Influence of nitrogen supply on cadmium accumulation in potato tubers

• Published in: Journal of plant nutrition 2011-01, Vol.34 (3), p.345-360
• Main Authors: Jonsson, E. Helene Larsson, Asp, Hakan
• Format: Article
• Language: English
• Subjects: Agricultural Science; Agronomy. Soil science and plant productions; ammonium; ammonium sulfate; Biological and medical sciences; Cadmium; calcium; calcium nitrate; Chemical elements; correlation; cultivars; diet; Economic plant physiology; Fertilizers; field experimentation; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; genetic variation; Jordbruksvetenskap; leaves; Metabolism; Metabolism. Physicochemical requirements; nitrate; nitrogen; Nitrogen fertilization; nitrogen fertilizers; Nitrogen, phosphorus, potassium fertilizations; NPK fertilizers; Nutrition. Photosynthesis. Respiration. Metabolism; phosphorus; Plant physiology and development; planting; potassium; potato; Potatoes; Soil and water pollution; soil pH; Soil science; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Solanum tuberosum; split application; tubers
• ISSN: 0190-4167; 1532-4087; 1532-4087
• DOI: 10.1080/01904167.2011.536877

The effect of different levels and forms of nitrogen (N) fertilizer on cadmium (Cd) concentrations in potato (Solanum tuberosum L.) tubers, a large component of the northern European diet, was investigated with the aim of decreasing the Cd content. A high and a low Cd-accumulating cultivar were used in two field trials and a pot experiment. The N fertilizers tested were balanced N- phosphorus (P)- potassium (K) 11-5-18 + micronutrients, alkaline calcium nitrate and acidic ammonium sulfate at levels of 60, 160, and 240 kg N ha-1 at planting or (for the higher N doses) split between two or three occasions. The Cd concentration in tubers of both cultivars decreased when increasing the N fertilizer from 60 to 160 or 240 kg N ha-1, indicating that Cd uptake and translocation are not positively correlated to the growth rate of the potato plant. A strong positive linear correlation was found between the Cd concentration in leaves at 77 days after planting and the Cd concentration in tubers at harvest, irrespective of N treatment, although the Cd concentration was three-fold higher in the leaves. The genetic variation in leaf and tuber Cd accumulation was consistent, regardless of the form of N fertilizer used. Ammonium sulfate decreased soil pH and increased tuber Cd concentration in both cultivars compared with NPK fertilizer, possibly due to increased amounts of plant-available Cd arising from the pH decrease after ammonium sulfate application. The tuber Cd concentration in the low Cd-accumulating cultivar increased when fertilized with calcium nitrate, an effect attributed to Cd availability being influenced by the increased Ca2+ concentration.