The Study Of Regulating Effects Of NPK On Matter Accumulation And Yield Of Tartary Buckwheat

Buckwheat is one of the most important crops along the Great Wall in northern Shaanxi, enjoying a good reputation both at home and abroad, because of its better quality, good nutrition and health care effect, drought and barren resistance. But the area is the semi-arid area and characteristic of dry farming, with less rainfall and barren soil. For the long-term extensive cultivation and little or no fertilizer, the buckwheat has lower yield and output rate in this area, opposing a great impact on the development of buckwheat characteristic agriculture. Single factor randomized block design was used in the paper, in order to study effects of different N, P, K application contents on tartary buckwheat`s dry matter accumulation and transportation, main characters, yield, soil moisture and nutrients, to make clear the ties between the growth and development of tartary buckwheat with soil water and nutrients, then determined suitable N, P, K application contents, in order to provide theoretical support for cultivation techniques of high yield and quality of tartary buckwheat. From this study, we drew the following conclusions:1. The application of N, P, K increased the dry matter accumulation and transportation of tartary buckwheat, which were significantly affected by different application contents of N, P, K in various stages of tartary buckwheat. Under the conditions of N3, P3, K2, the amount of leaf dry matter reached the maximum: respectively 5.215 g per plant, 7.245 g per plant and 3.097 g per plant; Under the condition of N4, P4, K3, the grain was the largest: respectively 6.249 g per plant, 7.080 g per plant,6.397 g per plant;The contribution rate to dry matte, the amount and the efficiency of total translocation all were the highest in the treatment of N4, P3, K4. Different application contents of N, P, K had various effects on contribution rate and dry matter synthetic efficiency; Stems made the most contribution to grain among the aboveground dry matter before flowering. Reasonably enlarged application contents of N, P, K could raise production mainly by increasing assimilate contribution rate after flowering.2. N, P, K application contents had significant effects on tartary buckwheat yield. When under the condition of N4, P4, K3, the yield was the maximum: respectively 47.23 kg/666.7m2, 45.89 kg/666.7m2, 37.78 kg/666.7m2 and significantly higher than that of the horizontal gradient of fertilization under different application contents. Applying different N, P, K contents significantly affected the agronomic traits of tartary buckwheat. The grain number per plan, the grain weight per plan and the 1000-grain weigh would increase with the increase of N, all of which increased at first and then decreased with the raising application of P, K, and achieved the highest level under the condition of N5, P3, K3.3. With the increase of applying N, P, K content, partial productivity and utilization efficiency of agriculture fertilizer would significantly decreased; The application of N, P, K, could reduce the content of lower layer soil water; The application of different contents of N, P, K had obvious effect on soil available NPK. The appropriate increase of N, K could raise the content of soil available nitrogen and potassium, while the application of P had no significant effect on soil available P content.