| 题名 | 膜下滴灌条件下棉花生理生态特性研究 |
| 作者 | 方怡向 |
| 学位类别 | 硕士 |
| 答辩日期 | 2007 |
| 授予单位 | 中国科学院．新疆生态与地理研究所 |
| 导师 | 赵成义，中科院新疆生态与地理研究所 |
| 关键词 | 膜下滴灌 |
| 其他题名 | Study on the Characteristics of Cotton’s (Gossypium hirsutum L) Phys-ecology under the condition of Drip Irrigation under Mulched |
| 中文摘要 | 利用PTM-48研究膜下滴灌条件下棉花叶片的光合、蒸腾特性，结合叶面积指数的时间序列动态函数进行模拟计算，研究膜下滴灌条件下棉花蒸腾耗水规律、计算棉花全生育期的蒸腾耗水、光合产物积累；通过分层分段挖掘法研究不同滴灌量条件下棉花的根系分布规律；通过测定不同滴灌量条件下棉花各器官生物量探讨膜下滴灌条件下水分对棉花生物量的积累与分配的影响，力求寻找既能节约用水又不影响棉花产量和品质的最优灌水量。基于以上研究得到如下结论：膜下滴灌条件下棉花净光合速率日变化为单峰型曲线，其峰值出现在12:00～16:00之间，无光合午休现象；棉花叶片蒸腾速率日变化整体上也呈单峰型曲线变化，峰值出现时间与净光合速率峰值出现时间基本一致，苗期叶片蒸腾速率明显大于其它生长期；随着棉花的生长发育，光饱和点和光补偿点均呈先升后降的变化趋势，开花期光饱和点及光补偿点最高；表观量子效率基本呈下降趋势，但在铃期较开花期出现小幅增加；叶片水分利用效率日变化呈现多样化，早晚各出现一个峰值；日平均水分利用效率呈先升后降趋势，蕾期日平均水分利用效率最高; 暗呼吸速率在开花期最高，吐絮期最低。棉花叶片日均WUE 在苗、蕾期变化幅度较小，7月初（67 d）到8月20日(117 d)左右，棉花叶片日均WUE 变化幅度较大，从8月21(118 d)日以后，WUE 呈明显下降趋势。随着棉花的生长，叶片日均净光合速率、蒸腾速率呈下降趋势，每公顷棉田日均蒸腾耗水、日均光合固定CO2量呈抛物线型变化趋势；在整个棉花生长期内，每公顷棉田蒸腾耗水为2909.67 m2 左右，固定CO2量约为42.16 t, 理论合成生物量28.75 t，实测生物量14.49 t，光合产物转换为生物量的转换系数为0.504，每公顷理论产棉潜力6.52 t，测产产棉6.56 t,实际产量5.57 t。 通过分层土柱挖掘法，研究膜下滴灌条件下不同滴灌量棉花 (Gossypium hirsutum L.)根系的分布特征。结果表明：直径＞1mm的粗根只分布在40 cm 以上的土层；随着土层深度增加，棉花根系生物量逐渐减少；但随着滴灌量减少，土壤深层根系生物量有增加趋势。不同处理根系生物量的分布与土层深度呈显著的负指数关系、但不同滴灌处理的棉花细根生物量、根长、根表面积在土壤中垂直分布都呈单峰型曲线变化规律；随灌溉量减少，棉花根系消弱系数β（root extinction coefficient）呈增加趋势。用单因素方差分析（One-Way ANOVA）法分析不同滴灌量处理条件下棉花各器官生物量及其所占比例的差异性，结果表明：不同滴灌量处理棉花叶生物量及占比例、单株叶片数有显著差异，而不同处理间单叶生物量差异不显著；不同处理间桃生物量、 结桃数、单桃干重无显著差异；不同水分处理下的棉花总生物量，地上部分生物量主茎、枝条生物量无显著影响，但不同水分处理条件下，棉花根系生物量、根冠比具有显著差异； 不同水分处理下棉花单棉干重，平均单株产棉、平均亩产均无显著差异。不同的水分条件影响棉花生物量的积累和分配，但适当的水分胁迫，不会影响棉花产量，棉花整个生长期内，生理需水2954.83 m3，处理三（2975.36 m3 /hm2）产量最高，耗水量较低，与棉花的生理耗水量非常接近，是一个比较适宜的滴灌量。The characteristics of net photosynthesis and transpiration of cotton’s (Gossypium hirsutum L.) leaves under the condition of drip irrigation under mulched were studied by PTM-48 in this paper. In terms of the dynamic changes of LAI, a simulated computation was done to study the rules of cotton’s water demanded for transpiration and calculate the amount of cotton’s transpiration water demanded during the whole growth stage as well as the characteristics of cotton’s photosynthesis accumulation under the condition of drip irrigation under mulched. The characteristic of cotton root distribution under different drip irrigation conditions under mulched was studied by layered divided digging methods. By testing the dry biomass of cotton’s different organ under different drip irrigation amount, the effect of water on the accumulation and distribution of cotton’s photolysis production was analyzed. We want to figure out the optimum irrigation amount and irrigation system, which can not only save water but also have no effect on cotton production and quality. The following conclusions have been drawn based on the above research. The daily dynamic curve of cotton’s net photosynthesis rate (Pn) and transpiration rate (Tr) in the whole growth stage is a single-peak valued curve and the peak value occurred between 12:00 am and 4:00 pm. No photosynthesis midday depression appeared during cotton’s whole growth stages. The Tr of the leaves is clearly higher during the seedling stages than the other growth stages. With the cotton’s growth and development, both the Light Compensation Point (LCP) and the Light Saturation Point (LSP) increase before flower stage and then get decreased; the average Apparent Quantum Yield (AQY) is decreasing as the cotton’s growth on the whole but the average AQY is a little more in the Boll stage than in the flowering stage. The saturated net photosynthesis (Pn sat ) shows the decreasing trend; the daily dynamic curves of Water Use Efficiency (WUE) of the leaves at different growth stages is diverse and the average WUE rises from seedling stage to budding stage then falls. Dark respiration rate is the highest in the flowering stage and the lowest in the boll-opening stage; the changing range of cotton leaves daily average WUE is diminishing during the seeding and bud stages. From the beginning of July (67 d) to August 20th (117 d), the changing range of leaves daily average WUE is comparatively larger than other stages and WUE obviously tends to decline from August 21st (118 d) on. With the cotton’s growth, the leaves’ daily average net photosynthesis rate as well as transpiration rate tends to decline and the daily average transpiration water demanded per hectare cotton field and the daily average CO2 amount fixated by leaves’ photosynthesis tend to change as a parabola. During the full cotton growth stage, the transpiration water demanded of per hectare cotton field is about 2909.67 m3, the CO2 amount fixated by leaves’ photosynthesis is about 42.16 t, one hectare’s cotton can synthesize 28.75t biomass theoretically, and the actual test biomass is 14.49 t. The transitional coefficient from the photosynthesis product to biomass is 0.504, the theoretically potential cotton production per hectare is 6.52t, while the tested cotton production is 6.56t and the actual cotton production is 5.57t. The distributional characteristics of cotton root (Gossypium hirsutum L) in different irrigation amounts were investigated by the layered digging method in this study. The result indicated that: The coarse root whose diameter is bigger than 1 mm is only distributed in the soil layer above 40cm; with soil depth increased, root biomass gradually decreased in different irrigation amounts. But there is an increased trend in deep-seated root biomasses only with irrigation amounts decreased. Underground biomass has a significant negative logarithm relation with soil depth in different irrigation amounts. Root length and root surface area have the same changeable rule with different irrigation amounts. With depth increased, roots length and roots surface area changes as a single peak curves with the increase of soil depth. Root extinction coefficient of cotton in different irrigation amounts was calculated by Sigma Plot. The result indicated: With irrigation amounts decreased, root extinction coefficient of cotton shows an increased trend. The difference of various organs biomass as well as its ratio to the total biomass of single individual cotton under the different drip irrigation conditions was analyzed by One-Way ANOVA, which indicates that: the leaves dry weight and its proportion and the number of single individual cotton have a significant difference. However, the single leave’s biomass doesn’t have a significant difference under different drip irrigation amount. The cotton’s root biomass and the ratio between root and cap under different drip irrigation conditions have a significant difference. But there is no significant difference on the aspect of the average individual cotton production and the average production per hectare among the four treatments. The study suggests that different water supply can change the accumulation and distribution of cotton’s biomass; but the proper water stress perhaps have no effect on cotton production. In addition, during cotton’s growth stage, the third measure of the study (the irrigation is 2975.36 m3 per hectare) can make the largest production and the water consumed is comparatively lower. It’s very close the amount of physiology water demanded, it is a comparatively proper irrigation amount. |
| 语种 | 中文 |
| 学科主题 | 作物栽培学与耕作学 |
| 公开日期 | 2010-11-12 |
| 页码 | 共69页 |
| 内容类型 | 学位论文 |
| 源URL | [http://ir.xjlas.org/handle/365004/7908]  |
| 专题 | 新疆生态与地理研究所_中国科学院新疆生态与地理研究所(2010年以前数据) |
| 推荐引用方式 GB/T 7714 | 方怡向. 膜下滴灌条件下棉花生理生态特性研究[D]. 中国科学院．新疆生态与地理研究所. 2007. |
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