| Fujian province, which is one of the earliest regions of the planting potato, belongs to the winter-planting potato zone with more than 300 years of potato-planting history in the South China. The planting areas of potato have been increased along with structural adjustment for agriculture industry in Fujian. The potato has been already increasingly important among spring crops. In recent years, there has been a fundamental change in the function of potato, which was from traditional grain-vegetable to fallow foods, industrial starch and biomedicine. The demand for potato grows with each passing day. Therefore, striving to develop the winter-planting potato is great significance for Fujian province.Production of potato in Fujian began with later 1980s. The author was in responsible for the extend of winter-planting potato and found out that there were many problems, such as confusion variety, cultivation management extensive, difference of cultivation styles, definition of standard, imperfect cultivation modes et al., which leaded to the imbalance of development in different regions and the obvious difference between yield and commodity. Based on successful experience of winter-planting potato with high yield in the south of Fujian province and combined with actual production in Fujian, the key cultivation methods of sandwich straw, replenishing soil and covering seed by organic fertilizer had been integrated by used the cultivation of sandwich straw. And the high yield cultivation method of sandwich straw potato had been put forward in 2003 and was widely applied in the producing areas, Longhai. Then this technology first elected by Fujian Provincial Department of Agriculture and Fujian Development and Reform Commission has been demonstrated and extended over the province and spread to Huizhou in Guangdong province. For improving the sandwich straw model, the high yielding and high efficiency technology system and practical technical standard of cultivation had been established and formulated in order to provide technological support for the further development of potato. Therefore, in this paper Zihua 851 and Zhongshu 3 were employed as the plant materials for the experiments on agronomic characteristics, formation of high yield, soil microbes and physiological mechanisms of sandwich straw potato from 2007 to 2010.1) Different cultivation methods had been researched. The results showed that the method of sandwich straw model was the best for its comprehensive performance. This method is easy for operation for farmers to accept with pleasure. It could conserve soil water and increase temperature, create loosen soil structure, effectively reduce cracked and green tuber percentage, increase marketable tuber percentage, and more importantly significantly increase potato yield. In the process of demonstrating, its characteristics of high-yield and practicability had also been tested. So this technique should be recommended in such place as Fujian.2) The results of sandwich straw potato growth and development indicated that the weights of leaf, stem, roots and long creeping stems by sandwich straw model were higher than the control, but it was different of long creeping stems growth among different varieties. The results of anatomic and histological structure showed that the technique of sandwich straw model could promote tuber growing widely and its intumescence. The organ differentiation of tuber was coincident, which was beneficial to the accumulation of nutritive. The appearance of amyloplastid could increase the quality of potato tuber.3) The key cultivation techniques, such as sandwich straw consumption, nitrogen (N) and potassium (K) application amount, and planting density, had been determination. The results showed that there was not significant difference between 2700 kg/hm2 consumption of rice straw and 4200 kg /hm2. But the consumption of 2700 kg/hm2, which could save cost and increase economic benefits, was better than 4200kg/hm2. The potato yield correlated to the amount of N and K application parabolically. Under the test conditions, the economic N and K application were respectively determined to be 240 kg/hm-2 and 201 kg/hm-2 with an expected yield of 3.75 t/hm-2. On the average, 6.4 kg for N and 5.4 kg of K fertilizers were required to produce 1 000 kg tubers. And the nitrogen-potassium rate was 1︰0.84. The linear model analysis results of nine kinds of planting density indicated that yield increased as planting density increased. The yield was the highest with planting density of 82, 500 plants per hm2, and then the yield decreased as the planting density increased.4) The high yield physiologic and biochemical characters were also analyzed.①The photosynthetic capacity of sandwich straw in the whole growth period was high, and so was the accumulation of mass production. The leaf index, chlorophyll content, photosynthetic potential and net assimilation rate were 4.8%, 33.9%, 17.0%, and 23.3% higher than the control. The T / R value of sandwich straw was high in the prior period, low in the mid-term and high in the later period.②The Sandwich straw of potato activity of ribulose-1,5-bisphosphate carboxylase, Mg-ATPase and Ca2+-ATPase were generally higher than in control. There enzymes were 37umol/mg.min, 235.4umol/mg.min and 454.7 umol/mg.min in the 75 days ,60 days and 75 days after sowing, but for glycolate oxidase and peroxidase lower than in control.③In the whole growth period, the nitrogen assimilation enzymes and nitrite reductase activity of sandwich straw potato were higher than in control. Especially in the 60 days after sowing, the nitrogen assimilation enzymes and nitrite reductase were 166.0% higher than the control.④The root activity was also 30.0% higher than the control. The absorption regularity of K was strong and 94% K needed was from soil. The vigorous stage of the absorption of K occurred during the 14d before squaring to the 15d prior to maturation. The absorption of K was stopped during the 15d prior to maturation to the maturation.⑤Sandwich straw model was beneficial to the accumulation of praline, which for different varieties were significantly higher than the control. But the MDA content of leaf of sandwich straw was lower than the control. The activity of SOD, CAT and POD appeared increasing trend with different degrees. The sandwich straw model could reduce the harm to the cell membrane.⑥The content of GA and ABA and the ratio between them appeared the same trend during the period of formation of tuber. And the increasing of ABA and the decreasing of GA were the important conditions for the tuber. But the ratio of ABA and GA played more important role in the formation of tuber. When the ratio of ABA and GA was more than 50, it was the elongation stage for creeping stem, and the tuber started to form when the ration less than 26. The ratio was at low level in the stage of tuber formation. Compared to the control, the ABA and GA content and their ratio were much more reasonable. Therefore, sandwich straw model was beneficial for the tuber formation.5) The soil environment with sandwich straw had been researched.①Sandwich straw could raise the content of soil bacteria, including nitrogen-fixing bacteria, fungi, actinomycetes, ammonification bacteria, nitrite bacteria, bacterial cellulose, and it could decrease denitrifying bacteria.They were markedly higher than the control. Especially in the 45 days after sowing, Sandwich straw soil bacteria, nitrogen-fixing bacteria, fungi, actinomycetes, ammonification bacteria, nitrite bacteria, cellulose have reached a significant level.②Sandwich straw cultivation can effectively improved Soil enzyme activity compared to control. For example, catalase, cellulase, invertase, and alkaline phosphatase activity, but for urease sandwich straw was lower than the conventional cultivation.③Sandwich straw could increase the soil temperature. The soil temperature in the soil layer of 10cm and 20cm in the whole growth period were generally higher than the control.6) According to the results of years of research and combined with the actual production, the technological regulation of sandwich straw model for potato in Fujian had been worked out.
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