Parcelamento de doses de potássio no rendimento da cultura da soja

Abstract

The agricultural aptitude of soils is highly dependent on the capacity of supplying nutrients even if fertility is high, built, or recovered through management of soil fertility. The practice of growing intensively soybeans and corn for many years without rotation alters the balance and the relative availability of K into soil, if no replacement is made. The objective of this research is to evaluate the development of soybeans with the fertilization of potassium chloride, applied in furrow at seeding and after topdressing. We conducted field research in the city of Presidente Castelo Branco-PR on classified soil as Red type with sandy texture. It was used soybean cultivation BMX POWER RR medium cycle. The five experimental treatments of 22.5 m2 each, was made with seven replications, each one with randomized block design. The treatments used were doses of 00, 30, 60, 90 and 120 fractionated K2O kg ha-1, applied at sowing and topdressing. It was evaluated % emergency, (30 days after germination), number of pods / plant, height of the plant, height of the seed insertion (on maturity) and weight of 1000 seeds. The data were submitted to ANOVA and values compared by testing polynomial regression (p <0,05). Statistical analysis used the comparison test by Tukey average, 5%. The application of K did not provide gains to culture. On the height analisys of the plant, insertion on the first seed, wheight of the seeds, we observed that we had no significative results related to the K dosis used. The results demonstrate the influence of antagonistic interaction between increasing doses of potassium in relation to levels of absorption of magnesium and boron in soybean cultivation.