Phosphorus and root distribution and corn growth as related to long-term tillage systems and fertilizer placement

• Published in: Revista Brasileira de Ciência do Solo 2009-10, Vol.33 (5), p.1237-1247
• Main Authors: Costa, Sérgio Ely Valadão Gigante de Andrade(Universidade Federal do Rio Grande do Sul PPGCS), Souza, Edicarlos Damaceno de(Universidade Federal de Goiás PPGCS), Anghinoni, Ibanor(UFRGS PPG - Ciência do Solo), Flores, João Paulo Cassol(Universidade de Virginia Tech), Cao, Eduardo Giacomelli(UFRGS), Holzschuh, Marquel Jonas(UFRGS PPG Ciência do Solo)
• Format: Article
• Language: English
• Subjects: adubação fosfatada; eficiência de uso; P fertilization; preparo do solo; SOIL SCIENCE; soil tillage; utilization efficiency
• ISSN: 0100-0683; 1806-9657; 0100-0683
• DOI: 10.1590/S0100-06832009000500017

Soil and fertilizer management during cultivation can affect crop productivity and profitability. Long-term experiments are therefore necessary to determine the dynamics of nutrient and root distribution as related to soil profile, as well as the effects on nutrient uptake and crop growth. An 18-year experiment was conducted at the Federal University of Rio Grande do Sul State (UFRGS), in Eldorado do Sul, Brazil, on Rhodic Paleudult soil. Black oat and vetch were planted in the winter and corn in the summer. The soil management methods were conventional, involving no-tillage and strip tillage techniques and broadcast, row-and strip-applied fertilizer placement (triple superphosphate). Available P (Mehlich-1) and root distribution were determined in soil monoliths during the corn grain filling period. Corn shoot dry matter production and P accumulation during the 2006/2007 growing season were determined and the efficiency of P utilization calculated. Regardless of the degree of soil mobilization, P and roots were accumulated in the fertilized zone with time, mainly in the surface layer (0-10 cm). Root distribution followed P distribution for all tillage systems and fertilizer treatments. Under no-tillage, independent of the fertilizer placement, the corn plants developed more roots than in the other tillage systems. Although soil tillage systems and fertilizer treatments affected P and root distribution throughout the soil profile, as well as P absorption and corn growth, the efficiency of P utilization was not affected. O manejo do solo e de fertilizantes ao longo do tempo de cultivo pode contribuir para o rendimento e lucratividade das lavouras. Há, então, a necessidade de se ter e avaliar experimentos de longo prazo para que se consiga entender a dinâmica da distribuição de nutrientes e raízes no perfil do solo e seu efeito na absorção de nutrientes e no crescimento e desenvolvimento da cultura. Foi utilizado um experimento de 18 anos de duração em um Argissolo localizado na Estação Experimental da Universidade Federal do Rio Grande do Sul (UFRGS), no município de Eldorado do Sul, com a sucessão de milho no verão e aveia-preta consorciada com azevém no inverno, sob manejos de solos e modos de aplicação de fertilizantes. Os manejos de solo foram o convencional, plantio direto e cultivo em faixas, e a fertilização fosfatada (superfosfato triplo) foi a lanço, em linha e em faixas. A distribuição do P disponível (Mehlich-1) e das raízes de milho no perfil do