Submitted to: Northeast Potato Technology Forum
Publication Type: Proceedings
Publication Acceptance Date: March 2, 2009
Publication Date: March 6, 2009
Citation: Honeycutt, C.W., Griffin, T.S., Larkin, R.P., He, Z., Olanya, O.M., Halloran, J.M. 2009. Identifying constraints to potato system sustainability: soil and plant growth relationships. Northeast Potato Technology Forum. p. 1. Technical Abstract: Potato yield in Maine has remained relatively constant for over 50 years, despite increased production inputs. We evaluated Status Quo (SQ), Soil Conserving (SC), Soil Improving (SI), and Disease Suppressive (DS) potato systems to identify limitations to sustainability. Soil in the SI System had the lowest bulk density, highest microbial biomass C, and highest particulate organic matter C and N content. The SI and SC Systems exhibited the most stable soil aggregates. Highest Leaf Area Index (LAI) and Leaf Area Duration (LAD) were obtained in the SI System, and lowest LAI and LAD were observed in continuous potato under rainfed management. The same relationships were found under irrigated management; however, differences among cropping systems were much less distinct. These results indicate that management practices focused on improving the soil resulted in potato plant canopies with greater and longer lasting photosynthetic potential. This translated into higher yield, where the SI System under rainfed management increased total potato yield from 9-16 Mg/ha compared to continuous potato. Approximately the same yield increase was obtained through irrigation of the SQ, SC, and DS Systems. However, irrigation did not increase yield of the SI System. These results show that water was a primary constraint to increased productivity, and management practices that improve soils can be as effective as irrigation for reducing this constraint in the northeastern United States.