Studies On The Standardized Plant Key Technical Of Dry Stress Seedling Nursing And Transplantation Of Paddy Rice Of NingXia

In this project .integrating with Ningxia actual paddy rice production, a research was undertaken to solve the faced outstanding problems and improve Ningxia paddy rice production through studying on the method for appropriate seedling nursing based on the cultivation of dry stress seedling nursing and thinning transplantation in the field and the field trials for the suitable planting density and the technical guidseelings for standardizd paddy rice cultivation .the main study outcomes were as follows: 1.The seeding date and seeding quantity were the proponent factors in determination of the growth of seedling and of rice yields .To raise vigor seedling was started with early seedling nursing and thin seeding in the field nursery .Vigor seedlings were crucial to high fields of paddy rice .One of the agronomic methods for predicting the yield to be over 650kg/666.7 m~2(with the probability more than 95%).was that the seeding date should be in between 1-10 April and the seeding quantity in field nursery ranged from50-160g/m~2.2. The relationship between seeding quantity in field nursery of seedlings transplanted by hand and the vigor of growth of seedling and its yielding .The seeding quantity of seedling at low level was associated with well vigor seedlings and after transplantation the yielding got higher and seeding quantity of seedlings at high level the yielding was low after transplantation At present the paddy rice production with transplanting by hand ,the seeding quantity in field nursery should be kept less than 220g/m~2.3. The amount of seeding in field nursery by machine had obvious impacts on the growth vigor of seedlings .The relatively small amount of seeding per unit area made a good effect ,and it was in flavor of keeping high living rate after transplanting and the index such as heading stage and yielding were also well .In consideration of actual production conditions it was good for the amount of seeding by machine being 670g—780g/m~2 .4.The primary studies shows that under the dry stress nursing of seedlings conditions concluded that the density of transplanting in field of was 50,000/666.7 m~2; the spacing of 30 ×13 in between rows -and holes cm and 3 seedlings per hole ,this density of planting under the present production conditions, was an appropriate option, with which the tiller potential could be brought into full play ,and individual plant developed fully ,and the structure of whole plants community was rational .It aimed at strong then the vigor of individual and promoting the growing of field plants community as a whole, and obtaining the big spike and the crop mode of finally realizing the high yielding.S.The N fertilizer application rate under the practice of dry stress seedling nursing and this transplantation shows that under the thin transplanting conditions the yielding could reach the highest with an application of 15 kg pure N per 666.7 m~2.the marginal yield increased along with the increase of application of N fertilizer ranging between 10 and 15 kg .The answers from the regression equation explained that the rate of application of N fertilizer with the highest level of yield was 15.93 kg,the optimum application of N fertilizer being 14.49 kg. With the increase of application of N fertilizer the tiller could be improved markedly .When and as the application of 15 kg N fertilizer followed ,the effective tiller went to the highest ,and the structure of plant community in the field as a whole turned to rational ,individuals grew well and the yielding related three key factors went into balance.6.The field trails for base fertilizers application based on the cultivation of dry stress seedling nursing and thin transplanting showed that the base fertilizers had better be dressed deep into the whole plough horizons and the reached maximum yield was up to 749.6 kg .The reasons for the high yielding were concerned with an application of fertilizers deep in plough horizon ,by which the fertilizers dispersed into lower soil layers and therefore the rate of utilization became into high level that satisfactorily met the nutritive requirements of plants during their growth of life .therefore in resulted in the enlarged plant community in the field per unit area ,and the increased numbers of harvested spikes improved growing conditions of individuals plants and large heads and raised numbers of seed grains.