Nitrogen Management for Maximum Potato Yield, Tuber Quality, and Environmental Conservation

There is a need to continue developing new management practices to reduce nitrogen (N) losses that affect air, soil, and water quality. The potato (Solanum tuberosum L.) crop is grown in many developing economics and plays a major role in daily food consumption. Traditionally, farmers over-apply N fertilizer in potato production. Three key components identified to increase N use efficiencies (NUE) are the use of crop varieties, a carefully controlled N application rate, and better synchronization between applied N and potato N uptake. The effects of N management on agronomic efficiencies for red (Sangre) and russet (Canela Russet) cultivars grown during 2003 and 2004 in the San Luis Valley of Colorado, U.S.A were studied. In this region the traditional farmer practices range on average from 180 to 240kg N fertilizer ha(-1). The results showed that optimum N application for maximum tuber yield and quality for Canela Russet was 157 kg N ha(-1) split as 90kg N ha(-1) applied at planting and three fertigations of 22kg N ha(-1) applied biweekly after initial tuberization. Maximum tuber yield and quality for the Sangre cultivar was observed with an N application rate of 90kg N ha(-1) applied at planting. The results indicate that tuber yield and quality can be affected by low N availability and N over-fertilization. It is important that site specific nitrogen management practices are developed that consider cultivar physiological responses to total nitrogen application as well as to the physiological stage when the nitrogen is applied to maximize yields, tuber quality, and economic returns while reducing N losses to the environment.