Root Development and Rooting Patterns of Soybean (Glycine max (L.) Merrill) Evaluated Under Field Conditions¹

Abstract

The soybean (Glycine max L.) root system, by 21 days after planting, consisted primarily of secondary lateral roots that had developed from an enlarged upper 10‐ to 15‐cm segment of the “taproot.” Four longitudinal rows of lateral roots spaced at 90 degree intervals around the taproot developed acropetally. These laterals grew horizontally for 40 to 50 days and, after reaching 35 to 40 cm in length, turned downward, providing extensive deep penetration of the soil profile. Root growth and development occurred in three phases, each phase corresponding to specific vegetative or reproductive stages. The completion of each phase of development represented further penetration of the soil profile and proliferation by the root system. Root dry weight was concentrated in the upper portion of the soil profile, 90% or more in the upper 7.5 cm early in the season and in the upper 15 cm during the remainder of the season. Differences were observed among the eight varieties sampled for rate of root developmnt, total root dryweight accumulated, and type of rooting pattern.

Latent heat in soil heat flux measurements

“…At this size, soybean root growth in the plant inter-row is considered minimal (cf. Mitchell and Russell, 1971). Because plants were small, the field site can be considered to be effectively bare.…”

Adubação com molibdênio em soja, na presença ou ausência de calcário aplicado na superfície do solo, em plantio direto

“…Parte dessa ocorrência pode ser atribuída à menor quantidade de raízes de soja nos primeiros 2,5 centímetros de solo (MITCHELL & RUSSELL, 1971). Nessa zona é que se verificou correção dos fatores de acidez do solo nos tratamentos com calcário (Tabela 1); abaixo de 2,5cm, os resultados da análise dos fatores de acidez do solo calcariado à superfície eqüivalem aos do solo não calcariado, na profundidade de 0-2,5cm.…”

Nitrogen rhizodeposition from soybean (Glycine max) and its impact on nutrient budgets in two contrasting environments of the Guinean savannah zone of Nigeria

“…They were placed on the top of the rows or ridges, 0.30 m deep into the soil. Ninety percentages of soybean roots are typically found in the top 0.15 m of soils (Mitchell and Russell 1971). Two soybean plants were grown in each cylinder.…”