Cover Crop Mixtures May Reduce Nitrate Leaching and Fertilizer Application in Potato Production.

Nitrogen is considered as a limiting factor in potato production and contributes greatly to growth and development of tubers. However, high mobility of nitrate in the soil profile makes it susceptible to leach to the lower levels of soil which results in nitrate contamination of water tables. Selecting appropriate types of cover crops, as nitrogen scavengers, along with nitrogen management can reduce nitrate leaching and fertilizer application in potato fields.The effect of cover crop mixtures (oat/daikon, oat/peas, rye/daikon, rye/peas, peas/daikon and no cover crops) and four nitrogen fertilizer rates (0, 50, 100, and 150 kg ha^-1) was studied at the Research farm of University of Massachusetts in 2013-2014. Measurements were made for nutrient density of tubers, tuber yield, and nitrate leaching below the cover crop root zone. Our results showed that nitrogen application and nitrate leaching was lower in cover crop plots than no cover crop ones. Also, potatoes planted after cover crop mixtures had a higher tuber yield compared with those planted in no cover crop plots.