Submitted to: Northeast Potato Technology Forum Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 3/11/2008
Publication Date: 3/12/2008
Citation: Griffin, T.S., Honeycutt, C.W., He, Z., Larkin, R.P., Halloran, J.M., Olanya, O.M. 2008. Enhancing Potato System Sustainability: Storage and Cycling of Carbon and Plant Nutrients in Soil. Northeast Potato Technology Forum Abstracts. CD-ROM.
Technical Abstract: There are a number of factors that can limit potato productivity, including the degradation of soil resources. We established a long-term field experiment in Presque Isle, ME, in 2004, to establish the relative importance of the factors that impact yield and quality of the potato crop, including the retention, loss, and cycling of soil carbon (C) and nitrogen (N), and changes in plant available nutrients over time. There are five production systems included in this experiment, each designed to address a challenge to potato productivity: Standard Rotation: (2-yr barley-potato); Disease Suppressive (3-yr rotation, with mustard and sudangrass green manures followed by potato; Soil Conserving (3-yr rotation of barley, grass sod, and potato); Soil Improving (same as Soil Conserving, except with compost added to each crop); and Continuous Potato. Total C concentration in soil has increased as a result of annual compost application relative to all other systems, and has decreased slightly in the continuous potato systems. The latter is attributed to both the low residue return of potato and the intensity of soil disturbance in this system. Total organic N concentration in the soil has increased proportionately. More easily degradable C and N pools, like particulate organic matter C and N, are disproportionately enriched in the compost-amended system. Active C concentration, which is estimated using potassium permanganate oxidation of organic matter, is also increasing rapidly. No changes in labile C and N are noted among the other systems. Soil aggregate stability is increasing in both soil-based systems, even though soil C concentration and partitioning have not changed in the Soil-Conserving system, indicating the aggregate stability is not solely a function of soil C enrichment.