Abstract:

Understanding the potato water requirement, water surplus and deficit in the central and southern areas of Ningxia can provide support for rational arrangement of the supplementary irrigation schedule and improvement of the water use efficiency. Using FAO PM 56 method and field water balance equation, the changes of water requirement, consumption and water surplus and deficit of potato were analyzed by refining K_c coefficient. The results showed that the water requirement of potato during the whole growth period was 465.1-677.3 mm, which was significantly positive and negative correlation with temperature and precipitation, respectively. The water requirement was more in high temperature years, less in low temperature years, less in rainy years, and more in less rainy years. The water deficit at seedling and tuber expansion stage was positive, and most of it was negative from June to early August, and there were 7-12 ten days water deficit exceeding 10 mm/ten days. The period of water shortage was gradually extended from south to north, and the amount of water shortage was gradually increasing. The accumulated water deficit in the central arid zone from June to August was more than 300 mm. For this reason, measures can be applied such as drought-tolerant varieties, low-water consumption preceding crop, fallow rotation, plastic film mulching, ridge and furrow cultivation, water-saving supplementary irrigation during water deficit period to support the sustainable development of potato planting.

Key words: potato, water requirement, water surplus and deficiency, water use efficiency, central and southern Ningxia