| Ningxia southern mountain district rainfed agricultural regions, is a major potato-growing area. The potato is the major crops and cash crops in this region, in order to explore the effect of Fertilization on potato production, potato in different organs of the dry matter accumulation, NPK ceiling and accumulation characteristics in different rainfall conditions. The experiment using the way of field experiment and laboratory analysis method, respectively in Dazui Village Shutai Township Haiyuan County(rainfall about 300 mm), Dongzigou Village Xinying Township Xiji County(rainfall about 380 mm), Touying Town Yuanzhou District(rainfall about 415 mm),it were carried out field experiment. The mathematical model is established on the relationship between Xiji (N, K), Haiyuan NPK fertilizer dosage and the yield via the experimental study, field investigation and indoor analysis. It is tested on the Yuanzhou District of potato in different organs of dry matter, N, P and K contents and nutrient accumulation, quality of potato in different fertilization. The quality of different cultivars potato tuber in different planting region is analyzed by comprehensive analysis. The results showed that:1. When nitrogen and potassium fertilizers’dosages were 0-306 kg/ha and 0-92 kg/ha, the yield of potatoes increased with dosage increasing in XiJi county; When their dosages exceeded 306 and 92 kg/ha, the yield of potatoes decreased with dosage increasing; We made the mathematical model and the economical analysis about the effects of the nitrogen and potassium fertilizers’ dosages on the yield of potatoes in XiJi county, and suggested that when the target yield was 30000 kg/hm2 the fertilization dosage ranges should be reasonable,286-306 kg/ha for Nitrogen,63-92 kg/ha for potassium,30 t/ha for organic fertilizer;2. The results showed that the optimum nitrogen, phosphorus, and potassium application amount acquired the highest yield was 267.3 kg/ha,138.9 kg/ha, and 82.1 kg/ha, respectively; that acquired the highest economic value was 258.6 kg/ha,131.71 kg/ha, and 71.1kg/ha, respectively; that acquired the highest starch content was 183.9 kg/ha,106.4 kg/ha, and 87.6 kg/ha, respectively;3. Dry matter accumulation of potato from seedling stage to the mature harvest showed "S" type growth curve, by curve fitting of potato dry matter accumulation accorded with the logistic growth function y=a/(l+be-cx), the dry matter accumulation faster in squaring stage to the tuber expanding stage, at the seedling and harvest period of slow growth, rapid accumulation of dry matter in different processing schedule reveal differences, the main factors of affecting dry matter accumulation is nitrogen. From different growth period, dry matter accumulation is relatively small in the seedling stage (from emergence to bud stage, about after the emergence of 25d), accounting for about 3.8% of dry matter accumulation during the growth period. Dry matter accumulation accounted for 33.7% in bud stage to flowering stage (tuber formation period, about 27d). The accumulation of dry matter was the largest in the tuber expansion period to the starch accumulation period (about 22d), which accounted for 40.99% of the total accumulated in the whole growth period. Dry matter accumulation of mature period accounted for about 21.38%.4. The nitrogen, phosphorus and potassium content of different organs is different in different growth period, nitrogen content of underground part, stems, leaves falling during whole growth period, the content sequence in different organs from seedling stage to tuber expansion period nitrogen is leaves> stems> underground part> tuber and it is leaves> tuber> stems> underground part from tuber expansion period to maturation period. Phosphorus and potassium element with the growth process is an overall downward trend, different growth period fluctuation, tuber bud after a period of phosphorus content tends to be stable. The content sequence of phosphorus is leaves> tuber> stem> underground part in seedling stage, and it is leaves> stem> underground part> tuber in maturation period. The potassium content showed a larger difference in growth period, the potassium content of stems and leaves increased in seedling stage, then potassium content falling with the growth process, The potassium content sequence is stems> leaves> tuber> underground part before the accumulation of starch and it is stems> tuber> leaves> underground part from starch accumulation to maturation period.5. Potato NPK uptake accumulation rule is "S" shape curve and accumulation by different fertilization treatment differences, in line with the function y=a/(l+be-cx) model, nitrogen, phosphorus and potassium accumulation measured values showed a high degree of positive correlation ((r> 0.9500) with the logistic equation between simulated values. The potato lack of nitrogen fertilizer, nitrogen, phosphorus and potassium rapid accumulation period than the nitrogen fertilizer treatment were earlier, lead to premature aging potato, the nitrogen treatment is relatively late.6. The reasonable amount of fertilizer and the ratio can effectively improve the nutritional quality of the potato, the unbalance or excessive amount of fertilizer application, the nutritional quality is low.7. From vitamin C, starch, crude protein, big potato rate, the analysis results show that average membership function values>0.4 quality to be good, mainly distributed in 5 counties of Guyuan and Haiyuan County, accounting for 62.16% of the total amount of sampling, potato quality in Yanchi County and Tongxin county is relatively poor, reducing sugar, nitrate indicators flat membership function values are>0.4, accounting for 24.3% of the total amount of sampling. Considering the advantages and disadvantages of the two aspects of the quality indicators, Longshu 3, Zhuangshu 3, Qingshu 9, summer wave, Atlantic comprehensive quality index is relatively good, from the point of counties distribution, Haiyuan County, Pengyang County and Yuanzhou District, potato quality is the best. |
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