Potassium Nutritional Properties Of Potato Crop In The Yinshan Area Of Inner Mongolia And Its Diagnosis

Potato usually consumes larger amounts of potassium. Better understanding on the characters of potato potassium nutrition is the basis of potato potassium nutrient management. In resent years, with the development of potato industry and the increasing of potato production benefit, the application amount of potassium fertilizer increases greatly and the ratio of potassium in the compound fertilizer formula designed for potato increases as well, which often result in overuse of K fertilizer and cause wasting of potassium resources in some districts. Therefore a proper potato potassium nutrient management technique is necessary. In such case, the objective of this study are:1. to understand potato potassium nutritional properties in Yinshan area of Inner Mongolia, which is one of main production areas of potato in China; 2. to establish the potassium diagnostic index with the fourth leaf petioles from the apex; 3. to propose potato K management suggestions. All of the works aim to establish the foundation or provide technical information for potassium nutrition management of potato. The obtained results were as follows:1. The potato tissue K concentration declined with growth process under all K supply levels. The rate of potassium absorption by potato plants and its accumulation in plants increased with-increasing of potasium application rates. Before the tuber bulking period of potato, potato shoot was the main organ for K accumulation, but potato tuber became the main organ of K accumulation at the tuber bulking period.2. With the increase of the application amount of potash fertilizer, potato plant biomass and yield increased. When the potassium fertilizer application rates increased to a certain extent, plant biomass and yield no longer increased with K application rates, however the potassium uptake by potato plants still continued to increase within the range of K used. Therefore, luxury absorption of K by potato plants occurred with high K availability in the media.3. The potassium content of the fourth leaf petioles from the apex of potato plant was highly sensitive to the available potassium in the media and it had close relationship with the potassium concentration in shoot, therefore it dan reflect the status of potassium nutrition of potato. The critical value of potassium content of the fourth leaf petioles from the apex of potato plant was 4.45%.4. Nitrogen and Phosphorus concentration in different organ of potato decreased with plant growth process. The absorption rate of N and accumulation of N increased in potato, but the P absorption rate and the accumulation of P in potato deceased with the increasing of K application rates.5. In Yinshan area of Inner Mongolia, when potassium application amount to the potatoes was less than 241.5kg/hm2, the potassium balance coefficient was less than 1, implying the soil potassium would decreased significantly. When potassium application rate to the potatoes was more than 362.25 kg/hm2, the potassium balance coefficient was greater than 1, which would cause the accumulation of K in the soil.