Effect Of Potassium Fertilizer And Water Supplement For Dry Land Potato

The potato was tested in the field experiment. The split plot was designed in the field experiment. The main treatment was potassium supplying, the subsidiary treatment was water supplement period. The purpose of the experiment was to study effect of water supplement period and potassium supplying on growth, yield, water use efficiency (WUE) and potassium using efficiency of potato. The water and fertilizer coupling threshold of harmonizing yield and quality was put forward in this article. The result showed that:1. The soil water and soil fertility were improved dramatically when applying potassium fertilizer and water supplement in seedling stage, it can improve plant growth, increase the photosythetic rate and the yield. seedling stage was considered as the optimal water supplement period to potato in arid and semi-arid in north china (Supplementary water amount is 90m3/hm2). The highest yield and economic yield reached 36324.97kg/hm2, 35178.71kg/hm2 respectively when the potassium application rate at 150kg/hm2, 127.48 kg/hm2 respectively.2. The plant height and root-shoot ratio were all enhanced though water supplement and applying potassium fertilizer, increased 6.85-24.68%, 14.63%~94.79% comparing with CK, respectively. Under the potassium application rate at 150kg/hm2 commodity potato rate, tuber weight per plant, starch contain were all increased especially water supplement when seedling stage, the highest commodity potato rate, tuber weight per plant, starch contain reached 76.94%, 1.33kg, 19.79% respectively.3. Under the condition of water supplement when seedling stage and the potassium application rate at 150kg/hm2, Water use efficiency (WUE) at population and yield level of potato were the highest, they were 41.71kg/mm·hm2, 94.21kg/mm·hm2 respectively, the yield also were highest. The WUE at leaf level was the lowest, but its yield was the highest. The result of WUE at yield and population level matched practical case, but the WUE at level failed to reflect the change and relationship between the yield and WUE, it was not compatible to practical case.4. Under the condition of less soil water and rainfall in seedling stage, water supplement can improve soil moisture, increase potassium biological availability, which would benefit the absorption of potassium and improve the efficiency of potassium. The highest efficiency of potassium was 37.92kg/kg, but the efficiency of potassium increased with the increase of potassium rate when the potassium was less than 150kg/hm2, they were decreased by higher potassium application.5. The optimal treatment of water and fertilizer coupling was K2W1 (the potassium application rate at 150kg/hm2, water supplement when seedling stage).