INCLUDE TABLE 3
To mitigate the impact of soil losses due to water erosion and
contribute to SOC sequestration and mitigation of GHG’s emission, Brazil
has adopted public policies and national and regional plans to achieve
high productivity and the intensification of agricultural activity, with
a significative improvement of environmental quality. The main policies
and plans with the projections of results are summarized below:
- Recovery and agricultural intensification in degraded lands, where
annual crops are cultivated with adoption of practices and
technologies based on the principles of ZT/CA, iLCF-CA and other mixed
systems. These actions have the potential of promoting the mitigation
of, at least, 90% of the soil losses in 22.8 million ha of croplands.
- Adoption of best management practices (BMPs) based on ZT/CA in 9.2
million ha with sugarcane production, including the rotation with
cover crops (ex. crotalaria), grains (soybean, corn), or grasses
(Brachiaria) in the renewal of sugarcane plantations. The mitigation
of soil losses is estimated in more than 50% during renewal and
re-installation of sugarcane plantations.
- Incentive to the recovery and reinsertion of about 64 million hectares
of rangelands with some level of degradation, including highly
degraded lands (formation of ravines and gullies) and severe loss of
animal support capacity, according to the potential agricultural
capability, through the establishment of national and regional plans.
The ABC plan (Andrade & Freitas, 2019) prognoses is that more than
70% of the degraded rangelands in Brazil will be recovered or changed
into croplands by 2030.
- Afforestation and reforestation, mainly with species of economic value
and with silvopastoral systems, derived from iCLF-CA, planned for more
than 60 million ha of areas reserved for the protection of natural
vegetation, according to Brazilian legislation, considering 30% of
the environmental protection areas, 50% of Indian reserves and
settlement areas and 30% of the quilombola areas.
The effect of the plans and policies above in terms of potential of
annual SOC sequestration in lands with different use and coverage was
calculated using the parameters suggested by Lal et al. (2018) in a
perspective of 50 years (Table 3). BMPs with ZT/CA and iCLF-CA involve
integrating all the individual agricultural practices and technologies
available to guarantee erosion control and to produce annual biomass in
a sustainable and competitive manner (Freitas et al., 2000). The
estimates point for a total value of annual soil C sequestration varying
from 44.63 to 145.95 million tons (Table 4), where the maximum values
are in the degraded pastures followed by lands for settlements and
annual crops.