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Potassium management over 60 crops: A long‐term study on an Oxisol under no‐till
Author(s) -
Firmano Ruan F.,
Oliveira Junior Adilson,
Castro César,
Alleoni Luís R. F.
Publication year - 2020
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.1002/agj2.20456
Subject(s) - oxisol , agronomy , fertilizer , potassium , human fertilization , nutrient , cropping system , environmental science , chemistry , soil water , crop , soil science , biology , organic chemistry
Potassium (K) is a typical yield‐limiting nutrient for soybeans [ Glycine max (L.) Merr.] in humid tropical regions. The effect of fertilization on K balance over 32 yr of continuous cropping was investigated in a highly weathered Rhodic Hapludox under no‐till. The nutrient balance was calculated based on the amounts of K added via fertilization and on the amounts removed by the crops. Potassium rates interfered with yields over time and modified the final balance of K in the system. Depending on K rates, the balance tended to be positive or negative, and the range of K rates evaluated allowed us to establish conditions of either continuous K depletion, resulting from K removals by harvests, or the accumulation in soil under high rates. In this range, indicators of the efficiency of K fertilizer also varied and made it clear that K fertilizer is not the only source of K for plants.