Effect of potato‖oat intercropping on nitrogen, phosphorus, potassium mass fraction and nutritional quality of potato

A potato‖oat intercropping field experiment was performed using four different potato∶oat row ratios (2∶2, 2∶4, 4∶2, and 4∶4) to determine nitrogen, phosphorus, and potassium content and the quality of the potatoes, using monocropped potato as the control. The results showed that as the growing process advanced, the nitrogen, phosphorus, and potassium content in potato stems, leaf decreased gradually from the flowering to harvest stages, while the nitrogen, phosphorus, and potassium content in tubers showed a rising trend. The nitrogen content in different organs of the potato consistently decreased in the following order: leafstemstubers from flowering to harvest. Furthermore, the accumulation and distribution centre of potassium and phosphorus were transferred to the tubers at harvest. Potato‖oat intercropping improved the nitrogen and potassium mass fraction but reduced that of phosphorus in the potatoes. The crude protein content of potatoes produced at a potato:oat intercropping row ratio of 4∶2 was the highest, and significantly higher than that obtained with monoculturing. Furthermore, an intercropping potato:oat row ratio of 4∶4 produced higher starch and lower sugar and vitamin C contents than the other ratios did. Therefore, these results demonstrate that rational intercropping patterns could improve the quality of potato tubers to some extent.