ARS | Publication request: Effects of Potato Cropping Systems and Irrigation on Soil Organic Matter Composition

Submitted to: Northeast Potato Technology Forum
Publication Type: Abstract Only
Publication Acceptance Date: February 19, 2010
Publication Date: March 10, 2010
Citation: He, Z., Honeycutt, C.W., Zhang, H., Larkin, R.P., Olanya, O.M. 2010. Effects of Potato Cropping Systems and Irrigation on Soil Organic Matter Composition. Northeast Potato Technology Forum. P13.

Technical Abstract: Soil organic matter (SOM) plays an important role in soil fertility, thus in sustaining potato production. To investigate the impact of crop rotation on SOM composition, we sequentially extracted organic matter by water (WEOM) and sodium pyrophosphate solution (PEOM) from 10 potato field soils which had three-year crop rotations with or without irrigation. We quantified their elemental compositions. Different contents of P, Ca, Al, and Fe were observed among the PEOM fractions from fields with different rotation patterns. However, the elemental contents in PEOM from irrigated fields were consistently lower than those from the corresponding rainfed rotation fields. The structural features of these WEOM and PEOM samples were further characterized by Fourier transform infrared (FT –IR) spectroscopy. Generally, the impacts of rotation and irrigation practices were reflected by changes in FT-IR band intensity in the 3020-2800 cm-1 (C-H of methyl and methylene groups), 1740-1700 and 1640-1600 cm-1 (C=O from amide, carboxylic or ketone)regions. This research improves our understanding of how crop rotation and irrigation impact soil organic matter composition.