Document: JEN-3-33-7

The effects of nutrient heterogeneity on root allocation in Pisum sativum: A split root experiment.

DOHERTY, J.H.* and B.B.CASPER

University of Pennsylvania, Philadelphia, PA, U.S.A. ¹

Abstract:
Spatial nutrient heterogeneity in soils is ubiquitous in nature and often occurs on a scale smaller than that of a plant root system. Such patchiness has been shown to affect the proliferation of fine roots, other root architectural features, and total nutrient uptake by plants. These responses suggest that heterogeneity may also alter plant performance and/or population and community dynamics. To examine the effects of nutrient heterogeneity on the spatial distribution of roots, I performed a split root experiment with pea plants (Pisum sativum cv Little Marvel). Such experiments divide the root system of a single plant between two pots in which soils can be manipulated independently. In one pot, nutrients were spread homogeneously throughout the soil. In the other I put the equivalent amount of nutrients in a single core at the center of the pot. I measured whether the plant preferentially grew more roots in one pot than in the other. Based on known responses of roots to nutrient patches and the fact that plants can increase nutrient uptake in heterogeneous soils, I predicted that the plant would invest more roots in the pot with the single core of nutrients. However, nutrient distribution had no effect on root deployment between the two pots indicating no preference for either nutrient distribution.

Keywords: root, foraging, nutrient, heterogeneity, split-root

This abstract is being presented at: 3:30 PM in session:
ROOT PROCESSES