Intercropping and Low-Rate Banded Fertilizer to Address In-Season Nitrogen Leaching Risk in Potato Grown on Sandy Soils

Abstract

Groundwater nitrogen contamination is a concern where potato (Solanum tuberosum) is produced on coarse-textured, low organic matter soils with poor water and nutrient holding capacity. Potato was intercropped with yellow mustard (Sinapis alba) and winter rye (Secale cereale), and low-rate supplemental banded (53 kg N ha^− 1; 175 kg N ha^− 1 total seasonal rate) fertilizer applications were compared to standard rate broadcast (158 kg N ha^− 1; 280 kg N ha^− 1 total seasonal rate) fertilizer applications. Potato yield and intercrop growth and nitrogen uptake were quantified. Intercrops grew poorly in a wet year and were outcompeted by potato, but performed well in a year with average precipitation and accumulated up to 25.7 kg N ha^− 1 in yellow mustard and 8.0 kg N ha^− 1 in winter rye. Neither intercropping nor fertilizer treatment negatively impacted potato total marketable yield in either study year. Though intercrop establishment and success appear to vary with climatic conditions, integrating intercrops and low-rate banded fertilizer applications could be a low-risk technique to presumably reduce in-season nitrogen leaching risk while maintaining potato yields.