Benefits of the gearbox in the distribution of fertilizers and seeds

The appropriate use of the volumes of fertilizers and seeds applied to crops has been constantly studied and disseminated by technicians and specialists in planning the implementation of the main agricultural crops cultivated. This article refers to the characteristics of the traditional gear transmission system and presents innovative solutions for distributing fertilizers and seeds, components that speed up the adjustment work and provide more viability to fertilization and seeding systems at variable rates.

Current implements, such as seeders, planters and fertilizer distributors, have used, since the beginning of their development, the use of gear combinations to increase or decrease the rotation of the axes that act on the fertilizer or seed distributors, thereby increasing or decreasing the quantity of the input distributed in the area.

When the producer needs to vary the volume of these inputs, it is necessary to change gears. Many manufacturers use the so-called “gear rack” to facilitate the exchange of these combinations and reach the desired input volume.

It is very common in practice for the producer to use “approximate” doses, varying from around 10kg to 25kg of fertilizers per hectare and from two to three seeds per linear meter. This variation generally compromises the planning carried out prior to planting, as the producer generally has to acquire more inputs during planting or make planning changes due to the “inaccuracy” of the equipment. Much of this variation is also due to the quality and variability of fertilizers, granulometry characteristics, hygroscopicity and the climate at the time of application directly affect the volume distributed.

Another difficulty encountered by the producer is how to adjust and check the desired volume of inputs. The most accurate methods require the producer to walk with the implement for a known distance or simulate this movement by turning the implement's wheel, collecting and weighing the inputs until reaching a dosage close to the desired one. This process is laborious and takes time, around an hour to adjust and check the implement, so the producer is limited to doing it once or twice during planting or just checking the adjustment of the seeds when there is a change of cultivar.

Recently, a new tool emerged to help eliminate variation problems and speed up the regulation of fertilizer and seed distribution: the gearbox. This component replaces the need to change gears to determine the rotation speed of the fertilizer or seed distributor shaft.

Adaptable to all implements and developed for the torque characteristics of Brazilian machines, the box is installed on the implement and has its input rotation activated by the movement of the wheel during operation. The box's output shaft is connected to the shaft that drives the fertilizer or seed distributors and its rotation is precisely determined by the positioning of the regulator according to the desired quantity of input to be distributed.

This component allows the producer to adjust the fertilizer distribution with a variation of approximately 1kg in 1kg per hectare and adjust between 0,1 and 0,3 seeds per linear meter.

In addition to the incomparable precision of the gear system, another great advantage of this component is the agility in regulating and measuring the desired input volumes. With the aid of a crank and an exclusive ratchet system on the input shaft of the box, it is possible to simulate the displacement by rotating the mechanism with the implement stopped and collecting the inputs for later weighing or counting, to increase or decrease the quantity of the input. it is only necessary to activate a handle by turning it in the desired direction, without having to touch chains or gears.

The planting period or “window” has been shown to be an important factor limiting productive potential, with more and more agility and planting at the best times depending on each region, which is why it is very common for most producers not to check the adjustment of implements periodically. during planting. With this equipment, measuring the adjustment takes around five minutes and can be done more frequently, allowing the differences between planning and execution in practice to be minimized.

Among the factors that lead to variability in fertilizer distribution, the most common are variation in granulometry, segregation of granules, wear of distributing screws, lack of maintenance, time of use of the implement, among others. All of these factors can be minimized if the quality standards of inputs and equipment are respected, however, a factor that directly affects this variability is the weather condition at the time of the operation. Long periods of high humidity directly interfere with the fertilizer doser's ability to distribute a homogeneous amount of input, especially fertilizers with high hygroscopicity, resulting in a decrease in the distributed volume. Periods of low humidity generally result in better fluidity of the fertilizer and generally present an increase in volume in relation to what is desired. That is why it is important to have a tool that provides more ease and allows quick decisions to be made to adjust volumes according to weather conditions.

In relation to seed distribution and especially the establishment of the desired population per area, there are numerous times when the producer needs to make adjustments according to the climate and soil conditions. The inaccuracy often caused by the lack of adjustments to the details of characteristics such as soil moisture and the type of cover or “mulch” can significantly affect the establishment of the desired plant population.

In practice, no one other than the producer or technician, at the time of planting, knows when they would need to increase or decrease one or two seeds per meter, or in a known part of a field, increase the fertilizer, however, they end up not doing it because it is too laborious. , and with the gear system it will not be able to achieve the desired adjustment accurately.

This “variable precision" is the biggest challenge sought by technicians and manufacturers, being able to distribute only what is necessary for each area or soil characteristics in which the crop is being established with prior study and planning. The use of variable rates of fertilizers and seeds allows so that the producer can put into practice the knowledge of the area’s history.

The variable rate systems implemented in current implements use hydraulics as a source for generating the rotations of the axles of fertilizer or seed distributors. It is a functional system, however, limited in practice, it has problems with oil heating and tractor power consumption, which makes it impossible due to the cost of components to solve these problems and is inaccessible for small implements.

As an alternative to the hydraulic variable rate, there is the electromechanical variable rate, which is the activation of the mechanical variator box automatically by an electric motor, a much more viable system that is simple to install. The driving force continues to be the implement's rotation during displacement and the rotation speed is controlled by the action of an automatic regulator that allows variation as programmed, this allows the producer to achieve a new reality of precision.

The vast majority of producers or technicians directly associate the term “precision agriculture” with the use of GPS equipment. This equipment has greatly facilitated the work of locating and integrating systems that enable the use of variable rates of fertilization and soil correction, as well as the establishment of plants through predefined maps in planning. The electromechanical variable rate system allows even without GPS, at a certain known or demarcated point, the operator himself can select the desired dose on the monitor during the planting operation. electric motor only operates for the time necessary to make the actuation from the maximum point to the minimum of the regulator, in a time of two seconds, the mechanism provides a variation of fertilizers between 800 and 1.000kg/ha up to 0kg/ha and to vary a dose of 100kg/ha, the distance covered will be less than two linear meters in a planting operation at a speed of 8km/h.

With the complete system, including GPS, planning based on knowledge of all the characteristics of the areas becomes viable. The producer can program each plot containing the volume of fertilizer and the desired seed population through the software or even on the monitor and begin the planting operation. The mechanism regulates itself automatically and to measure the distributed volumes, the mechanism provides a very agile system.

The practical implementation of the mechanism in seeders, planters and other distributors involves a simple adaptation process, simply by replacing the gear system and positioning the box in a location that has access to the distributor and wheelset axles. To install the variable rate, simply connect the cabling to the power source, install the monitor in the implement cabin and position the GPS.

Similar tools equip the vast majority of implements used in Europe and the United States, some national manufacturers have similar mechanisms that they use for export, and in national machines there are already projects to implement this technology. It is another tool available to facilitate work in the field and provide more precision in the implementation of agricultural crop planning.

This article was published in issue 140 of Cultivar Máquinas magazine. Click here to read the edition.