Inor Ag. Assmann
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With the technological strides in the pro-
duction of grains, especially in the cerrado
regions, investments in fertilization have
turned into one of the main factors that lead
to high productivity in soils originally poor,
as far as fertilization goes. The idea that big
amounts of fertilizers are necessary for pre-
serving the productive potential has consol-
idated among the farmers. Nowadays, in ar-
eas of commercial crops, it is common to
witness the occurrence of tracts of land with
nutrient levels interpreted as high or very
high, by virtue of the residual effect of pre-
vious fertilizer applications.
Although soils with inbuilt fertility trans-
late into savings for the farmers, very often
unnecessary or over-dimensioned fertiliza-
tion applications are carried out, where the
fertilizers are quite inefficient. Agronomist
Álvaro Vilela de Resende, from Embrapa
Corn and Sorghum, explains that frequently
growers continue fertilizing their crops with
defined amounts of Nitrogen (N), Phospho-
rus (P) and Potassium (K), even in very fer-
tile areas, for fear of productivity declines.
“Considering that correctives and fertil-
izers represent 30% or more of the costs in
grain production systems at a time when
the national economy is facing hardships,
which ultimately adversely affect farmers’
income!”, he justifies. The PhD in Soils
and Plant Nutrition considers that more ef-
ficient fertilization is fundamental for the
competitiveness of the grains, like in the
soybean- corn binomial – crops that ac-
count for about 50% of the consumption
of fertilizers across the Country.
In the realm of agricultural research, Re-
sende explains that much work has been
done to check the response to fertilization in
direct plantingproduction systems and in soils
with inbuilt fertility, seeing that no conclusive
recommendations on the subject were avail-
able. Based on studies conducted in commer-
cial grain producing farms, a conclusion was
reached with regard to the viability, through
monitoring soil fertility with periodic analy-
ses, of associating the degree the nutrient re-
serves are plugged to fertilizer re-dimension-
ing practiced by the farmer”, he says.
The results demonstrated that it is possi-
ble to identify management conditions that
conciliate smaller costs with fertilization,
more efficient use of fertilizers and high-
er performance in the cultivation of grains
in soils with inbuilt fertility. Several stud-
ies were conducted, developed within the
realm of the Nutrient Supply Portfolio for
Brazilian Agriculture, involving several Em-
brapa and external partners’ research units.
The main project linked to the subject focus-
es on the efficiency of the use of fertilizers
and on the validation of new technologies.
Building profits
Fertilizationmanagement in soils with inbuilt fertility
has become an alternative for boosting farmers’ profits
