Potassium nutrition in the first and second ratoon sugarcane grown in an Oxisol by a conservationist system
|Rilner Alves Flores1*, Renato de Mello Prado2, Marcio Alexandre Pancelli2, Hilario Junior Almeida2, Leandro Rosatto Moda2, Bernardo Melo Montes Nogueira Borges2, Jonas Pereira de Souza Junior2|
|The presence of mulch on the soil surface after the mechanical harvesting of sugarcane (Saccharum officinarum L.) enhances the cycling of nutrients, especially K, which can decrease K fertilizer recommendations for the crop. The aim of this study was to evaluate the effect of K addition to an Oxisol, with an initial concentration 0.07 cmolc K kg-1, in first and second ratoon (no-till) sugarcane cultures by a conservationist system, i.e. rational use of fertilizers, use of alternative inputs and especially the maintenance of residues in soil that was previously burned to facilitate cutting. The following K doses were tested: 0, 32.5, 65, 130, and 195 kg ha-1, arranged in a randomized block design with five replicates. Potassium content in the soil and in the plant, as well as the yield and the quality of stalks were evaluated. Soil K application increased K concentration in soil and plant, and was reflected in the production of stems, with higher production (87.5 and 107.5 t ha-1) with the use of 120 and 123 kg K2O ha-1 in first and second ratoon sugarcane, respectively. At the first 2 yr it was not possible to reduce the K fertilization in ratoon. Therefore, with the introduction of the conservationist system there was an increase (20 t ha-1) at the second ratoon regarding the first one with the same applied rate.|
|Keywords: Plant nutrition, residues covering, Saccharum officinarum.|
|1Universidade Federal de Goiás, Campus Samambaia, Escola de Agronomia, Rodovia Goiânia/Nova Veneza, km 0, Caixa Postal 131, CEP 74690-900, Goiânia, Goiás, Brasil. *Corresponding author (firstname.lastname@example.org).|
2Universidade Estadual Paulista UNESP, Faculdade de Ciências Agrárias e Veterinárias, Departamento de Solos e Adubos, Jaboticabal, São Paulo, Brasil.