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The area of Changjiang River boasts the large area of further improvement of rapeseed production. At present, because of the ecological disadvantage in Changjiang River valley and the lack of research and application on cultivation techniques of high-yield and top-quality in rapeseed production, further improvement of rapeseed yield and quality is restricted. Therefore, according to the specific ecological condition in Changjiang River valley, we have chosen five factors in our test including variety, density, sowing date, supplement of nitrogen and phosphorus, and adopted the five-factor second-order regression with orthogonal, rotatable and central composite design. There are two types of test fields, direct sowing fields and transplant fields. Our test aims at finding ort the influence over rapeseed yield and quality by five factors, and building mathematic models about the relationship to analyze and optimize the mathematic models. So by the optimized mathematic models, we can find out optimized cultivation theory which can be applied in the area of Changjiang River. Our test results are as follows:1. So by analyzing the equation, the influence over rapeseed yield by five factors ranks as follows: Supplement of nitrogen (x3) > sowing date (x2) > supplement of phosphorus (x4) > density (x1) > variety (x5); and further deduction indicates: among linear terms, supplement of nitrogen (x3) exerts significant influence over rapeseed yield under 1% level, supplement of phosphorus (x4) and sowing date (x2) make significant influence over rapeseed yield under 5% level; among interactive terms, density (x1) and sowing date (x2) impose significant influence over rapeseed yield. By simulative optimization from the mathematic models built above, we have got 217 optimized composites from all 3125(5~5) composites of five factors under the control of the rapeseed yield ≥3000kg/hm~2. Therefore, we have got optimized cultivation measures about each variety in the test.1.loptimized cultivation measures about Huaza 6: density is 139000- 158000plants/hm~2, sowing date is September 18-20, supplemeny of nitrogen is 189.0-214.8kg/hm~2, and supplement of phosphorus is 130.5—142.7kg/hm~2;1.2optimized cultivation measure about Huaza 10: density is 133000-160000plants/hm~2,
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