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1.
根区湿润方式对玉米根系生长发育的影响   总被引:6,自引:0,他引:6  
将厚塑料紧密地固定在盆栽试验用桶壁和底的中央,玉米种子播种于厚塑料布的正上方,在均匀灌水、固定部分根区灌水和根系分区交替灌水3种方式下,分期测定两个1/2根区根系的长度、面积、干重以及单位面积的平均根长和比根长,研究不同根区根系的生长发育特征。结果表明,处理40d时,与其他根区相比,固定灌水非灌水区的比根长和单位面积平均根长明显增大,说明土壤水分减少使根系直径变小。根面积、长度以及干重的增长速率均表现为,处理0~5d内,与均匀灌水及其非灌水区相比,两种局部灌水的灌水区均显著增大;处理10~15d内,交替灌水的灌水区较其他根区明显增大,固定灌水的灌水区与均匀灌水相近。固定灌水时,灌水区根系的面积、长度、干重及其增长速率较之非灌水区显著增大;交替灌水时,两个根区的增长速率呈交替变化,其绝对数值随时间延长趋于相同。表明交替灌水不仅可刺激供水区根系的补偿生长,而且对恢复供水区也有补偿效应,并能够促使不同根区的根系均衡发展。  相似文献   

2.
不同灌溉方式下(土娄)土玉米根际硝态氮的分布   总被引:1,自引:0,他引:1  
实验着重研究分根条件下常规灌溉、交替灌溉和固定灌溉玉米苗期根际硝态氮的分布, 研究结果表明:不同灌水方式下,玉米根际硝态氮的分布不同.在这3种灌水方式的湿润区,NO-3-N的累积趋势为:交替灌水>固定灌水>常规灌水.  相似文献   

3.
实验着重研究分根条件下常规灌溉、交替灌溉和固定灌溉玉米苗期根际硝态氮的分布, 研究结果表明不同灌水方式下,玉米根际硝态氮的分布不同.在这3种灌水方式的湿润区,NO-3-N的累积趋势为交替灌水>固定灌水>常规灌水.  相似文献   

4.
采用固定滴灌(根区一侧固定供水)、控制性分根区交替滴灌(根区两侧交替供水)和常规滴灌(紧贴幼树基部供水)3种灌水方式和3种灌水定额(固定滴灌和交替滴灌均为10、20和30 mm,常规滴灌为20、30和40 mm),对比研究了控制性分根区交替滴灌对苹果幼树形态特征与根系水分传导的影响.结果表明: 交替滴灌的根区两侧土壤出现反复干湿交替过程,常规滴灌的根区两侧土壤含水率差异不显著.在灌水定额相同时,灌水侧的土壤含水率在3种灌水方式间差异不显著.与常规滴灌和固定滴灌相比,交替滴灌显著增加了苹果幼树的根冠比、壮苗指数和根系水分传导,在30 mm灌水定额处理下,交替滴灌的根冠比分别增加31.6%和47.1%,壮苗指数增加34.2%和53.6%,根系水分传导增加9.0%和11.0%.3种灌水方式下,根干质量和叶面积均与根系水分传导呈显著线性正相关.控制性分根区交替滴灌增强了苹果幼树根系水分传导的补偿效应,促进了根系对水分的吸收利用,有利于干物质向各个器官均衡分配,显著提高了根冠比和壮苗指数.  相似文献   

5.
根区不同灌溉方式对苹果幼苗水流阻力的影响   总被引:4,自引:0,他引:4  
研究了滴灌条件下根区不同灌溉方式(交替滴灌ADI、固定滴灌FDI和常规滴灌CDI)和灌水量对苹果幼苗及各组成部分水流阻力、气孔导度和叶面积的影响.结果表明:根区灌溉方式和灌水量对苹果幼苗水流阻力(R)的影响显著; 在相同的根区灌溉方式下,苹果幼苗根系阻力(Rr)随着灌水量的减少而增大,冠层阻力(Rs)随着灌水量的减少而减小.在相同灌水量下,与常规滴灌相比,交替滴灌和固定滴灌均提高了苹果幼苗叶片和叶柄阻力(Rl+p),降低了幼苗全株阻力(Rt)、Rr、Rs以及侧枝和主杆阻力(Rlb+mr).在20 mm和30 mm灌水定额下,交替滴灌的Rl+p分别比常规滴灌高1.06%和0.63%.在平均节水达33%的前提下,交替滴灌和固定滴灌的平均Rl+p分别比常规滴灌高19.65%和24.34%,但交替滴灌和固定滴灌的平均Rlb+mr分别降低了4.83%和14.97%.交替滴灌和固定滴灌等局部根区不同灌溉方式通过有效减小苹果气孔导度和叶面积,提高了Rl+p,从而减少了叶片的蒸腾失水,提高了苹果幼苗的水分利用效率,通过降低Rr和Rlb+mr提高了苹果幼苗调控水分的能力和抗干旱能力.  相似文献   

6.
苗期水分亏缺对玉米根系发育及解剖结构的影响   总被引:8,自引:2,他引:6  
Ma XF  Yu T  Wang LH  Shi X  Zheng LX  Wang MX  Yao YQ  Cai HJ 《应用生态学报》2010,21(7):1731-1736
利用盆栽试验,研究了不同水分亏缺[土壤含水量分别为田间持水量的75%~85%(对照)、65%~75%(轻度)、55%~65%(中度)、45%~55%(重度)]对玉米苗期根系发育及解剖结构的影响.结果表明:干旱抑制了植株生长,随着水分亏缺程度的加重,根系长度缩短、根直径变细、总生物量降低;而根系活力、根冠比、根尖多糖含量均增加;侧根根毛长度、根毛密度、根毛总长度在中度水分亏缺条件下达到最大.组织切片观察结果表明,根直径变细主要是由于根的中柱面积减小、导管直径缩小所致,不同水分亏缺处理间导管的数量差异不大,但水分亏缺使导管壁变得不规整.根尖多糖含量的增加主要表现在表皮细胞和根冠细胞内,在表皮细胞内多糖主要以游离形式分布,在根冠细胞内主要以淀粉粒形式分布.总之,在水分亏缺条件下,玉米通过改变导管结构、增加表皮细胞与根冠细胞内多糖的含量及扩大根毛总表面积,来调节根系对水分的吸收能力,增强玉米植株的抗旱性,但根毛并不随着亏缺程度的加重而无限制的增长,在过度干旱条件下,根毛会受到抑制或损伤.  相似文献   

7.
采用固定滴灌(根区一侧固定供水)、控制性分根区交替滴灌(根区两侧交替供水)和常规滴灌(紧贴幼树基部供水)3种灌水方式和3种灌水定额(固定滴灌和交替滴灌均为10、20和30 mm,常规滴灌为20、30和40 mm),对比研究了控制性分根区交替滴灌对苹果幼树形态特征与根系水分传导的影响.结果表明:交替滴灌的根区两侧土壤出现反复干湿交替过程,常规滴灌的根区两侧土壤含水率差异不显著.在灌水定额相同时,灌水侧的土壤含水率在3种灌水方式间差异不显著.与常规滴灌和固定滴灌相比,交替滴灌显著增加了苹果幼树的根冠比、壮苗指数和根系水分传导,在30 mm灌水定额处理下,交替滴灌的根冠比分别增加31.6%和47.1%,壮苗指数增加34.2%和53.6%,根系水分传导增加9.0%和11.0%.3种灌水方式下,根干质量和叶面积均与根系水分传导呈显著线性正相关.控制性分根区交替滴灌增强了苹果幼树根系水分传导的补偿效应,促进了根系对水分的吸收利用,有利于干物质向各个器官均衡分配,显著提高了根冠比和壮苗指数.  相似文献   

8.
水肥异区交替灌溉对夏玉米生理指标的影响   总被引:4,自引:0,他引:4  
以夏玉米品种‘户单4号'为材料,通过防雨棚内微区试验研究了两种灌水量(450 m~3/hm~2和900 m~3/hm~2)条件下水肥异区交替灌溉和均匀灌溉对夏玉米生长以及某些生理指标的影响.结果显示:(1)在节水50%的条件下,水肥异区交替灌溉与高灌水量均匀灌溉的夏玉米生物量、产量均无显著差异.(2)低灌水量时,水肥异区交替灌溉下的玉米根系伤流液、叶片可溶性蛋白含量、硝酸还原酶活性、光合速率、蒸腾速率等均高于均匀灌溉施肥处理,而植株全氮含量及叶片水分利用效率与均匀灌溉施肥的差异不显著.(3)高灌水量时,水肥异区交替灌溉处理除根系活力、光合速率以及蒸腾速率高于均匀灌溉处理外,其他指标均低于后者.研究表明,在低灌水量条件下,水肥异区交替灌溉能使夏玉米保持较高的根系活力和正常生理代谢,提高其叶片水分利用效率,从而达到了节水增产的目的.  相似文献   

9.
为了阐明根区交替控制灌溉(CRDAI)条件下玉米根系吸水规律,通过田间试验,在沟灌垄植模式下采用根区交替控制灌溉研究玉米根区不同点位(沟位、坡位和垄位)的根长密度(RLD)及根系吸水动态。研究表明,根区土壤水分的干湿交替引起玉米RLD的空间动态变化,在垄位两侧不对称分布,并存在层间差异;土壤水分和RLD是根区交替控制灌溉下根系吸水速率的主要限制因素。在同一土层,根系吸水贡献率以垄位最大,沟位最低;玉米营养生长阶段,10—30 cm土层的根系吸水速率最大;玉米生殖生长阶段,20—70 cm为根系吸水速率最大的土层,根系吸水贡献率为43.21%—55.48%。研究阐明了交替控制灌溉下根系吸水与土壤水分、RLD间相互作用的动态规律,对控制灌溉下水分调控机理研究具有理论意义。  相似文献   

10.
刘水  李伏生 《生态学报》2014,34(18):5249-5256
由于作物需水随生育期的变化,分根区交替灌溉(AI)的节水效果也会随生育期而发生变化,探明不同生育期分根区交替灌溉对玉米生长和水分养分利用的影响,以期为分根区交替灌溉的实施和充分发挥其节水节肥效果奠定理论基础。通过盆栽试验,在2种灌水水平(正常灌水和轻度缺水)和2种有机无机氮比例(100%无机氮和70%无机氮+30%有机氮)下,以常规灌溉(CI)为对照,分别研究苗期—灌浆初期、苗期—拔节期以及拔节期—抽雄期进行AI对玉米干物质量、氮钾含量和吸收量以及土壤碱解氮和速效钾含量的影响。结果表明,在轻度缺水和有机无机氮肥配施下,与CI相比,拔节期—抽雄期分根区交替灌溉玉米地上部和总干物质量分别增加29.6%和27.4%,地上部和总N吸收量增加50.7%和50.4%。与单施无机氮肥相比,有机无机氮肥配施会在不同程度上增加地上部和总N吸收量,但是一般降低土壤碱解氮和速效钾含量,这说明在轻度缺水和有机无机N肥配施下,拔节期—抽雄期进行分根区交替灌溉提高玉米总干物质量和N吸收量。  相似文献   

11.
Effects of partial root-zone irrigation (PRI) on the hydraulic conductivity in the soil-root system (L(sr)) in different root zones were investigated using a pot experiment. Maize plants were raised in split-root containers and irrigated on both halves of the container (conventional irrigation, CI), on one side only (fixed PRI, FPRI), or alternately on one of two sides (alternate PRI, APRI). Results show that crop water consumption was significantly correlated with L(sr) in both the whole and irrigated root zones for all three irrigation methods but not with L(sr) in the non-irrigated root zone of FPRI. The total L(sr) in the irrigated root zone of two PRIs was increased by 49.0-92.0% compared with that in a half root zone of CI, suggesting that PRI has a significant compensatory effect of root water uptake. For CI, the contribution of L(sr) in a half root zone to L(sr) in the whole root zone was ~50%. For FPRI, the L(sr) in the irrigated root zone was close to that of the whole root zone. As for APRI, the L(sr) in the irrigated root zone was greater than that of the non-irrigated root zone. In comparison, the L(sr) in the non-irrigated root zone of APRI was much higher than that in the dried zone of FPRI. The L(sr) in both the whole and irrigated root zones was linearly correlated with soil moisture in the irrigated root zone for all three irrigation methods. For the two PRI treatments, total water uptake by plants was largely determined by the soil water in the irrigated root zone. Nevertheless, the non-irrigated root zone under APRI also contributed to part of the total crop water uptake, but the continuously non-irrigated root zone under FPRI gradually ceased to contribute to crop water uptake, suggesting that it is the APRI that can make use of all the root system for water uptake, resulting in higher water use efficiency.  相似文献   

12.
Partial root-zone irrigation creates a dynamic heterogeneous distribution of soil moisture that may affect the numbers and activities of soil microorganisms. In this study, three irrigation methods, i.e. conventional irrigation (CI), alternate partial root-zone irrigation (APRI, alternate watering on both sides of the pot) and fixed partial root-zone irrigation (FPRI, fixed watering on one side of the pot), and three watering levels, i.e. well-watered, mild and severe water deficit, were applied on pot-grown maize. Numbers of soil microorganisms, plant height, stalk diameter, leaf area and biomass accumulation were monitored over the treatment period. A quadratic parabola relationship between the number of soil microorganisms and soil water content was found, indicating the number of soil microorganisms reached a peak at the mild soil water deficit condition, possibly due to better soil aeration. The peak number of soil microorganism was obtained when soil water content was 66, 79 and 75% of field capacity for CI, FPRI and APRI, respectively. Soil microorganisms were evenly distributed in both sides of APRI and their total numbers were always higher than those under other two irrigation methods for the same soil water content. The count of soil microorganisms in the dry root zone of FPRI was reduced by a lack of water. Maximum biomass accumulation was obtained under well watered condition but severe water deficit led to a 50% reduction in the CI treatment. Such reduction was much smaller under APRI and therefore the highest water use efficiency was obtained. Our results suggest that APRI maintained the best aeration and moisture condition in the soil and enhanced the activities of soil microorganisms, which might also have benefited the plant growth.  相似文献   

13.
Alternate partial root-zone irrigation (APRI) is a new water-saving technique and may improve crop water use efficiency without much yield reduction. We investigated if the benefits of APRI on biomass accumulation, water and nitrogen use efficiencies could be modified by different soil fertilization and watering levels in pot-grown maize (Zea mays L. cv. super-sweet No 28, a local variety). Three irrigation methods, i.e. conventional irrigation (CI), alternate partial root-zone irrigation (APRI, alternate watering on both sides of the pot) and fixed partial root-zone irrigation (FPRI, fixed watering on one side of the pot), two watering levels, i.e. water deficit (W1, 45–55% of field capacity) and well-watered (W2, 70–80% of field capacity), and two N fertilization levels, i.e. no fertilization and fertilization, were designed. Results showed that APRI and FPRI methods led to more reduction in transpiration than in photosynthesis, and thus increased leaf water use efficiency (leaf WUE, i.e. the ratio of leaf net photosynthetic rate to transpiration rate). Compared to the CI treatment, APRI and FPRI increased leaf WUE by 7.7% and 8.1% before the jointing stage and 3.6% and 4.2% during the jointing stage, respectively. Under the fertilization and well-watered conditions, APRI treatment saved irrigation water by 38.4% and reduced shoot and total dry masses by 5.9% and 6.7%, respectively if compared to the CI treatment. APRI also enhanced canopy WUE (defined as the amount of total biomass per unit water used) and nitrogen (N) apparent recovery fraction (Nr, defined as the ratio of the increased N uptake to N applied) by 24.3% and 16.4%, respectively, indicating that effect of APRI can be better materialized under appropriate fertilization and water supply. Responsible Editor: Rana E. Munns  相似文献   

14.
根系分区交替灌溉不同交替周期对苹果树   总被引:6,自引:0,他引:6  
刘贤赵  宿庆  孙海燕 《生态学报》2010,30(18):4881-4888
以11~12年生苹果树为研究对象,于2006~2007年在烟台市农科院果树研究所试验果园进行了根系分区交替灌溉(APRI)试验,研究了APRI灌溉模式下不同交替灌溉周期对苹果树生长、产量、品质及水分利用效率的影响。结果表明,APRI处理的苹果树湿润一侧土壤含水量随深度增加而减少,并出现明显拐点,交替周期愈短拐点愈接近地表,干旱一侧则随深度增加而增大,二者含水量最大差值出现在土壤表层0~10 cm。每2周交替灌溉1次的APRI1处理的叶水势、净光合速率、蒸腾速率和气孔导度稍有降低,但与对照均没有明显差异,而每4周交替灌溉1次的APRI2和APRI3处理的上述指标则显著低于对照(P < 0.05)。APRI处理显著抑制植株的新梢生长,但对果实直径没有显著影响。APRI1和APRI2处理的苹果产量比对照和APRI3下降了11.1 %~14.8 %,但供水量减少了50 %,水分利用效率提高了71 %~80 %,而且显著提高了可溶性固形物含量和果实干物质含量,使果实含酸量降低,果实硬度增加,果实品质明显改善。由此可以推断采用根系分区交替灌溉并进行适宜的交替周期处理(如本试验中的APRI1)可以达到大量节水、提高苹果品质而不明显降低产量的目的,是苹果生产中一种切实可行的灌溉方式,值得旱地苹果园大力推广。  相似文献   

15.
基于节水灌溉技术原理与作物感知缺水的根源信号理论而提出的根系分区交替灌溉,是交替对作物部分根区进行正常的灌溉,其余根区受到适度水分胁迫的灌溉方式。应用同位素示踪技术追溯分根区交替供水条件下土壤-作物系统水分运转途径并揭示其节水调质机理是一个重要的研究方向。本文对根系分区交替灌溉的节水调质效应、节水机理、稳定性氢氧同位素在植物水分运移中的应用以及稳定性碳同位素在植物水分利用效率中的应用研究进展及应用前景作了简要介绍,并对将来需要重点研究的方向作了展望。以期为充分挖掘作物生理节水潜力,大幅度提高作物水分利用效率和实现节水、丰产、优质、高效的综合目标提供有效的调控途径。  相似文献   

16.
In maize ( Zea mays L. cv. LG 11) roots cultured in humid air, the presence of hairs was not related to root growth. However, maximum hair length and length of the hair zone could be correlated to the elongation rate of the primary root. Under the growth conditions used, the emergence of root hairs always took place in the extending zone. In more basal regions, rhizodermal cells could not give rise to root hairs. Results were similar for roots preincubated in a buffer solution.  相似文献   

17.
This paper reports a new barley mutant missing root hairs. The mutant was spontaneously discovered among the population of wild type (Pallas, a spring barley cultivar), producing normal, 0.8 mm long root hairs. We have called the mutant bald root barley (brb). Root anatomical studies confirmed the lack of root hairs on mutant roots. Amplified Fragment Length Polymorphism (AFLP) analyses of the genomes of the mutant and Pallas supported that the brb mutant has its genetic background in Pallas. The segregation ratio of selfed F2 plants, resulting from mutant and Pallas outcross, was 1:3 (–root hairs:+root hairs), suggesting a monogenic recessive mode of inheritance.In rhizosphere studies, Pallas absorbed nearly two times more phosphorus (P) than the mutant. Most of available inorganic P in the root hair zone (0.8 mm) of Pallas was depleted, as indicated by the uniform P depletion profile near its roots. The acid phosphatase (Apase) activity near the roots of Pallas was higher and Pallas mobilised more organic P in the rhizosphere than the mutant. The higher Apase activity near Pallas roots also suggests a link between root hair formation and rhizosphere Apase activity. Hence, root hairs are important for increasing plant P uptake of inorganic as well as mobilisation of organic P in soils.Laboratory, pot and field studies showed that barley cultivars with longer root hairs (1.10 mm), extracted more P from rhizosphere soil, absorbed more P in low-P field (Olsen P=14 mg P kg–1 soil), and produced more shoot biomass than shorter root hair cultivars (0.63 mm). Especially in low-P soil, the differences in root hair length and P uptake among the cultivars were significantly larger. Based on the results, the perspectives of genetic analysis of root hairs and their importance in P uptake and field performance of cereals are discussed.  相似文献   

18.
隔沟交替灌溉条件下玉米根系形态性状及结构分布   总被引:9,自引:0,他引:9  
为揭示根系对土壤环境的适应机制,研究了隔沟交替灌溉条件下玉米根系形态性状及结构分布。以垄位和坡位的玉米根系为研究对象,利用Minirhizotrons法研究了根系(活/死根)的长度、直径、体积、表面积、根尖数和径级变化及其与土壤水分、土温和水分利用效率(WUE)的相关关系。结果表明,对于活根,在坡位非灌水区域复水后根系平均直径减小,而根系日均生长速率、单位面积土壤根系体积密度、根尖数和表面积均增大,并随灌水区域土壤水分的消退逐渐减小;对于死根,在坡位非灌水区域复水后根系日均死亡速率、根系体积密度、根尖数和表面积变化均减小,其中根系死亡速率和死根直径随土壤水分的消退逐渐降低,而死根体积密度、根尖数和表面积分布随土壤水分降低呈增大趋势;在垄位,根系形态分布趋势与坡位一致,除根系直径与与坡位比较接近外,其他根系形态值均小于坡位。将根系分成4个径级区间分析根系的形态特征,结果表明在根系长度和体积密度分布中以2.5-4.5 mm径级的根系所占比例最大,在根尖数和根系表面积分布中以0.0-2.5 mm径级的根系为主。通过显著性相关分析,死根直径、体积密度、活根表面积等根系形态与土壤含水率、土壤温度和WUE间均存在显著或极显著的正相关关系,部分根系形态指标(如根系的生长速率、活根体积密度)只与坡位土壤含水量、土壤温度具有明显的相关性,表明隔沟交替灌溉对坡位根系形态的调控作用比垄位显著。  相似文献   

19.
水磷耦合对小麦次生根特殊根毛形态与结构的影响   总被引:1,自引:0,他引:1  
张均  贺德先  段增强 《生态学报》2011,31(11):3110-3119
通过水、磷复因子大田试验,以强筋小麦品种郑麦9023为材料,研究了水磷耦合对小麦生育中、后期次生根特殊根毛形态与结构的影响。结果指出,不同水分处理显著影响特殊根毛形态。随着土壤水分含量提高,次生根特殊根毛长度缩短。与土壤湿润处理相比,仅依靠自然降水处理的特殊根毛长度和直径增加(P<0.01),拔节至子粒形成期间完全灌溉处理的根毛长度增加(P<0.01)。随着供磷水平提高,特殊根毛长度和直径增加(P<0.05),其中高磷处理和对照(不施磷)的差异达极显著水平(P<0.01)。同一供水条件下随供磷水平提高,或同一供磷水平上随土壤含水量降低,特殊根毛长度和直径均增加(P<0.05)。拔节以后,仅依靠自然降水—高磷处理组合的特殊根毛细胞饱满,结构完整,细胞壁加厚明显,细胞核、液泡及线粒体清晰可见;而土壤湿润—低磷处理组合的特殊根毛扭曲、变形现象严重,细胞壁变薄,细胞核解体,质膜、微体等细胞器消失。研究表明,适当降低土壤含水量并提高供磷水平,小麦次生根特殊根毛的长度和直径增加,并维持良好的细胞形态和结构。  相似文献   

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