【作者】 张云兰；

【导师】 王龙昌；

【作者基本信息】 西南大学 ， 生态学， 2010， 硕士

【摘要】 降水是高温伏旱区旱地农作系统的主要水资源。为了合理利用农业水资源、改善水分供需矛盾、提出调整农业水资源利用优化方案,达到降水资源高效利用的最终目标,研究旱作农田作物降水供需状况,开展旱地农作系统水分生态适应性评价,十分必要。本研究以农田作物种群优化和降水资源化为基本目标,根据调查资料和田间实验结果,以高温伏旱代表区域奉节、万州、沙坪坝为研究区,计算出重庆几种主要作物(小麦、玉米、红薯、马铃薯、胡豆、大豆、油菜)和主要种植模式(麦-玉-苕、胡-玉-苕、麦-玉-豆、薯-玉-苕、胡-玉-豆、油-玉-苕)的需水量,系统地分析在坡度0°、5°、10°、15°、20°、25°耕地上,三种降雨年型中,作物生长发育与降水分布的时序关系、主要作物和种植模式水分供需平衡与错位特征,并利用水分生态适应性数学模型进行评价,以期对西南旱作地区种植制度优化和生产技术改进提供科学指导。主要结论如下：(1)重庆高温伏旱区降水时空分布特征与有效降水量：重庆各年降雨量变化较大,且从1994年开始,这个波动有增大的趋势。平均年内降雨主要集中在5-9月四个月期间,占全年总降雨量的68.62%,其中7月降雨量最大。奉节地区三种降雨年型主要是由各年5-9月份的实际降雨量决定。丰水年5-9月的降水总量占全年降雨量的76.48%，平水年5-9月的降水总量占全年总和的67.34%,欠水年同期占全年总降雨量的64.39%；万州三种降雨年型各月降雨量的差异主要体现在7-9月,丰水年7-9月的降雨量占全年的54.16%，平水年7-9月的降雨量占全年的54.16%，欠水年这个时期的降雨量占全年的40.59%。沙坪坝三种降雨年型的年降雨量差异的最明显月份为7月,丰水年7月的降雨量占全年的38.45%，而平水年同期的降雨量仅占9.97%，欠水年更少为3.25%。同一地区、同一降雨年型的有效降雨量随着耕地坡度的增加而减少。5°、10°、15°、20°、25°坡耕地上的有效降雨量分别比0°耕地上减少4%、12%、20%、27和35%。(2)高温伏旱区旱地作物需水量与作物系数：三个研究区和北碚实验区的平均年参考作物蒸散量的大小顺序是奉节>北碚>万州>沙坪坝；平均各月的日均参考作物蒸散量呈抛物线分布,和年内各月气温分布相近,较大值出现在5-8月份。儿种主要单作作物整个生育期的作物系数大小排序为：红薯-马铃薯>大豆>胡豆>油菜>玉米>小麦；就同种单作作物而言不同研究区作物需水量的大小顺序为：奉节>万州>沙坪坝；就相同的复作模式而言,不同研究区作物需水量的大小顺序为：奉节>万州>沙坪坝；同一研究区不同复作模式需水量大小顺序为：油-玉-苕>胡-玉-豆>薯-玉-苕>麦-玉-豆>胡-玉-苕>麦-玉-苕。(3)高温伏旱区旱地主要作物和种植模式水分供需平衡特征：在同一个降雨年型里,不同研究区单作作物和复作模式的水分满足率都随着耕地坡度增加而减小。复作模式的生育期为整个生产年度,同一研究区里,几种复作模式的水分满足率大小和降水年型有关,其大小顺序是丰水年>平水年>欠水年。在平整的耕地上,奉节丰水年和平水年适宜的单作作物为红薯、玉米和大豆,欠水年没有最适宜的单作作物,可以选择较适宜的小麦和油菜。万州各降雨年型都适宜的单作作物较多,如玉米、马铃薯、胡豆和油菜。沙坪坝的主要单作作物在不同降雨年型的水分满足率都大于或等于1，所以可以根据实际需要配置作物品种。奉节只有丰水年适宜在坡度较小的耕地上种植麦-玉-苕、胡-玉-苕和麦-玉-豆。万州丰水年里可以在平整的土地上种植各种复作模式,平水年里适宜种植麦-玉-苕。沙坪坝平水年里适宜种植麦-玉-苕、胡-玉-苕和麦-玉-豆。(4)高温伏旱区旱地农作系统水分生态适应性规律：由单作作物生育期在三个研究区的水分生态适应性指数的大小和相对稳定性来看：沙坪坝>万州>奉节。将各种作物全生育期分为前期(Ⅰ)、发育期(Ⅱ)、中期(Ⅲ)、后期(Ⅳ)四个时期,分别分析了各生育期水分生态适应性指数。水分生态适应性指数偏小(小于0.9)的单作作物有：奉节地区的小麦在第Ⅱ生育期和全生育期水分生态适应性指数分别为0.85和0.84；玉米在第Ⅲ生育期为0.89；马铃薯生育期为0.85；胡豆在第Ⅱ、Ⅲ和全生育期分别为0.79、0.8和0.73；油菜在第Ⅱ和全生育期分别为0.77和0.75。万州地区的小麦在第Ⅱ生育期水分生态适应性指数为0.85；胡豆在第Ⅱ、Ⅲ和全生育期分别为0.81、0.8和0.89；油菜在第Ⅱ生育期为0.77。沙坪坝地区的胡豆在第Ⅱ生育期为0.89。复作模式在三个研究区水分生态适应性指数的大小顺序为：沙坪坝>万州>奉节。其中水分生态适应性指数偏小(小于0.8)的有：奉节地区的薯-玉-苕水分生态适应性指数为0.78；油-玉-苕为0.73；胡-玉-豆为0.75。(5)重庆高温伏旱区旱地节水抗旱的农业对策：针对高温伏旱区的伏旱发生频率高,持续时间长,降雨时空分布不均的特点,通过积极调整种植结构,调节播种时间,采用保护性耕作,抗旱品种培育与生物抗旱技术,大力修建蓄水工程,发展设施农业等措施改善水资源利用状况,提高旱作农业的可持续发展能力。更多还原

【Abstract】 Precipitation is the major water resource in dryland farming systems of hot and summer drought areas. To use agricultural water resources rationally, meliorate contradiction of water supply and demand, propose optimization scheme of adjusting agricultural water use, get the ultimate goal to efficiently use of precipitation, the study of precipitation supply-demand state, evaluation of water ecological adaptability in dryland farming systems are terribly necessary.In this study, with the basic objective to optimize species of crops and reuse precipitation, according to survey data and field test results, taking representatives of hot and summer drought areas, Fengjie, Wanzhou, Shapingba as study areas, water demand was calculated for several major crops as wheat, corn, sweet potato, potato, horsebean, soybean, rape and the main planting patterns as wheat-corn-sweet potato, horsebean-corn-sweet potato, wheat-corn-soybean, potato-corn-sweet potato, horsebean-corn-soybean, rape-corn-sweet potato, analysed systematically the temporal relationship between crop growth and rainfall distribution, water supply-demand equilibrium and dislocation characteristics of the main crops and planting patterns in farmland with the slope 0°,5°, 10°,15°,20°,25°, on different years of rainfall types, and evaluated by mathematical model of water ecological adaptability, in order to provide scientific guidance for optimizing planting system and improving production techniques. The main results were as follows:(1) Distribution characteristic of precipitation in time and space and effective rainfall:There was large change in Chongqing annual rainfall, and since 1994, this wave was being great. The average rainfall centralized mainly in four months period from May to September, accounting 68.62% of total annual rainfall, of which the maximum rainfall appeared in July. Three rainfall types year of Fengjie were mainly decided by actual rainfall in the months from May to September. Precipitation from May to September accounted 76.48% of the total rainfall in wet year, the percent in average year was 67.34%, and dry year was 64.39%. The month rainfall differences of three rainfall types year in Wanzhou was mainly centralized in the months from July to September, precipitation from July to September accounted 51.46% of the total rainfall in wet year, the percent in average year was 51.46%, and dry year was 50.49%. The most obvious rainfall difference of three rainfall type year in Shapingba appeared in July, in the wet year, the rainfall of July accounted 38.45% of the total rainfall, and just 9.97% in average year,3.25% in the dry year. In the same region and the same rainfall type, the effective rainfall was less and less as the slope increasing. Compared with 0°farmland, the effective rainfall in the farmland with slope of 5°,10°,15°,20°, 25°was decreased by 4%,12%,20%,27 and 35% respectively.(2) Crop water demand and crop coefficient in dry land: the order of average annual reference evapotranspiration of three study regions and Beibei was Fengjie>Beibei>Wanzhou>Shapingba. The monthly distribution of daily average reference evapotranspiration was similar with temperature distribution, of which higher values appeared in the months from May to August. The order of major single crops coefficient with whole growth period was sweet potato potato>soybean>horsebean >rape>maize>wheat. As the same crop or the same planting pattern, the order of water demand in different regions was Fengjie>Beibei>Wanzhou>Shapingba. As the same region, the order of different complex planting pattern water demand was: rape-corn-sweet potato >horsebean-corn-soybean>potato-corn-sweet potato>wheat-corn-soybean>horsebean-corn-sweet potato>wheat-corn-sweet potato.(3) Water supply-demand equilibrium characteristic of the main dryland crops and cropping patterns in hot and summer drought areas: In the same rainfall type year, water satisfaction rate of monoculture crops and complex cropping patterns in different study regions was less and less as the as the slope increasing. The growth period of complex planting pattern was the whole production year, in the same study region, the water satisfaction rate of complex planting patterns was related to rainfall type, and the order was wet year>average year>dry year. In the flat farmland, sweet potatoes, corn and soybeans were appropriate to plant in wet and average year, wheat and rape could be chosen in dry year as a few suitable crops in Fengjie. The monoculture crops suitable for Wanzhou in three rainfall types were more, such as corn, potatoes, horsebean and rape. The water satisfaction rate of monoculture crops in Shapingba were greater than or equal to 1, on which could choose the crop varieties according to actual needs. As Fengjie there was just wheat-corn-sweet potato, horsebean-corn-sweet potato and wheat-corn-soybean could be planted on smaller slope land in wet year. But for Wanzhou, all of the complex planting patterns were suitable in wet year, and wheat-corn-sweet potato could be chosen in average year. As Shapingba, wheat-corn-sweet potato, horsebean-corn-sweet potato and wheat-corn-soybean were suitable in average year.(4) The rule of water ecological adaptability of dryland farming systems in hot and summer drought areas: According to water ecological adaptability index size and stability of growth period in three study regions, the order was Shapingba>Wanzhou>Fengjie. The whole growth period was disparted into four parts asⅠ,Ⅱ,ⅢandⅣ. Then analysed the water ecological adaptability index of four growth periods separately. Monoculture crops with low water ecological adaptability index (less than 0.9) in Fengjie were wheat which ecological adaptability index in whole and II growth period was 0.85 and 0.84, potato which ecological adaptability index in whole growth period was 0.85, maize which ecological adaptability index in whole and III growth period was 0.89, horsebean which ecological adaptability index in whole,ⅡandⅢgrowth period was 0.79,0.8 and 0.73 respectively, rape which ecological adaptability index in whole andⅡgrowth period was 0.77 and 0.75. As the Wanzhou, wheat in II was 0.85, horsebean in the whole,ⅡandⅢwas 0.81,0.8 and 0.89 respectively, rape in II was 0.77. As Shapingba, horsebean in II was 0.89. The water ecological adaptability index order of complex planting patterns in three study regions was Shapingba>Wanzhou>Fengjie. Patterns with low water ecological adaptability index (less than 0.8) in Fengjie were potato-corn-sweet potato which was 0.78, rape-corn-sweet potato which was 0.73, and horsebean-corn-soybean which was 0.75.(5) Agricultural water-saving and drought-resistance countermeasures of dryland:As the characteristics of high frequency and long duration of summer hot and drought, uneven spatial and temporal distribution of rainfall in hot and summer drought areas, some measures should be taken to meliorate water resources utilization and improve dryland agricultural sustainable development ability, such as planting structure and planting time adjustment, using conservation tillage, cultivating drought-resistant varieties, taking biological drought-resistance technology, building water-storage project and developing building agriculture.更多还原