Management and Landscape Position Effects on Soil Physical Properties of a Coastal Plain Soil in Central Alabama, USA

Improved crop management is necessary due to raising production costs and environmental concerns. Input optimization from precision crop management might provide some solutions to these issues. Spatial variability of soil physical properties can significantly affect the implementation of precision agriculture techniques. A study was established in 2007 to determine the effect of management practices and landscape variability on soil physical properties (infiltration, aggregate stability and total C) of a 9 ha acre field located in the central Alabama Coastal Plain. The field was divided into three zones 6 summit, backslope and accumulation, using elevation, electrical conductivity and traditional soil survey data. Four management systems 6 conventional system with (CT+M) or without (CT) dairy manure, and conservation system with (NT+M) or without (NT) dairy manure – were established on a corn ( Zea mays L.)6cotton (Gossypium hirsutum L.) rotation in 2001. Infiltration, aggregate stability and C content were generally lower in CT. Manure significantly increased the C content (P ≤ 0.001), with 62% greater soil C content when manure was applied to CT, and 39% greater when applied to NT. Infiltration was greatest on the summit (14.5 cm/h), followed by backslope and accumulation zones (8.6 and 7.1 cm/h, respectively). No significant difference (P = 0.69 and 0.39, respectively) was found for aggregate stability and carbon between zones. Conservation tillage for 6 crop years thus far has improved infiltration and increased soil C content, whereas manure has only increased soil C content.