【摘要】 本研究设置7个梯度施氮量处理，分别为不施氮肥对照（CK）、施氮量50 kg/hm²处理（T1）、施氮量100 kg/hm²处理（T2）、施氮量150 kg/hm²处理（T3）、施氮量200 kg/hm²处理（T4）、施氮量250 kg/hm²处理（T5）、施氮量300 kg/hm²处理（T6）,分析施氮量对滴灌水肥一体化模式下玉米生长发育和土壤生物学特性的影响。结果表明，随着施氮量的增加，玉米叶片气孔导度、胞间CO₂浓度、净光合速率、产量、根系活力、土壤脲酶活性、土壤磷酸酶活性、土壤蔗糖酶活性、土壤过氧化氢酶活性均呈先升高后降低的变化趋势。表明适宜施氮量可通过增强玉米光合作用、提升土壤酶活性及改善土壤理化性质等途径显著提高玉米产量。在施氮量为250kg/hm²时，玉米产量最高。适量施氮可提高土壤微生物生物量碳（MBC）、土壤微生物生物量氮（MBN）、土壤微生物生物量磷（MBP）含量，其中MBC含量与玉米单株重、穗重、秸秆重、籽粒重、产量、根长呈极显著正相关（P<0.01）,与株高、茎粗、叶绿素相对含量、单株穗数呈显著正相关（P<0.05）。MBN含量与百粒重呈显著负相关（P<0.05）。微生物生物量磷（MBP）含量与根体积、根系活力呈极显著正相关（P<0.01）,与秸秆重呈显著正相关（P<0.05）,与根相对表面积呈显著负相关（P<0.05）。表明MBC含量、MBN含量与玉米地上部生物量积累和产量形成密切相关，MBP含量与根系形态建成密切相关。本研究结果为滴灌水肥一体化模式下玉米氮肥管理提供了理论依据。更多还原

【Abstract】 In this study, seven gradient nitrogen application rate treatments were set up, namely no nitrogen fertilizer control（CK）, nitrogen application rate of 50 kg/hm²（T1）, 100 kg/hm²（T2）, 150 kg/hm²（T3）, 200 kg/hm²（T4）, 250 kg/hm²（T5）, and 300 kg/hm²（T6）. The effects of nitrogen application rates on maize growth and development and soil biological properties under the drip irrigation and fertigation integration mode were analyzed. The results showed that with the increase of nitrogen application rate, maize leaf stomatal conductance, intercellular CO₂ concentration, net photosynthetic rate, yield, root activity, soil urease activity, soil phosphatase activity, soil sucrase activity, and soil catalase activity all showed a trend of first increasing and then decreasing. The findings revealed that an appropriate nitrogen application rate significantly increased maize yield by enhancing maize photosynthesis, improving soil enzyme activity, and optimizing soil physical and chemical properties. The highest maize yield was achieved when the nitrogen application rate was 250 kg/hm². Appropriate nitrogen application could increase the contents of soil microbial biomass carbon（MBC）, soil microbial biomass nitrogen（MBN）, and soil microbial biomass phosphorus（MBP）. Among them, MBC content was extremely significantly positively correlated with maize plant weight, ear weight, straw weight, grain weight, yield, and root length（P<0.01）, and significantly positively correlated with plant height, stem diameter, relative chlorophyll content, and number of ears per plant（P<0.05）. MBN content was significantly negatively correlated with 100-grain weight（P<0.05）. MBP content was extremely significantly positively correlated with root volume and root activity（P<0.01）, significantly positively correlated with straw weight（P<0.05）, and significantly negatively correlated with relative root surface area（P<0.05）. These results suggested that MBC and MBN contents were closely related to the accumulation of aboveground biomass and yield formation of maize, while MBP content was closely related to the formation of root morphology. The results of this study provide a theoretical basis for maize nitrogen management under the drip irrigation and fertigation integration mode.更多还原