Doses and potassium partitioning methods in soybean production components in an Amazonian savanna

Sandra Catia Pereira Uchoa, Ronaldo Jaques Pain, Jose Maria Arcanjo Alves, Deyse Cristina Oliveira Silva, Valdinar Ferreira Melo, Samuel Silva

Resumo


After nitrogen, potassium is the macronutrient most required by soybean. To meet soy bean growth
demands, it is necessary to use high K doses, which can lead to losses via leaching. The objective of the
current study was to evaluate the effect of doses and methods of K fertilization on the components of soybean
production, in the Yellow Latosol of an Amazonian savanna. The experiment was conducted using randomized
complete block design with four replicates. Plots consisted of two fertilization methods (M1 – fertilization on
planting and at 35 days after emergence - DAE and M2 – on planting, then divided between 20 and 35 DAE).
Subplots where five doses of potassium (K2O at 0, 40, 80, 120 and 160 kg ha-1) were randomized. Measured
variables were: plant stand (PS), plant height (PH), height of first pod insertion (FP), number of pods per
plant (PP), bean mass per plant (BM), and bean yield (BY). Because of the low exchangeable K content and
medium texture of the study soil, deployed methodology consisting of plant fertilization and two applications
to facilitate high soybean yields. Agronomic efficiency proved to be a good indicator for assaying the best K2O
dose, as it is sensitive to initial soil exchangeable K levels. The dose giving maximum agronomic efficiency
was 88.5 kg ha-1 of K2O, converting each kg of K2O in 14.3 kg of soybeans.

Palavras-chave


Adubação. Cobertura. Eficiência Agronômica. Glycine Max (L.) Merrill.

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DOI: http://dx.doi.org/10.18227/1982-8470ragro.v12i4.5332

Direitos autorais 2018 REVISTA AGRO@MBIENTE ON-LINE

Revista Agroambiente On-line ISSN 1982-8470 (online), www.agroambiente.ufrr.br. E-mail: agroambiente@ufrr.br. Licença Creative Commons
Este obra está licenciado com uma Licença Creative Commons Atribuição-SemDerivações-SemDerivados 3.0 Brasil.