Dynamics of K in brachiaria ruziziensis rhizosphere and its absorption in the plant

• Grant number: 13/15439-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2013
• End date: August 31, 2014
• Field of knowledge: Agronomical Sciences - Agronomy - Soil Science
• Principal Investigator: Ciro Antonio Rosolem
• Grantee: Amanda de Barros Gomes
• Host Institution: Faculdade de Ciências Agronômicas (FCA). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

Potassium (K) of the soil can be classified into four classes: structural (mineral), non-exchangeable or hardly available, exchangeable and in solution. All soils present K in forms non-exchangeable that indirectly supply the plants need, because supplying those potentially. This study aims to evaluate, in a soil with 11 years of cultivation history and successive addition of potassium fertilizer levels, the release of non-exchangeable K in accordance with the provision promoted by the cultivation of Brachiaria. The experiment will be conducted in a greenhouse at the Department of Plant Production UNESP, Botucatu, in an Oxisol (Embrapa, 2006) medium texture (210 g kg-1 clay, 20 g kg-1 silt and 770 g kg-1 sand). For this experiment will be collected soil plots that received, in total, 0, 660, 1320 and 1980 kg ha-1 of K2O. The experiment will be conducted in a randomized block design with four treatments and four repetitions. Three plants of Brachiaria ruziziensis will be grown in order to obtain a mat of roots. In the aerial parts and roots will determine the dry matter and the K content. The soil will be separated in different distances from the root mat, and will analyze the exchangeable and non-exchangeable K.