【作者】 王伟；

【导师】 蔡焕杰；

【作者基本信息】 西北农林科技大学 ， 农业水土工程， 2009， 硕士

【摘要】 调亏灌溉是一种新的节水灌溉技术,它利用作物自身对水分胁迫的生理生化反应,达到提高经济产量、减少水分无效消耗、提高水分利用率的目的。在广大的干旱半干旱地区,调亏灌溉技术有着广阔的应用前景,该技术的应用,将带来巨大的经济效益和社会效益。本文选取我国北方广泛种植的大田作物冬小麦和夏玉米为试验材料,进行了调亏灌溉试验,分析研究了调亏灌溉对冬小麦和夏玉米的生长和产量的影响机制,得出了以下结论:(1)拔节期、抽穗期以及灌浆成熟期前期,冬小麦叶片叶绿素相对含量受调亏水平影响不大且表现出一定的补偿效应。灌浆成熟期后期,冬小麦叶片叶绿素相对含量的高低与总灌水量成正比,总灌水量大的处理叶绿素相对含量较高,反之则较低。苗期、拔节期和抽穗期任何一个生育期完全不灌水将使冬小麦在灌浆成熟期末叶片迅速枯黄,小麦早熟。(2)抽穗期为冬小麦需水的一个关键时期,这一时期的水分亏缺会导致冬小麦蒸腾速率和光合速率的降低,抑制冬小麦的生长。苗期高定额(75mm)灌水、拔节期和抽穗期低定额(45mm)灌水,该处理组合一定程度上抑制了蒸腾无效耗水,提高了水分利用率。另外,在苗期、拔节期和抽穗期的水分严重亏缺或者不灌水可降低冬小麦的气孔导度50%左右。(3)亩穗数、千粒重和产量大体上与全生育期内总灌水量成正比,拔节期和抽穗期的土壤水分对冬小麦千粒重和产量的影响最为显著。无论是苗期、拔节期和抽穗期任一生育期不灌水都将对亩穗数、千粒重和产量造成严重影响,其中抽穗期是冬小麦产量形成的最关键时期。苗期低定额(45mm)灌水、拔节期高定额(75mm)灌水,抽穗期和灌浆成熟期中定额(60mm)灌水的处理可达到节水高产的目的。(4)夏玉米从出苗到抽穗期末期株高逐日增加,抽穗期末期一直到夏玉米成熟,株高基本无变化。其中,拔节-抽穗期夏玉米株高增速最快,株高平均每天增加4.5cm左右,抽穗期以后增速放缓。在三叶-拔节期对夏玉米进行中定额灌水处理,后期复水,夏玉米株高能表现出明显的补偿效应,拔节-抽穗期为夏玉米对水分亏缺最为敏感的时期。夏玉米株高在抽穗期以前已经形成,抽穗期后再对其进行亏水处理已不能对其构成影响。(5)在灌浆期之前,夏玉米茎粗随时间增大;灌浆期以后,茎粗基本不再变化或略微减小。三叶-拔节期对夏玉米进行中定额灌水处理,在拔节-抽穗期复水后茎粗能表现出一定的补偿效应。夏玉米茎粗在抽穗-灌浆期前已经形成,这一时期及这一时期后的其它生育期的水分亏缺将对夏玉米的茎粗不再构成影响。(6)夏玉米冠部鲜重是一个先增高后降低再趋于稳定的过程;干重在整个生育期内是一个逐渐增加的过程。在三叶-拔节期对夏玉米进行中定额灌水处理,拔节-抽穗期复水,夏玉米冠部生长能表现出一定的补偿效应。拔节-抽穗期和抽穗-灌浆期是冠部生长对水分较为敏感的两个时期,其中拔节-抽穗期对水分亏缺的反应更为敏感。(7)三叶-拔节期对夏玉米进行中定额灌水处理,在拔节-抽穗期对其复水,后高定额供水,夏玉米无论在穗长、穗粒重、百粒重、产量还是水分利用效率(WUE)上都能表现出明显的优势,达到了节水高产的目的;抽穗-灌浆期对夏玉米进行水分亏缺处理,虽然在其他生育期适宜供水,也会严重降低夏玉米的产量和WUE等,这说明抽穗-灌浆期为夏玉米产量形成的最关键时期,这一时期的水分亏缺会严重影响夏玉米的产量。更多还原

【Abstract】 Crop Regulated Deficit Irrigation(RDI) is one of water saving irrigation technology which base on crop’s physiological and biochemical reflection to water deficit.RDI can increase crop yield, and decrease water consumption, and raise the WUE. RDI have great future in the arid and semiarid area. If RDI was widely used in China, it will biring great economic and social benefit.Winter wheat and summer corn are the material of RDI experiments in this dissertation. Through studying on growth and yield under regulated deficit irrigation about wheat and summer corn, there are some main results as follows:(1)In jointing heading and the pre-maturing, the relative leaf chlorophyll contents of winter wheat is slightly influenced by the level of RDI and there is a phenomenon of compensation about it. In later maturing, the level of the relative leaf chlorophyll contents of winter wheat is positive correlation with irrigation quantity. No irrigation in any of seeding jointing or heading will make winter wheat leaves scorch quickly in later maturing, the wheat ripens early.(2)Heading is the key stage of winter wheat requiring water, water deficit in this stage will result in evaportranspiration rate and photosynthesis rate depress, restrain the growth of winter wheat. Appropriate water in seeding severe water deficit in jointing and heading can restrain wast transpiration water improve water use efficiency(WUE). In addition, severe water deficit or no irrigation can decrease stomatal conductance seriously.(3) Spikes per mu 1 000-grain weight and yield are generally positive correlation with the total amount of irrigation, the soil water in jointing and heading is remarkably inflencing 1 000-grain weight and yield of winter wheat, among them, heading is the most important stage to form yield. Sever water deficit in seeding appropriate water in jointing slight water deficit in heading and maturing can achieve the purpose of Water-saving and High-yield.(4)From seeding to later heading the plant height of summer corn increasing everyday, later heading till maturing, the plant height of summer corn does not change on the whole. In jointing-heading the plant height of summer corn increases fastest, about 4.5cm one day, the speed becomes slow in later heading. Slight water deficit in trefoil-jointing, later appropriate water, the plant height can show a obvious phenomenon of compensation, jointing-heading is the most sensitive stage of summer corn to soil water. The plant height of summer corn forms before heading, water deficit is not effect to plant height in later heading.(5)Before filling, the diameter of summer corn is increasing everyday; from later filling, the diameter of summer corn is not changes or diminishes slightly. Slight water deficit in trefoil-jointing, appropriate water in jointing-heading, the diameter of summer corn can show a certain degree of compensation. The diameter of summer corn formes before heading-filling, water deficit in this and later stage is not effect to it.(6)The crownlike fresh mater of summer corn is a process which raise in the beginning and reduce in the latering while the crownlike dry mater is a process increasing constan. Slight water deficit in trefoil-jointing, appropriate water in jointing-heading, the crownlike dry mater can show a certain degree of compensation. Jointing-heading and heading-filling are both sensitive stages of summer corn to soil water, and jointing-heading is more sensitive than heading-filling.(7)Slight water deficit in trefoil-jointing, appropriate water in the later stages, summer corn becomes more advantage in ear length weight of spike 100-grain weight yield and also WUE, achieve the purpose of Water-saving and High-yield; water deficit in heading-filling, even appropriate water in every other stages, can decrease yield WUE and so on of summer corn also, this indicates that heading-filling is the most important stage for summer corn to formes yield, and water deficit in this stage can decrease it severly.更多还原