【作者】 薛亮；

【导师】 王林权；

【作者基本信息】 西北农林科技大学 ， 植物营养学， 2008， 硕士

【摘要】 水分和氮素与作物生长有密切关联,农业水肥资源短缺与不合理的使用造成水肥利用率低并导致资源浪费和环境污染。交替灌溉施肥是一项新的节水施肥技术,其对作物根系生长及养分吸收、作物地上部分生长发育和水分生理状况、光合作用与作物产量,以及水分利用效率等方面的研究已取得较大进展。但对在交替灌溉施肥条件下水肥资源精确配置的研究尚未见报道。因此,研究交替灌溉施肥条件下水肥耦合效应,及其作物生理生化代谢变化,水分、养分在土壤中的分布规律,及其吸收利用效率等,有利于进一步丰富和完善这一新的节水灌溉技术理论体系,更有效地指导农业生产实践。本试验以夏玉米为供试作物,通过连续两年大田试验研究了交替灌溉施肥条件下的水氮耦合效应及其生理生态效应。2006年试验分别设置三个水氮水平,研究了不同水氮配合的产量效应、光合特性、植株水势以及氮素在土壤中的残留等。2007年试验采用二次正交旋转组合设计(二因素五水平),就交替灌溉施肥对作物产量、水氮吸收与分配、水氮利用效应,以及水氮最佳配比等进行了系统研究。取得了以下主要结论和进展:1、在陕西关中地区小麦-玉米轮作条件下夏玉米田补充灌溉和施用氮肥均有增产效应,氮素作用大于水分作用;水、氮交互作用为正效应。在供试条件下,控制性交替灌溉施肥的最佳水氮配比范围为:生育期总灌水量699～887 m3/hm2,总施氮量194～224 kg/hm2;最高产量以及相应水氮最佳配比为:最高产量6936 kg/hm2,总灌水量为816 m3/hm2,总施氮量为209 kg/hm2。在水肥异区交替灌溉施肥条件下,产量高于常规施肥灌水(5974 kg/hm2),并且最高产量的水氮投入量远低于当地生产中的常规灌水量(1800 m3/hm2)和施肥水平(300 kg/hm2),说明分根交替灌溉施肥技术节水节肥效应显著,在当地玉米生产中具有良好的应用前景。2、夏玉米追肥和补充灌溉均对WUE生物量和WUE籽粒产量有促进作用,水、氮交互作用为正效应;氮素作用显著大于水分作用;本试验各处理最高WUE生物量达到2.61 kg/m3,WUE籽粒产量达到1.47 kg/m3。3、分根交替灌溉施肥能有效地提高夏玉米氮肥利用率和氮肥效率。施氮量为150 kg/hm2,灌水量为700m3/hm2时氮肥利用率比常规管理(CI)高1倍。交替灌溉施肥能够促进养分在籽粒中的分配,减少了后期氮素在其它器官中的滞留比例。与常规施肥灌水相比,交替灌溉施肥处理的氮肥效率增加2-3倍。4、本试验中生育期灌水量达到900m3/hm2,施氮量为225 kg/hm2时土壤剖面的水分和养分即可以进行合理的渗透和运移,无论在灌水区还是施肥区硝态氮在0～80cm的区域高于其它处理,有利于作物吸收,也减少了硝态氮的淋失。当灌水量超过1350 m3/hm2时肥料的淋溶损失严重;常规灌水施肥条件下(灌水1800 m3/hm2,施氮量300kg/hm2)水氮淋失严重,水肥交替异区施肥可以减少氮素淋失,但当灌水超过1350 m3/hm2时,交替灌溉施肥的效应减弱。5、交替灌溉施肥方式使得夏玉米生长后期叶片持绿时间长,延长了灌浆时间,有利于增加产量;灌水和施肥都能提高作物水势;中等水平的水氮投入量往往在光合速率、蒸腾速率、单叶水分利用率和叶绿素硝酸还原酶以及伤流液等方面具有潜在优势。更多还原

【Abstract】 Water and nitrogen are two kinds of factors for plant growth. The shortage of water and fertilizer resources and no-rational apply of N fertilizer often result in problems of resource pollution and environmental deterioration associated with low efficiency of water and fertilizer utilization. Researches has made further progress of alternating irrigation on plant root growth, physiology, grain yield and water utilization etc. However, few was reported about accurate the number of water and fertilizer application under alternating furrow irrigation and fertilizer placement. Just for this reason, we had made a 2 years field study with the aim to provide scientific and technical basis to save irrigation water and N fertilizer.The experiments were carried out on a field of the station of irrigation of key lab of agronomical water and soil engineering,ministry of education, and the key lab of water saving agriculture in dryland,ministry of agriculture, in Northwest A & F university, yangling, Shaanxi province, China in 2006-2007, and the tested crop was maize. We designed 3 different water and nitrogen levels to study the effects of water and N coupling on yield, physiology characteristics and the residual nitrogen in soil profiles etc in 2006. In 2007, we studied the effects of water and N coupling on the yields, growth of plant, water and N uptake, water use efficency and N use efficiency etc under alternating furrow irrigation and N placement systems(AFINP) with orthogonal rotatable central composite design. The main results as following:1. Both irrigation and nitrogen application could raise maize yield in cultivation systems of 2 harvests, wheat and corn, annualy. The effect of N fertilizer application is more significantly than that of water irrigation. There were positive interactions between water and N. The range of optimal input is:irrigation: 699～887m3/hm2 & N applications 194～224 kg/hm2.The optimal coupling of water irrigation and N are 816 m3/hm2 and 209 kg/hm2, respectively, and the highest yield is 6936 kg/hm2. Compared with the traditional irrigation model, the new irrigation model, alternating irrigation and N placement, had important theoretical and practical significance for reducing water resource and N application and increasing fertilization use efficiency.2. The experiment was conducted to study the effects of irrigation and nitrogen application rates on summer maize water use efficiency under alternating furrow irrigation and N fertilizer placement. The results showed that the effect of nitrogen fertilizer on WUE was greater than irrigation. From the factor effect, we found the top WUE base to biological yield and seed yield were: 2.61kg/m3 and 1.47kg/m3.3. Alternating furrow irrigation and fertilizer placement significantly increased NUE and NFE, but there was no significant difference among water levels, the same as N. The NUE of AFINP was surpassed that of CI by 2 times when N application was in middle level (150 kg/hm2) coordinated with suitable water level (350m3/hm2). It was efficacious for Nitrogen to transfer to seed from other organs under alternating furrow irrigation and fertilizer placement. The N fertilizer efficicency(NFE)of AFINP were higher that of traditional irrigation with 2-3 times.4. During the maize plant growth stage and after harvest, nitrate content were accumulated in 0～100cm soil profiles when the mount irrigation amount was small than 900 m3/hm2,and N application rate was small than 225 kg/hm2. It would be beneficial to be uptake by maize and the next crop,winter wheat, meanwhile,it is helpful to avoid the threaten of NO3--N leaching to ground water.5. The high level of chlorophyll could last longer time than other treatments under alternating furrow irrigation and fertilizer placement in the filling stage which was benefit to the grain yield. The middle level of water and N has a positive influence in plant physiology. When the irrigation rate was reduced, the Pn and Tr both decreased, but Tr descend more fast than Pn, so, the LWUE was increased. The test results showed that it has an advantageous effect on leaf water utilization efficiency when the irrigation was 900m3/hm2 and N application was 225kg/hm2.更多还原