INCUBAÇÃO DE CALCÁRIO FINAMENTE MOÍDO E CARACTERÍSTICAS QUÍMICAS DO SOLO SOB CULTIVO DE SOJA E MILHO

The chemical changes in the soil and the behavior of soybean and corn resulting from the application of doses of finely ground calcitic and dolomitic limestone were studied. The experiment was carried out in 10 L pots in a 2x4 factorial scheme with four replications, whose treatments consisted of two limestones (calcitic and dolomitic) and four doses: 0.0; 3.0; 6.0; 9.0 Mg ha-1. The soil was incubated and sampled at 90, 200 and 300 days. At 90 days of incubation, the soybean was sown and harvested at the end of the cycle. Next, corn was sown, which was also harvested. The results showed that the increasing doses of lime influenced all soil and plant variables with a linear or quadratic effect; the levels of calcium, magnesium, their CEC saturations and the Ca/Mg ratio were affected due to the higher content of each nutrient in the respective corrective and the application of finely ground limestone increased base saturation to values ​​close to the value calculated at the lowest doses. , not reaching the desired value only at the dose of 12 Mg ha-1, reaching the reaction peak at 90 days, decreasing from this date.Estudou-se as modificações químicas no solo e o comportamento da soja e do milho decorrente da aplicação de doses de calcário calcítico e dolomítico finamente moído. O experimento ocorreu em vasos de 10 dm³ em esquema fatorial 2x4 com quatro repetições, cujos tratamentos consistiram em dois calcários (calcítico e dolomítico) e quatro doses: 0,0; 3,0; 6,0; 9,0 t ha-1. O solo foi incubado e amostrado aos 90, 200 e 300 dias. Aos 90 dias de incubação semeou-se a soja e colhida no final do ciclo. Em sequência semeou-se o milho, o qual também foi colhido. Os resultados mostraram que as doses crescentes de calcário influenciaram todas as variáveis do solo e das plantas com efeito linear ou quadrático; os teores de cálcio, magnésio, suas saturações na CTC e a relação Ca:Mg foram afetadas em função do maior teor de cada nutriente no respectivo corretivo e a aplicação de calcário finamente moído elevou saturação de bases para valores próximos do valor calculado nas menores doses, não chegando ao valor desejado apenas na dose de 9,0 t ha-1, atingindo o pico de reação aos 90 dias, decaindo a partir desta data Palavras-chave: incubação; calcário; reatividade; PRNT. Incubation of finely ground limestone and soil chemical characteristics under cultivation of soy and corn ABSTRACT: The chemical changes in the soil and the behavior of soybean and corn resulting from the application of doses of finely ground calcitic and dolomitic limestone were studied. The experiment was carried out in 10 dm³ pots in a 2x4 factorial scheme with four replications, whose treatments consisted of two limestones (calcitic and dolomitic) and four doses: 0.0; 3.0; 6.0; 9.0 t ha-1. The soil was incubated and sampled at 90, 200 and 300 days. At 90 days of incubation, the soybean was sown and harvested at the end of the cycle. Next, corn was sown, which was also harvested. The results showed that the increasing doses of lime influenced all soil and plant variables with a linear or quadratic effect; the levels of calcium, magnesium, their CEC saturations and the Ca:Mg ratio were affected due to the higher content of each nutrient in the respective corrective and the application of finely ground limestone increased base saturation to values ​​close to the value calculated at the lowest doses. , not reaching the desired value only at the dose of 9.0 t ha-1, reaching the reaction peak at 90 days, decreasing from this date. Keywords: incubation; limestone; reactivity; PRNT