| In order to improve fertilizer use efficiency of oil sunflower further, researched and explored oil sunflower fertilizer regulation law in cracked.soil in Ningxia Pingluo. Selecting oil sunflower varieties T8221, discussed and studied nutrients accumulation, distribution law, the law of grain filling, NPK fertilizer efficiency and photosynthesis relations of oil sunflower deeply.The resulted that:1. Under condition of different fertilization treatments, plant height and stem diameter of oil sunflower was "S" type curve, and in line with "Logistics" curve model for 0.98 correlation coefficient or more. NP fertilizer treatment promoted plant height and stem diameter of oil sunflower obviously, up to129.99 cm and 24.65 mm with average, and higher 15.21% and 18.62% than the NPK fertilizer. Taking all fertilization treatments, the order of different proportion of fertilizer on plant height were P> N> K, the effect of stem diameter were N> P> K.2. Oil sunflower dry matter accumulation with different fertilization treatments was "S" type curve, and fit with "Logistics" curve model for 0.99 correlation coefficient or higher. NPK fertilizer treatment promoted dry matter accumulation of oil sunflower obviously, up to 259.19 g/plant, increasing 43.45% compared to CK. Taking all fertilization treatments, the order of nutrients with dry matter accumulation is:N> P> K.3. NPK promoted significantly for N uptake of and P2O5 with the whole growth period of oil Sunflower, up to 3.68 g/plant and 24.65 g/plant, increasing 75.79% and 0.93% compared to CK. Bio-organic fertilizer also has a significant effect on the absorption of plant N and P2O5 uptake. NP, NK and PK fertilizer treatments promoted function with N of P2O5 uptake next. Under different fertilization, the order on nutrient uptake cumulativewere N> P> K. Through the whole growing period, NP fertilizer enhanced Single Plant K2O nutrient absorption most significantly, increasing 93.90% compared with CK. NPK and bio-organic fertilizers is second, NK and PK fertilizers promoted relatively weak. In a word, impact of different NPK proportions to nutrient uptake cumulative single plant were as follows: N> P> K.4. Different fertilization had different effects on fatty acids of oil sunflower seed, the order of stearic acid content with different fertilizer treatments is N> P> K, the order of oleic acid content with different fertilizer treatments is N> P> K. Fertilizing reduced the linoleic acid content of sunflower oil, the order of linoleic acid content with different fertilizer treatments is N> P> K.5. Different fertilization treatments are conducive to improve oil sunflower biomass accumulation and seed yield. Under the conditions of NPK whole application, grain yield, biological yield and growth ratio is highest, bio-organic fertilizer enhanced grain weight significantly, while unfilled grain rate was the lowest with no potash (NP) treatment. For the regression equation, fertilizing increased grain weight, reduced the rate of unfilled grains, increased the accumulation of photosynthetic products, increased yield. The order is N> P> K.6. Under alkaline soil conditions, non-rectangular hyperbolic model had a high degree with net photosynthetic rate (R2> 0.99). Oil sunflower net photosynthetic rate, stomatal conductance and transpiration rate increased with photosynthetically active radiation significantly, after leveling, while intercellular CO2 concentration continues decreasing. Light compensation point and light saturation point were the range of 13.48 -29.22 μmol·m-2 ·s-1 and 1242.10-1663.32μ·mol·m-2 ·s-1, and the maximum net photosynthetic rate from 33.242 -46.279 μ·mol CO2·m-2·s-1. the order of net photosynthetic rate with different fertilizer treatments is N> P> K. |
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