Principles of Soil Management in Neotropical Savannas - Principles of Sustainable Soil Management in Agroecosystems - page 80

3.3 FUTURE TRENDS: LAND USE, RESEARCH,
AND ENVIRONMENT
In 1960, no one would predict that the Cerrado region could produce three crops per
year, or grow soybean varieties totally independent of N fertilizers yet highly pro-
ductive, or would adopt NT systems faster than anywhere else in the world. Indeed,
the mere vision of the small, twisted trees and the highly variable grass strata on
the top of those nutrient-depleted, acidic soils was enough to deem “Cerrado agri-
culture” an oxymoron. By the same token, predicting how agriculture and soil man-
agement will look like in the Cerrado for the next 50 years is perhaps no more than
an educated guess (still much clearer, however, than foreseeing the same for the
Amazon). Nevertheless, it is apparent that some issues will become more and more
important for soil management in the next few decades, which are given as follows.
(1) Climate change . Some climatic models simulate that precipitations by 2020
to 2080 in the Cerrado core area will decrease by ~10%, whereas MAT will
steadily increase by 2°C, in comparison to the 1961-1990 period (Hamada
et al. 2010). These changes may have negative impacts on the productivity
and suitability of the area for major crops in Brazil and the Cerrado (Assad
et al. 2008). Regardless of the predictions, researchers in land use plan-
ning and genetic breeding must consider adaptive or mitigation strategies.
Soil scientists must provide answers to questions such as how SOC storage,
water retention, GHG emissions, and other critical processes in Cerrado
soils will respond to higher atmospheric CO 2 and temperature, both in man-
aged and natural ecosystems.
(2) Assessment of natural resources . Sano et al. (2010) stated that, prior to their
mapping work, the only wide assessment of land use in the Cerrado had been
made in the 1970s (the large-scale Radambrasil project), clearly showing a
general deficiency in providing critical information for land use planning. In
fact, available estimates of geographic distribution and the estimated areas
for the Cerrado biome vary considerably. Thus, the need for precise, digital
mapping on land use and changes has often been stressed (Batlle-Bayer et
al. 2010). However, soil survey and mapping efforts are mostly based on
scales too small to be actually useful for local purposes. For instance, the
Brazilian soil map is on the 1:5,000,000 scale, and although more recent
efforts include the Minas Gerais State Soil Map on the 1:650,000 scale
(Ufv-Cetec-Ufla-Feam 2010), initiatives such as county-level surveys are
not generally envisaged in the near future. Innovative approaches such as
the construction of thematic maps of critical soil properties (e.g., pH, SOC,
and clay content) by geostatistical techniques such as kriging have been
made (Silva et al. 2010; Skorupa et al. 2012), but still at a small scale, and
only for few soil properties in two Brazilian states.
(3) Nature conservation . The Cerrado is the most biodiverse savanna biome
of the world, yet conversion of native ecosystems to agriculture is occur-
ring so rapidly that this biome is perhaps even more endangered than the