Potassium Fertilization for Long Term No-Till Crop Rotation in the Central-Southern Region of Paraná, Brazil

Abstract

Fertilization programs for annual crops in the state of Paraná, southern Brazil, are based on studies that focused on conventional tillage and were established more than 30 years ago. The primary purpose of this study was to assess potassium (K) fertilization on long-term (>30 years) no-tillage soybean, corn, wheat, and barley crops grown in rotation on Oxisols in the central-southern region of Paraná. A total of 47 experiments were carried out from 2008 to 2013, three of which addressed K calibration and the other 44, crop response to K fertilization. Critical K soil-test value and interpretation classes were established from the ratio between relative crop yield [RY = (yield without K/max yield) × 100] and soil K levels. Winter cereals were found to be more demanding of K than were soybean and corn; also, the former governed critical K soil-test value for crop rotation: 0.23 cmol c dm -3 in the 0.00-0.20 m soil layer. Recommended fertilization rates for soils in the low and medium soil K levels were established by using the build-up approach for soil correction; and those for the high and very high soil K levels were established by removing K at harvest and assessing economic return in crop response experiments. The K rates calculated for the high yield classes exceeded those currently recommended for use in Paraná.

Crop Yield Responses to Sulfur Fertilization in Brazilian No-Till Soils: a Systematic Review

“…Grain yields for different crops, regions, and crop harvests were compared by using the equation 1 to calculate a relative yield for each crop harvest in terms of the specific treatment leading to the highest yield as reference (Tiecher et al, 2018): -S contents, which spanned 48 crop harvests for the surface soil layer (0.00-0.20 m) and 34 for the subsurface layer (0.20-0.40 m), were used to construct a calibration curve for soil available S from the initial available SO 4 2--S content for the experiment and the relative crop yields of the plots receiving no S (controls) (CQFS-RS/SC, 2016; Vieira et al, 2016). The S rate recommended to obtain 95 % of the highest relative yield, which was considered to be the maximum economic efficiency (MEE), was determined by plotting the relative yield of each S Rev Bras Cienc Solo 2019;43:e0180078 rate and the respective rate used (Tiecher et al, 2018) (Lock et al, 2017).…”

Atributos Químicos Do Solo Em Área Cultivada Com Milho Sob Irrigação Com Água Salina

“…Resultados contrários ao presente trabalho foram reportados por Gonçalves et al (2011) estudando alterações químicas de um Neossolo Flúvico irrigado com águas salinas durante 65 dias e por Linhares et al (2013) em um Argissolo cultivado com berinjela irrigado com água de diferentes salinidades.O teor de potássio foi influenciado negativamente pela salinidade da água de irrigação (Figura 3) se ajustando ao modelo linear, com decréscimos na média de 4,17% para a CEa de 2 e 3 dS m -1 e 25% para a CEa 4 e 5 dS m -1 em relação a água de baixa concentração salina (1 dS m -1 ). A redução do y = -0,406x + 5,67 R² = 0estar relacionada ao fato de ser um dos nutrientes absorvido em maiores quantidades pela cultura milho(VIEIRA et al, 2016). Teores de potássio no solo (CEes) irrigado sob águas de diferentes salinidades ao 110 após o plantio.…”

Características químicas de um Argissolo e a produção de milho verde nos Tabuleiros Costeiros sergipanos

“…Entre os nutrientes, o K é um dos nutrientes absorvido em maiores quantidades pela cultura milho, apresentando relação direta e positiva com o número de grãos em espiga e com a massa individual de grãos (Vieira et al, 2016). Assim, vale ressaltar que, embora as parcelas com girassol tenham apresentado os maiores teores de Ca e Mg, o cultivo de girassol pode reduzir a produtividade do milho verde.…”