposed by several authors for crop beans. However, farmers performed 11 irrigations applying a total net irrigation of 4 843, 3 m3 ha-1 consuming 762,4 m3 more of water to produce a ton of bean than the necessary, applying the planning irrigation proposed in this paper. Total net irrigation applied is far superior from obtained by the crop water needs, which brings about low efficiency in water use. [ABSTRACT FROM AUTHOR]

For the explanation of the mechanisms that originate the failure of the soil when it is interacted for a farm tool and the prediction of efforts have been developed more than fifty analytic models, reaching the biggest acceptance those that are based on the theory of the passive pressures of the soil. For such a reason, the present work has as objective to determine the accuracy of four models that are based on the universal equation of the soil movement, during the farming of a Rhodic Ferralsol of the occident of Cuba. Was determined experimentally the resistance of the soil during the tillage under controlled conditions in the channel of soils CS-CEMA-25, and were programmed the sequences of calculation of the models Godwin & Spoor, McKyes & Ali,; Grisso et al., in the software Mathcad 15. The main results showed the limitations of these models to predict with accuracy the efforts that arise during the farming in highly cohesive soils, as well as for tools that differ of the geometry for those which originally were developed. It was also demonstrated that a high correlation (r=0.90 to 0.98) exists among the predicted values for these models, evidencing the likeness in the theoretical approaches that base them. On the other hand was observed that the speed of advance of the working tool has very little incidence in the accuracy of the predictions of the investigated models. [ABSTRACT FROM AUTHOR]

Starting from the development that has reached the computational means in the last decades, the application of the numeric methods in the simulation of the interaction soil tillage-tool, has won in acceptance. As previous step, to the simulation of this phenomenon becomes necessary the definition of the models that predict with more accuracy the soil mechanical behavior. Taking into account these aspects the objective of present work is, to simulate the soil mechanical behavior in the soil-tillage tool interface by means of the finite element method. Starting from the employment of a model that is based on frictional approaches, with the inclusion of the adherence and the establishment of a tension of slip limit, as penalty to restrict the relative displacement between both surfaces. The models were implemented in the computational tool ABAQUS 6.4, starting from that which the soil-metal relative displacement was simulated. The results evidenced the validity of the model implemented to simulate the soil mechanical response in the soil-tool interface. The errors in the prediction of the soil stress oscillated from 1,45 to 5,45%, for the case of the soil vertical deformations it varied among 2,22 to 3,57%. [ABSTRACT FROM AUTHOR]

The constitutive models of critical state are among the most employed for soil compaction simulation by means of finite element method. This paper has the objective to determine the influence of soil bulk density on elastoplastic parameters of Rhodic Ferralsol soil. Triaxial and compression uniaxial tests were carried out to remoulded samples, with a bulk density of 1.1; 1.175; 1.25 Mg m-3, and gravimetric moisture content of 25 kg g-1. The obtained values of variables analyzed can be used as input data to modeling soil compaction by finite element method and allow to know critical state variables behaviour of one of the Cuban soils with major economic importance. [ABSTRACT FROM AUTHOR]