Volf, Marcelo Raphael [UNESP]Guimaraes, Tiara Moraes [UNESP]Scudeletti, Daniele [UNESP]Cruz, Igor Vilela [UNESP]Rosolem, Ciro Antonio [UNESP]2019-10-042019-10-042018-01-01Revista Brasileira De Ciencia Do Solo. Vicosa: Soc Brasileira De Ciencia Do Solo, v. 42, 12 p., 2018.0100-0683http://hdl.handle.net/11449/185081Ruzigrass (Urochola ruziziensis) has a large capacity to take up K from the soil, including non-exchangeable forms, and can play an important role in nutrient cycling in integrated production systems. However, K transport to roots of brachiarias is not well known, nor the nutrient dynamics in the rhizosphere, where a concentration gradient may be established towards the non-rhizospheric soil, creating a favorable environment for the release of non-exchangeable K. This study aimed to evaluate the effect of ruzigrass on K dynamics in the rhizosphere and on non-exchangeable K release. Ruzigrass was grown in pots filled with a Latossolo Vermelho Amarelo (Typic Hapludox) that was collected at 0.00-0.20 and 0.20-0.60 m layer from a cultivated area and fertilized with 0, 30, and 60 mg kg(-1) of K, plus a treatment with forest soil, used as control. Thirty days after plant emergence, soil samples were taken at the following distances from the roots: 0.5, 1.0, 1.5, 3.0, 5.0, and 10.0 mm. For the highest exchangeable K rate (60 mg dm(-3)), the exchangeable K level was higher from 0 to 0.5 mm of the roots for both soils (0.00-0.20 and 0.20-0.60 m). Therefore, more K was transported to the rhizosphere than the plant could take up. A depletion of exchangeable K observed in the rhizosphere resulted in the release of K from non-exchangeable forms, as observed in the soils from 0.00-0.20 (60 mg dm(-3)) and 0.20-0.60 m (without application of K). Ruzigrass grown on low K soils without fertilizer application results in a larger exchangeable K depletion zone than in soils that were fertilized or originally high in exchangeable K, showing a high potential for K cycling in the system.12engUrochloa ruziziensisnon-exchangeable Kexchangeable Krhizospheric soilArtigo10.1590/18069657rbcs20170370S0100-06832018000100531WOS:000450845900001Acesso abertoS0100-06832018000100531.pdf57207758732595280000-0003-2001-0874