完整的氮肥管理策略提高油菜產(chǎn)量,含油量和氮肥的高效利用

1、完整的氮肥管理策略提高油菜產(chǎn)完整的氮肥管理策略提高油菜產(chǎn)量，含油量和氮肥的高效利用量，含油量和氮肥的高效利用 Winter oilseed rape (Brassica napus L.) is the dominant oilseed crop in northern Europe. Generally, it requires high amounts of nitrogen (N) but is characterized by low N efficiency fertilizer. Consequently, there is a strong need to resume all

2、the relevant information on N in relation to cropping of winter oilseed rape and environmental impact to improve the efficiency of rape production. To enhance the productivity of winter oilseed rape cropping, integrated N-management strategies are needed including optimized N-supply due to varied cr

3、op rotations or fertilization, best soil and crop management practices.IntroductionIntegrated N-management strategies affecting N-efficiency in plant production (Wiesler et al., 2001a)Improving N-efficiency of winter oilseed rape will reduce the potential for environmental pollution and improve econ

4、omic returns. In terms of the environment, the crop should receive optimum doses of N to insure yield development and to avoid subsequent N-leaching from the soil .Definition of N-efficiencyLiterature to describe the agronomic and physiological range of Nefficiency referring to external and internal

5、 N-status N and yield formationThe life cycle of winter oilseed rape is divided into ten principalstages. The use of numerical keys is useful for timing of management operations. Definitions and codes of stages of development in oilseed rape .N and yield formationYield structure of winter oilseed ra

6、peInfluence of environmental factors on plantgrowth and N-efficiencyEnvironmental factorsSoil conditionsWater availabilityTemperatureRadiationAtmospheric CO2-concentrationIntegrated N-management strategiesCrop rotation Previous crops to winter oilseed rape Winter oilseed rape as previous cropCultiva

7、rAmount of N Predicting N-demand Rate of NForm of N-fertilizer Organic fertilization versus mineral fertilization Form of mineral N-fertilizerTechnique of N-applicationTiming of N-applicationIntegrated N-management strategiesCrop rotationSeed and grain yield (Mg ha1) of winter oilseed rape, winter w

8、heat, winter barley, pea and oat following different preceding crops (19882000, averaged over three husbandry treatments) (Christen, 2001)Crop rotationSeed yield of winter oilseed rape related to previous crop, fertilizer form and N-rate The result showed that winter oilseed rape following winter ba

9、rley achieved 3.72 Mg /ha compared to 4.10 Mg/ha after previous crop pea . Thus, there was a yield increase of approximately 10% by incorporating pea as previous crop.CultivarSeed yield of 12 winter oilseed rape cultivars related to N-rate Genotypes classified to seed yield with (240 kg N/ha) and wi

10、thout N-fertilizationAmount of NN-uptake at beginning of flowering, at maturity and during reproductive growth phase means of 12 winter oilseed rape cultivars related to N-rateFurther crop management practicesSoil cultivationSoil fertilizationSowing Plant protection Growth regulatorsHarvestDetermina

11、nts for N-efficiency in winter oilseed rape croppingConclusions1. Here we have shown that in oilseed rape production using improved N-management strategies will lead to substantial reductions of N-fertilization, representing up to 50% of fertilizer input thus, reducing N-balance surpluses tremendous

12、ly.2. Adjusted to site conditions prediction of N-demand, integration in crop rotation, utilization of N-efficient cultivars as well as improved timing, form and technique of N-fertilization are major determinants to increase seed yield and seed quality of winter oilseed rape and reduce N-losses to environment.3. In future, breeding should aim at high yielding semi-dwarf