| In the northern Yinshan Mountain of Inner Mongolia, the potato yield records have being increased constantly, it is often to harvest over 45000 kg/hm2, however, it is lacked of understanding on the population structure characteristics and the change rules with increasing of potato yield in its growth process. The northern of Yinshan Mountain area is one of the most important potato production base in our country, although the drip irrigation technology applied rapidly in recent years in this area, the potato yield was instability in most farmers, which has a larger gap with the highest yield records. Therefore, it is necessary to recognize the structure characteristics and changes of high yield potato under drip irrigation, which can give a guide for farmers to achieve the high production. In addition, phosphorus nutrition is one of important elements for potato production, however, compared with the nitrogen and potassium, phosphours nutrition characteristics in the potato, especially for high yield is less study in the pervious researches. The purpose of this study is to reveal the high yield potato population structure and its phosphorus nutrition characteristics through the comparison of yield components, dry matter production characteristics, photosynthetic performance, phosphorus uptake and utilization etc. of high yield farms and normal farmer. Based on the results, test the periodic regulation and management effect of phosphorus on the potato yield according to Phosphorus absorption characteristics, and summarizes the fertilizer management strategies according the phosphorus source supply, and finally provide the technical support for the optimal phosphorus management for high potato yield under the drip irrigation condition in northern Yinshan Mountain area of Inner Mongolia.The main results and conclusions are as follows:1. Compared with the farmer pattern, the number of tubers per plant high as 9.3%, commodity potato rate high as 2.3% in the high yield pattern, therefore, tuber number and tuber weight not only can synergistically enhanced, and these two yield component factors are most fundamental factors on improving of potato yield under the drip irrigation condition in the northern Yinshan Mountain area of Inner Mongolia.2. In order to harvest high-yield potato in the northern Yinshan Mountain area, the dry matter accumulation of potato population up to 14052.5～14831.7 kg/ha, daily accumulation quantity was 135.1～145.4 kg/ha,79.2～82.5% for harvest index. Photosynthesis indices including leaves area idex was 3.07～3.81 at the tuber bulking period and 1.50～1.88 at the starch accumulation period at least, total leaves area during was 169.4～172.7 104m2·d/ha.3. The total P uptake quantity can be up to 44.3～55.3 kg/ha in the high yield pattern condition, the phosphorus absorption ratio in each growing stage of potato population of northern Yinshan Mountain area in Inner Mongolia can be summarized as 8% at the seedling stage,26% at the tuber formation stage,42% at the tuber expansion period,24% at the starch accumulation period.4. The phosphorus release period of seed potato are mainly concentrated in the post emergence of seeding within 60d. The release quantity and rate were decreased with the time fly after sowing. The phosphorus contribution rate of seed potato was influenced by the phosphorus regulation level which is in the range of 65.8～80.3%, the highest yield was occurrences in 70.4% of the phosphorus contribution rate.5. The soil available P contribution rate is affected by the P supply levels, which ranged from 74.8% to 88.6%. The highest yield and high use efficiency of phosphorus fertilizer were occurrences in 74.8% of soil available P contribution rate, there is a significant logarithmic correlation between soil available phosphorus and the potato yield after 20 days of potato seeding, which can deduced the threshold of soil available phosphorus is 26.3 mg/kg.6. The phosphorus fertilizer application recommended by three major phosphorus sources over all planning method can effectively reduce the quantity of fertilizer application, the utilization rate of the fertilizer can be greatly improved under the same conditions, and the efficient phosphorus resource utilization can be maximized in the stage control condition for the phosphorus requirement according to the different growth stage, which can be recommended as the optimal management strategy for the potato production in the drip irrigation condition of northern Yinshan Mountain area in Inner Mongolia. The recommended formula of three major phosphorus sources for overall planning method as follows:Phosphorus application amount= (Objective yield* phosphorus requirement of 1000 kg tuber-soil available phosphorus* contribution rate of soil available phosphorus -Phosphorus storage in the seed potato* phosphorus contribution rate of seed potato)/ utilization rate of phosphate fertilizer... |
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