【作者】 田育丰；

【导师】 张富仓；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2008， 硕士

【摘要】 石羊河流域位于甘肃省河西地区东部,属大陆性温带干旱气候,生态环境十分恶劣,地表水较为缺乏,地下水开采过度。农业的可持续发展依赖于水资源的合理利用,在开源难以维继的状况下,节水灌溉是今后农业可持续发展主要措施之一。本试验在甘肃省石羊河流域武威市沙漠公园试验站进行,研究了春玉米在不同的灌水、施氮条件下的生长、光合特性、叶水势的变化特性以及灌水和施氮对产量和水分利用效率的影响。试验设5个因素:施氮量（A）、苗期灌水（B）、拔节期灌水（C）、抽雄期灌水（D）、灌浆期灌水（E）;4个供水水平:337m³/hm²（1）、675m³/hm²（2）、1012m³/hm²（3）、1350m³/hm²（4）;4个施氮水平:75kgN/hm²（1）、150kgN/hm²（2）、225kgN/hm²（3）、300kgN/hm²（4）;各因素之间为正交组合L₁₆（45）,重复2次;播前一次性施入氮肥,每小区按560kg/hm²施入磷肥（普通过磷酸钙）,小区面积为5m×4m,共32个小区。研究结果表明,施氮量是影响玉米苗期叶面积和株高的关键因素,高氮和充分供水不利于玉米的生长。促进玉米苗期生长的最佳组合为A₂B₂。施氮量对玉米根系生长的影响均达到极显著水平。苗期灌水、拔节期灌水、抽雄期灌水、灌浆期灌水对根系生长的影响未达到显著水平。与当地施氮水平A₄相比,A₃水平、A₂水平、A₁水平玉米根重分别减少了4%、13.4%,31.3%。A₃水平比A₄少施氮肥75kgN/hm²,根重仅减少了4%。苗期灌水量水平为A₃时,玉米的根重最大;灌水量水平为A₁时,玉米根重量最小。施氮量和苗期灌水对玉米苗期光合速率的影响达到极显著水平,全生育期内玉米光合速率随施氮量的增加而升高,随灌水量的增加而增大。施氮量是影响玉米产量的最主要因素,各个因素对玉米产量的影响作用由大到小的位次依次是A>D>B>C>E,各因素对玉米产量的影响均达到极显著水平,与当地的施氮水平A₄相比,A₃、A₂、和A₁水平施氮比A₄水平分别减少了25%、50%和75%,产量分别下降了6.9%、12%和34.8%。为获得最大经济产量,建议玉米全生育期内各个因素组合模式为施氮肥225kg/hm²,苗期灌水1012m³/hm²,拔节期灌水1350 m³/hm²,抽雄期灌水1012 m³/hm²,灌浆期灌水337 m³/hm²。施氮量是影响玉米水分利用效率的最主要因素,其次是拔节期灌水,各因素对玉米水分利用效率影响作用的位次依次为A>C>B>D>E,获得最大水分利用效率的最优组合为A₄B₃C₂D₃E₁。0～100cm土层的硝态氮含量随施肥量的增加而增加。高氮处理在整个1m土层硝态氮含量明显高于其他处理,特低氮处理和低氮处理10～100cm土层的NO₃^--N没有明显的变化;中氮和高氮处理0～40cm土层NO₃^--N有轻微累积,40～60cm有明显累积,60～100cm有轻微的累积。更多还原

【Abstract】 Shiyang River Basin lies in the east of Gansu Hexi, which is continental dry climate, ecological environment is very poor. Surface water is shortage and groundwater is over exploited. Maintainable development of agriculture depends on rational exploitation of water resource; water-saving irrigation is one of main measures under the condition of water shortage. The experiment was conducted in the experimental station of Wuwei Desert Park, we laid emphases on the growth, photosynthesis characteristic, leaf water potential, yield and water use efficiency of summer maize under the condition of different water and nitrogen. Factor was supplied by five: nitrogen fertilizer （A）, seeding irrigation （B）, jointing irrigation（C）, heading irrigation （D）, filling irrigation （E）. Four nitrogen levels: 75kgN/hm² （1）, 150kgN/hm² （2）, 225kgN/hm² （3）, 300kgN/hm² （4）. Four water levels: 337m³/hm² （1）, 675m³/hm²（2）, 1012m³/hm²（3）, 1350m³/hm²（4）. The orthogonal portfolio was used in the experiment. Nitrogen fertilizer was fertilized one time before sowing, Phosphorus fertilizer （calcium superphosphate） was fertilized by 560kg/hm² in each district. The district area was twenty square metres; the experiment included a total of 32 districts. By study of one growth season, the result showed that nitrogen fetilizer was the the key effect factor of corn seedling leaf area and the plant height, the most appropriate amount of nitrogen was 75 kgN/hm², demand for water and nutrients was small in corn seedling, effect of appropriate water lack on the plant growth was not great, amount of 75 kgN/hm² could meet its growth need, excessive nitrogen fetilizer may burned seedlings, high nitrogen and full water was not conducive to maize growth. The ideal combination of promoting the corn seedlings growth was A₂B₂.Nitrogen fertilizer amount impacted on the corn roots growth reached a significant level. The seedling stage irrigation, jointing stage irrigation, tasselling stage irrigation, filling stage irrigation impacted on corn roots growth did not reach significant level. Compared to local nitrogen fertilizer level, the roots of A₃ level, A₂ level, and A₁ level were reduced by 4%, 13.4%, and 31.3% respectively, Compared with the A₄ level, nitrogen amount of A₃ level was decreased by 75kgN/hm², and root weight only decreased by 4%.The corn root weight was largest when seedling irrigation was A₃, and it was minimum when seedling irrigation was A₁.Nitrogen fertilizer amount and seeding irrigation impacted on the corn roots growth reached a significant level. Corn photosynthetic rate increased with the increasing of nitrogen and irrigation.The most important factor of effect on corn yield was nitrogen fertilizer amount, Effect of factors on the corn yield was different , the ranking followed by A>D>B>C>E, all factors impacted on the corn yield reached a significant level, compared to the A₄（ local nitrogen fertilizer level）, the nitrogen rate of A₃, A₂, A₁ were reduced by 25%,50%,75%;and corn yield was reduced by 6.9%, 12%, 34.8%.the proposed combination model was that: nitrogen fertilizer amount was 225kg/hm², seedling irrigation was 1012m³/hm²,jointing stage irrigation was 1350m³/hm², tasselling stage irrigation was 1012m³/hm², filling stage irrigation was 337m³/hm².The most important factor of affecting corn nitrogen water use efficiency was nitrogen rate, followed by the jointing stage irrigation, the factors order of affecting the corn water use efficiency（WUE）was A>C>B>D>E, Optimum combination of obtaining maize WUE was A_4B3_C2D₃E₁.NO₃^--N content of 0-100cm soil profile increased with increasing of nitrogen rate. NO₃^--N content of high-nitrogen treatment were significantly higher than that of other treatment. In 10-100cm soil profile, NO₃^--N content of lowest nitrogen and low nitrogen treatment didn’t obviously change; In 0⁴0cm and 60～100cm soil profile,NO₃^--N of moderate nitrogen and high nitrogen treatment accumulated obviously in 40 60cm soil profile slightly.更多还原