4.1 Land Use and Occupation
The following crops predominate in this stretch of Watershed: Pasture,
Natural Forest and Coffee. The natural forest, considered the best
vegetation cover, is present in an area corresponding to 21.16% of the
area of this stretch of Rio do Peixe Watershed. Santos et al. (2014)
evaluating a watershed with 11 thousand ha, located in Botucatu, SP, in
relief conditions similar to Rio do Peixe watershed, in terms of land
use and occupation found 1,109 ha of natural forest, corresponding to
9.95% of the watershed area, a situation that corresponds to less than
half of the result found in the present study, showing that in this
stretch of Rio do Peixe Watershed, the forest is more preserved. The
last decades have been characterized by drastic changes in land use and
occupation in the region, which for Zalidis et al. (2002) represented
one of the main driving forces for environmental degradation, especially
on soil and water.
As for the pasture area, there is an occupation in the studied section
of 30,472 ha, representing 60.81% of the total area of the Watershed
(Table 2). The results found are similar to those of Lima et al. (2004)
who evaluated 43,228 ha of pasture area in a watershed in Ilha Solteira,
which represents 66.79% of the total area. In the present study, one of
the positive examples was the transformation of a property, which used
to operate livestock, located in Ocauçu, SP, with a degraded pasture
area of 500 ha. After carrying out the present study, these 500 ha were
transformed into an agricultural area with the no-tillage system,
intended for annual cycle crops, with rotation: brachiaria straw,
soybeans, corn and wheat in winter (crop change and soil management). A
new conservationist technology that was implemented in the region.
Using the images from the Google Earth® Pro to verify the effectiveness
of the works implanted in the area occupied with pasture with the
presence of erosive processes (Figure 2A and 2B), the action of
agri-environmental adequacy to contain the erosive processes was
implemented and the control of the erosion in the area was accomplished
with the construction of containment boxes on areas with pastures. There
was an improvement in the visual aspect of the area comparing to soil
conservation, in which case it was proven that pasture management with
the use of hydraulic structures (containment boxes) favored the
restoration of the area and the return of potential soil productivity.
Analysing Figures 2C, 2D, 2L and 2M, it can be seen that the change in
management in coffee culture provided a positive change in the
landscape, inferring that in addition to improving the landscape with
more intense vegetation cover (Figures 2D and 2M), there was an
improvement in potential crop productivity. In the coffee culture, what
contributed to the improvement of the soil conditions was the adequacy
of the crop following the level of the ground and recovery of soil
fertility. The soil conservation techniques applied in this case were
sufficient to control erosive processes. In Figures 2E and 2G, using the
image comparison method, it can be seen that the agricultural terracing
built in the area in question was efficient in controlling erosion
processes at the property. According to Araújo et al. (2009) the use of
appropriate management measures and erosion mitigating actions, with the
recovery of the impacted areas, there will be an improvement in water
quality and control of sediment production, minimizing silting and
consequently, there will be an almost complete environmental
rehabilitation. The comparison between aerial images from before (T1)
and after (T2) was used to assess the efficiency of the results
obtained, a method that was also used by Bezerra et al. (2012) who
evaluated by photocomparation the vegetation cover and the potential of
water in the soil aiming at the monitoring and recovery of degraded
areas in Uberlândia, MG, and considered that the photocomparation with
the supervised classification allowed to follow the development of the
vegetation cover with grasses, as well as their relation to soil water
potential. According to Menezes et al. (2009) with remote sensing, it
was possible to verify the presence of areas already affected by
inadequate management on areas with degraded pastures. These authors
also highlighted the fact that native vegetation has been largely
converted into pasture. Figures 2K and 2O, conversely, show the
mechanical control of erosions with the construction of dams and
terraces that altered the landscape of the place, previously degraded,
into a pasture with productive capacity (Figures 2J and 2N). Figure 2J
shows an old and eroded road that carried sediments to the bed of Rio do
Peixe and which was corrected by building terraces (Figure 2K). It is
important to observe the fact that there are practices focused on the
conservation, which represents a large part of the Rio do Peixe
Watershed section, besides promoting important benefits for soil
conservation, it can be another factor that stimulates the increase in
income for producers, once, with conserved pasture, there is a higher
volume of biomass and, consequently, the possibility of higher animal
density. An example of this statement is the pasture areas recovered
with the adoption of the Integrated Crop-Livestock Systems (LIS), where
the management of these pastures has changed, replacing the grass
variety and providing pasture with good vegetal mass during the dry
periods. This resulted in an occupancy rate of five Animal Units (AUs)
per ha, as evidenced by the evaluation of 14 properties, wherein 10 of
them, there was an average growth of 31% in the occupancy rate,
compared to the original situation found before carrying out the
inspection work. It corroborates with this information the study of
Albernaz & Lima (2007) who evaluated two sub-watersheds, in Lavras, MG,
occupied by pastures, according to conservationist practices: level
planting, terracing, catchment basins, liming maintenance and inferred
that at Ribeirão Santa Cruz sub-watershed (SW) more conservation
practices are adopted than at SW Água Limpa and the exposure of the soil
to degradation was bigger at SW Água Limpa. A similar result was
observed by Zolin et al. (2011) stating that the biggest relative
reductions in soil loss occurred on scenarios with conserved pasture,
indicating that the optimization of soil conservation can be
accomplished by adopting conservationist management practices for
pasture recovery. According to Rodrigues et al. (2015) who analysed the
role of vegetation in water interception and erosion control, at Rio
Paraíso Watershed, in São Manuel, SP, the uncovered soil showed a
98.09% increase in sediment production, when compared to soils with
vegetation cover.
This study to inspect the use and conservation of the soil is important
not only for the soil and water preservation, however, also for the
rural producer to earn more money with his activity, a fact that can be
proven by analysing Table 3, wherein most of the agricultural properties
worked with the recovery of pastures, farmers had an increase of 31% in
the occupation rates of these areas and with this, they will have a
higher income and a greater profit in their activity.