Potato Cropping Systems and Their Impact On Profitability.

Sustainable crop systems and management practices are needed to improve agricultural viability and rural economic vitality in Maine and the surrounding region. Our on-going research objectives are to (1) identify the constraints to potato system sustainability, and (2) develop practices and management strategies to overcome or reduce those constraints. Limitations to sustainability are being identified through an interdisciplinary evaluation of cropping systems managed as: (a) Status Quo (SQ) representing a typical 2-yr rotation of barley underseeded with red clover followed by potato; (b) Soil Conserving (SC), a 3-yr rotation with limited tillage and additional year of forage (barley/timothy-timothy-potato); (c) Soil Improving (SI), a 3-yr rotation with compost amendments added each year (barley/timothy-timothy-potato); and (4) Disease Suppressive (DS), a 3-yr rotation featuring crops with known biofumigation or disease-suppressive capability (Mustard/rapeseed-Sudangrass/rye-potato). These systems were conducted under both irrigated and non-irrigated conditions, and were also compared to a continuous potato (PP) control. Each system was evaluated for its impacts on soil physicochemical and biological properties; plant growth; nutrient availability; plant diseases; profitability and risk; and their interactions. Concurrent research has also been conducted to improve economic viability with details concerning the potential sustainability of each system and alternative management cost options transferred to producers. This presentation summarizes the economic implications of each system with respect to producer profitability. Some systems (e.g., rotation with Sudangrass) were not designed to be profitable, but serve to identify key system constraints. Our results show that there is a wide range of potential profitability from one system to another. With respect to economic potential we found that the crops included in a three year cycle were important, and that cultural practices such as adding compost or irrigation affected potential profitability. There were significant differences in yields with the largest effects observed in the DS and SI systems.