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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Soybean and Soil Potassium Pools Responses to Long-Term Potassium Fertilization and Deprivation under No-Till

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Author(s):
Firmano, Ruan Francisco [1] ; Melo, Vander de Freitas [2] ; de Oliveira Junior, Adilson [3] ; de Castro, Cesar [3] ; Ferracciu Alleoni, Luis Reynaldo [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo ESALQ USP, Luiz de Queiroz Coll Agr, Soil Sci Dept, Av Padua Dias 11, BR-13418000 Piracicaba, SP - Brazil
[2] Fed Univ Parana UFPR, Dept Soils & Agr Engn, R Funcionarios 1540, BR-80035050 Curitiba, Parana - Brazil
[3] Brazilian Agr Res Corp Embrapa, Soybean Natl Ctr, Rod Carlos Joao Strass, BR-86001970 Londrina, Parana - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Soil Science Society of America Journal; v. 83, n. 6, p. 1819-1829, NOV-DEC 2019.
Web of Science Citations: 0
Abstract

Lack of potassium (K) fertilization can affect the nutrient reserve in soil and soybean {[}Glycine max (L.) Merrill] yield in humid tropical agroecosystems. The effects of K management in soil K pools and soybean nutrition is best evaluated by taking samples from long-term experiments. The aim of this study was to investigate changes in K pools and soybean nutrition as a result of K fertilizer deprivation in an Oxisol under no-till. Soil samples were collected in a field experiment started in 1983 in southern Brazil. Non-exchangeable K contents were extracted by boiling HNO3, whereas exchangeable K contents were extracted by Mehlich-1 and ion exchange resin. Grain yields and K contents in grains and index leaves (trifoliolate leaflets) were also obtained. Potassium fertilizer deprivation restricted soybean yield and reduced exchangeable K in a nonlinear fitting. The total K contents were influenced by K rates, without effects by K application. The 1 M HNO3 solution had high positive correlations with exchangeable K extractants, K leaf, and K grain contents. However, the exchangeable K extractants were better for interpreting the results due to higher correlations with yield and superior sensitivity to K application after deprivation. Potassium applications influenced K removals by soybeans and K leaf contents. The results indicate that long-term K management has effects on stable K pools (non-exchangeable and total K) and highlights that the buffer capacity of exchangeable K was strongly related to these stable pools. This underscores the importance of avoiding a negative K balance in soybean production systems to conserve K reserves and exchangeable forms. (AU)

FAPESP's process: 15/18952-3 - Residual effect of potassium fertilization on the forms of the nutrient in the soil
Grantee:Ruan Francisco Firmano
Support Opportunities: Scholarships in Brazil - Master