Effect of Stover Mulch on Soil Temperature, Corn Root Weight, and Phosphorus Fertilizer Uptake

Abstract

Bands of corn stover placed on soil in different positions relative to corn (Zea mays L.) rows decreased soil temperature at a 10‐cm depth 2.5C for maxima, doubled the proportion of root growth in the surface 5 cm of soil, and tripled fertilizer uptake from a surface‐applied band of ³²P‐labeled phosphorus fertilizer. The greatest increase in uptake occurred with the band of stover on both sides of the row. Total root growth to a depth of 15 cm was not greater with stover than without it.The increase in uptake was credited to the relatively greater root growth near the surface, which in turn was believed due to the temperature depression and a tendency for a more horizontal direction of root growth. While a more favorable soil moisture level, as found under mulch, would be necessary for root growth and proliferation, it was not considered initially responsible for directing roots closer to the soil surface.