Abstract:

In order to provide theoretical basis to potato high yield and high quality cultural techniques, an experiment was conducted to investigate the effects of combined application of different nitrogen source and magnesium fertilizer on yield and quality of potato (Solanum tuberosum L.) tubers under field experimental conditions. The experiment design was the randomized complete block with three replications. Three nitrogen source (sole nitrate, sole ammonium, nitrate and ammonium mixed) and three rates of magnesium fertilizer (0, 75, 300 kg/hm2) were employed. The results showed that the different nitrogen forms had not significant influence on the yield of potato tubers, whereas the combined application of different nitrogen source and magnesium fertilizer had significant effects on the yield of potato tubers. Moreover, both sole nitrate (NO3-) supply, and mixed supply of nitrate and ammonium (NH4+) supply with Mg application can enhance the ratio of large and medium tubers of potato. The contents of total starch and crude protein in tubers of potato were not influenced by the combined application of different nitrogen source and magnesium fertilizer. Sole nitrate supply, or mixed supply of 50% nitrate and 50% ammonium, with 75 kg/hm2 magnesium application had a significant effect on the content of vitamin C in the fresh tubers of potato. The combined application of different nitrogen source and magnesium fertilizer had a significant impact on nitrogen, phosphorus and potassium and magnesium uptake by potatoes tubers. The different nitrogen source had not significant effect on the uptake of nitrogen, phosphate, potassium and magnesium of potato tubers. Except for potassium uptake, the uptake of nitrogen, phosphate and magnesium in potato tubers was increased with the rate of magnesium application increase. This study indicates that mixed supply of 50% nitrate and 50% ammonium with appropriate magnesium fertilizer can increase potato tubers yield and nutrient uptake, improve quality and raise commodity rate of potato.