黄土高原不同栽培模式下春玉米生理生态效应与生产潜力估算

ISWC OpenIR > 水保所知识产出(1956---)

	黄土高原不同栽培模式下春玉米生理生态效应与生产潜力估算
	刘毅
学位类型	博士
导师	李世清
	2009
学位授予单位	中国科学院研究生院
学位授予地点	陕西
学位专业	生态学
摘要	本论文通过两年不同栽培处理田间实验，对Hybrid-Maize玉米高产模型在黄土旱塬雨养、地膜覆盖及补充灌溉等栽培模式下的适应性进行验证，并就不同栽培模式对旱地玉米农田土壤水分、土壤温度、土壤呼吸以及玉米生理生态指标的影响进行深入研究，以期阐明黄土旱塬春玉米产量形成主要限制因子及产量潜力。研究结果对指导黄土高原旱地春玉米高产高效栽培体系建立具有一定科学及应用意义。研究获得以下主要结论：1. 黄土旱塬春玉米不同栽培模式显著影响作物生长发育动态、产量及环境资源利用。不同栽培模式下，玉米生殖生长时间所占比例与玉米产量具有相同表现规律，均表现为，补充灌溉 > 地膜覆盖 > 雨养 > 秸秆覆盖，补充灌溉及地膜覆盖均表现出显著的增产效果，从先玉335及沈单10两个品种平均看，与雨养相比，2007和2008年地膜覆盖籽粒分别增产19.0%和27.0%，补充灌溉分别增产27.2%和32.1%，而秸秆覆盖玉米明显减产；不同栽培模式对春玉米群体生物量累积具有明显影响，表现为地膜覆盖前期生物量累积速度较快；而补充灌溉与其相反，在玉米进入生育中、后期，干物质累积速率开始迅速增加，并最终超过地膜覆盖处理；叶面积指数（LAI）与不同栽培模式比较密切，在整个生育期内补充灌溉处理叶面积指数明显高于其它处理，特别是到在玉米生育后期，补充灌溉不仅显著增加玉米叶面积指数，同时也延长了玉米叶片生理功能的时间。地膜覆盖和补充灌溉在玉米生殖生长时期植物冠层截获的光合有效辐射（PAR_i）、大气积温（GDD_Air）和土壤积温（GDD_Soil）显著高于雨养栽培，与产量具有相同的表现规律，说明玉米在生殖生长时期冠层对光合有效辐射的截获以及大气和土壤积温的累积对产量形成具有重要作用。2. Hybrid-Maize玉米模型在指导黄土旱塬春玉米高产栽培上具有较好应用前景，同时表现出较好模拟效果，总生物量、秸秆生物量和籽粒产量模拟值与实测值间具有极显著线性相关性。黄土旱塬区多年光温生产潜力和气候生产潜力因品种不同有所差别，对多年平均光温籽粒和总生物量生产潜力，紧凑型玉米品种分别为13.25和22.45 t·hm^-2，平展型玉米品种分别为12.32和20.62 t·hm^-2，年际变化小；对多年平均气候籽粒和总生物量生产潜力，紧凑型玉米品种分别为11.97和19.94 t·hm^-2, 平展型玉米品种分别为11.37和18.63 t·hm^-2，年际波动大。Hybrid-Maize玉米模型不仅适用于黄土旱地塬补充灌溉春玉米栽培，同样也适宜育雨养及地膜覆盖栽培。Hybrid-Maize模拟结果同时表明，黄土旱塬春玉米产量潜力挖掘的主要途径应集中在提高密度和有限降水高效利用方面。3. 黄土旱塬春玉米不同栽培模式不仅影响土壤水分动态变化及土壤剖面贮水量，也影响春玉米水分吸收规律。土壤水分动态变化不仅呈明显季节性变化，且与栽培模式密切相关。表层（0~20cm）平均土壤含水量表现为秸秆覆盖 > 补充灌溉 > 地膜覆盖 > 雨养，且土壤贮水量（0~2m）以秸秆覆盖和补充灌溉显著高于雨养和地膜覆盖栽培。玉米生长季耗水量以苗期阶段最少，穗期阶段次之，花粒期阶段最多，其中抽雄吐丝期对水需求最为强烈，各处理耗水强度表现为补充灌溉>雨养>地膜覆盖>秸秆覆盖；不同栽培模式春玉米水分利用效率具有一定差异，地膜覆盖水分利用效率显著高于雨养栽培模式，而补充灌溉籽粒水分利用效率与灌溉量有密切关系。4. 黄土旱塬地区不同春玉米栽培模式不仅影响土壤温度动态变化，而且也影响玉米生长发育和对土壤热量资源利用。不同栽培模式下土壤温度变化呈明显季节性变化特征，各栽培模式均以5 cm土壤温度变化幅度最大，随着土层深度增加，土壤温度的变化幅度呈递减趋势；地膜覆盖具有明显的增温效应，而秸秆覆盖具有明显的降温效应；玉米不同生育阶段土壤积温，以出苗阶段土壤积温最少，生殖生长阶段次之，营养生长阶段最多；不同栽培模式对春玉米不同生长阶段的土壤积温效应不同，表现为地膜覆盖在出苗阶段土壤积温较低，补充灌溉在营养生长阶段土壤积温较低，雨养处理在生殖生长阶段土壤积温较低，以上结果说明，在黄土旱塬地区，不同栽培模式不仅影响土壤温度动态变化，也影响玉米生长发育和对土壤热量资源利用。5. 黄土旱塬地区，玉米生长和栽培模式不仅影响土壤呼吸速率，也影响到土壤呼吸与土壤水温因子间的相互关系。黄土旱塬春玉米农田土壤CO₂排放通量日变化特征为不对称单峰曲线，其最大值和最小值分别出现在10:00~16:00时之间和4:00时左右，土壤温度主要控制着土壤呼吸日变化。在玉米生长季中，4种不同玉米栽培模式土壤CO₂排放通量季节变化型式基本一致，呈单峰曲线变化规律，各处理土壤CO₂排放通量均以玉米抽雄吐丝期较高，在苗期和收获期排放量较低。不同栽培模式土壤CO₂排放通量均值差异明显（p<0.05），表现为覆膜（3.980 μmol·m^-2·s^-1）>秸秆覆盖（3.464 μmol·m^-2·s^-1）>灌溉（3.157 μmol·m^-2·s^-1）>雨养（2.371 μmol·m^-2·s^-1）>裸地（1.934 μmol·m^-2·s^-1）；随玉米生育期变化，土壤呼吸主要影响因子也发生变化，在生长季初期和末期主导影响因子是水分和温度；而在生长季中期，根系可能为主导因素，但这仍需更细致的研究。6. 补充灌溉和地膜覆盖栽培通过改善玉米光合同化作用而显著影响玉米产量。各栽培模式玉米叶片净光合速率（Pn）、气孔导度（cond）、蒸腾速率、Fv/Fm值以及叶绿素荧光综合性能指数（PI）在玉米生育期表现出相似的变化规律，拔节期到抽雄吐丝期较大，在玉米生育后期，各指标均出现不同程度下降趋势。先玉335和沈单10光合速率和叶绿素荧光综合性能指数均表现为补充灌溉和地膜覆盖明显高于雨养和秸秆覆盖，与不同栽培模式下玉米产量表现基本一致。7. 基于雷达图对各栽培模式进行的综合评价表明，在不同栽培模式中，补充灌溉各评价指标值均为最大，评分结果所构成的多边形向外明显扩张，但土壤温度评价值靠近圆心，说明补充概括在改善土壤温度方面表现出明显劣势；地膜覆盖处理在改善土壤水温过程方面的作用突出，水分利用效率较高，土壤呼吸强，土壤平均温度和积温也具有较高水平，呈现平衡发展态势；秸秆覆盖栽培模式下土壤贮水水平最高，但其它评价指标均低于平均水平；雨养栽培各项评价指标均较低，评价结果构成的多边形向圆心明显收缩。说明雨养和秸秆覆盖栽培的高产能力较弱。利用雷达图面积及周长进行的定量表征结果与其定性描述一致。8. 综合以上结果认为，黄土旱塬补充灌溉及地膜覆盖仍然是保证玉米高产的较好栽培模式，如果从节约水资源考虑，应首选地膜覆盖栽培。
其他摘要	Field management can notably influence crop production under dryland farming in semiarid areas. Different management factors such as suitable hybrids, plant nutrition, soil moisture, temperature, weed control, optimum plant population density (PPD), and cultivation practices are important to achieve desired grain yield of maize (Zea mays L.). Despite the availability of modern hybrids and better agronomic practices, there existed large gaps between attainable yield of maize grown with recommended practices and potential productivity on the Loess Plateau. A field experiment was conducted for 2 years in Changwu, Shaanxi (35.2°N and 107.8°E). The field cultivation practices tested were: supplementary irrigating (SI), rain-fed (RF), plastic film mulching (FM), corn straw mulching (SM). The objective of this study were: (i) to validate of the Hybrid-Maize model in the maize production system and simulate the potential productivity of maize on the Loess Plateau, (ii) to determine the most important management yield-limiting factor(s) on maize grain production. The main results were showed as follow:1. FM could make maize developmental stages occur earlier. Time proportion of reproductive stages and maize grain yield for different cultivation practices was ranked as follows: SI > FM > RF > SM. SI and FM could increase grain yield significantly. In 2007 and 2008, SI increased the grain yield by 27.2 % and 32.1 %, respectively, compared to RF, the grain yield increase by 19.0 % and 27.0 % for FM. The promotion effect of FM treatment on maize growth and development was bigger at the earlier stage of maize growth, while that of SI treatment mainly at the middle and later stages of maize growth. SM treatment of maize got much less grain yields in 2008. Conversely, irrigation can be considered a positive disturbance that increases the leaf area index (LAI) of the semiarid land area, changes the energy balance of the land surface, and can result in increased ecosystem carbon accumulation.2. The Hybrid-Maize model had a good simulation effect on the Loess Plateau. Correlation analysis indicated that there was a highly significant correlation between simulated data and observed data of total aboveground dry matter, stover dry matter and grain dry matter, The compact-typed maize species of photosynthetic-temperature potential productivity on the Loess Plateau was 13.25 t·hm^-2for grain yield and 22.45 t·hm^-2 for total biomass, the flat-typed maize species was 12.32 t·hm^-2for grain yield and 20.62 t·hm^-2for total biomass. The annual variation of photosynthetic-temperature potential productivity was low. The compact-typed maize species of climate potential productivity on the Loess Plateau was 11.97 t·hm^-2for grain yield and 19.94 t·hm^-2 for total biomass, the flat-typed maize species was 11.37 t·hm^-2for grain yield and 18.63 t·hm^-2for total biomass. The annual variation of climate potential productivity was strong. We conclude that the yield potential exploration of maize on the Loess Plateau was dependent mainly on improving planting-density and soil water condition, therefore, the Hybrid-Maize model has good application value on guiding maize high yield cultivation.3. The soil moisture is not only closely concerned with the seasons but also associated with different cultivation practices. Average soil water contents of upper soil layer (0~20cm) ranked as SM > SI > FM > RF, and the value of two former treatment significantly are greater than that of the later two. The evapotranspiration (ET) of soil are relatively high in tasseling and silking stage of maize but relatively low in maize seedling and physiological maturity stage. The ET for different cultivation practices over the growing season was ranked as follows: SI > RF > FM > SM. The Water use efficiency (WUE) was showed was different for the different cultivation practices. FM were significantly greater than RF. However, the WUE was closely related to the amount of irrigation for SI treatment.4. Different cultivation practices showed different effects on soil temperature. For each treatment, with increasing depth, the diurnal soil temperature range narrowed. However, a rather similar seasonal variations pattern for temperature occurred at different depths in the soil. Growing degree-days of soil (GDD_soil) in the Vegetative Stages comprised the greatest proportion of the whole maize’s growing season, followed by GDD_soil in reproductive stages, while planting to emergence stages had the lowest proportion. The FM soil compared to unmulched treatments (SI and RF) consistently had significantly higher temperature (P≤0.05) during the crop’s growing season, FM increased the soil temperature by about 2 °C. On the other hand, SM soil when compared with FM and unmulched treatments (SI and RF), recorded low temperature at all growth stages. No significant differences in soil temperature were recorded among RF and SI treatments at every the soil depths.5. Soil surface CO₂ flux was determined with a LI-8100 Automated Soil Flux System in 2008. Diurnal soil CO₂ flux showed a single peak between 12-00 h and 16-00 h, and reached a minimum in the early morning, at about 4-00 h. During the crop’s growing season, soil CO₂ flux increased during the rapid vegetative growth stages, reached its maximum during the peak reproductive stages, and then declined as the plants senesced. Time series analysis showed that the temporal dynamics of the CO₂ flux were more closely related to air temperature than to soil temperature; this may be because a substantial portion of the CO₂ originated from surface residues. The time-averaged mean soil CO₂ flux for different cultivation practices over the growing season was ranked as follows: FM (3.980μmol·m^-2·s^-1) > SM (3.464μmol·m^-2·s^-1) > SI (3.157μmol·m^-2·s^-1) > RF (2.371μmol·m^-2·s^-1) > bare ground (1.934μmol·m^-2·s^-1). Different cultivation practices affected plant and microbial activities, and soil hydro-thermal conditions, and caused different patterns of soil surface CO₂ flux in spring maize fields on the Loess Plateau.6. Different cultivation practices showed different effects on physiological and ecological characteristics. For each treatment, Photosynthetic rate, Conductance to H₂O, Transpiration rate, Fv/Fm, and Chlorophyll fluorescence performance index parameters showed a rather similar seasonal variations pattern, the results show that these index increased from the jointing to the tasseling stage, and reached its maximum around the tasseling and silking stages; it then decreased dramatically during the ripening stage. Average Photosynthetic rate and Chlorophyll fluorescence performance index ranked as SI > FM > RF > SM, and the value of two former treatment significantly are greater than that of the later two.7. A comprehensive evaluation method based on radar graph for the appearance of different cultivation practices was proposed. The result showed that SI on almost all indexes of the evaluation values are maximum except at the soil temperature, the polygon which posed by SI showed obvious outward expansion, but in soil temperature it has a distinct disadvantage. FM on soil moisture and temperature process had highlight level, higher WUE, stronger soil respiration, and soil average temperature and GDD_soil also had relatively high level, it is a more balanced development. SM had the highest soil water storage, but other evaluation indexes are below average. The evaluation of RF treatment indexes were low, this indicated the limited capacity of high-yielding for RF. 8. These results show that SI and FM were still better cultivation practices to ensure high-yield of maize on the Loess Plateau. However, we should prefer FM which considered from the conservation of water resources
文献类型	学位论文
条目标识符	sbir.nwafu.edu.cn/handle/361005/4112
专题	水保所知识产出(1956---)
推荐引用方式 GB/T 7714	刘毅. 黄土高原不同栽培模式下春玉米生理生态效应与生产潜力估算[D]. 陕西. 中国科学院研究生院,2009.