Improving nutrient-use efficiency in chinese potato production: Experiences from the United States

Potato (Solanum tuberosum L.) is the fourth most important food crop in the world after corn, wheat, and rice. It is adapted to a wide range of growing conditions, producing high yields with a nearoptimum balance of nutrients for human consumption. China is the world's largest potato producer and continues to account for a large part of the global increase in potato production. Although the potato can be highly productive, it has a relatively shallow root system and often requires significant nutrient inputs to maintain tuber productivity and quality. Each metric ton of tubers removes approximately 3.8 kg nitrogen (N), 0.6 kg phosphorus (P), and 4.4 kg potassium (K). Proper nutrient management, therefore, is extremely important for sustaining high tuber yield and quality. Lack of adequate balanced fertilization in China is reportedly a yield-limiting factor in some areas. For example, potassium (K) is very important for producing a potato crop with high tuber yield and quality. Limited K resources in China and continued cropping have resulted in below-adequate levels of soil K in many regions of the country, which will impact potato production. On the other hand, based on U.S. experience, the high nutrient demand by potato, application of high rates of fertilizer, and production on coarser textured soils can result in nutrient losses. Nutrient best-management practices are developed with the objective of optimizing production, net returns, and minimizing environmental degradation. In general, optimal N management has had the most important impact on tuber yield and quality compared with the other essential elements. Best management practices for N fertilization include appropriate selection of rate, source, timing, and method of application. Optimal management of irrigation is also important to improve N-uptake efficiency and minimize N losses while maintaining high yields and quality. Phosphorus is another key nutrient important from both production and environmental standpoints. Adequate P is required for optimum tuber-set, while excessive rates may result in soil-P buildup and potential runoff problems. This review will focus on various management techniques to maximize nutrient-uptake efficiency by potatoes.