摘要
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)×10-1mm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)×10-1mm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。
Alternate furrow irrigation is a biological water-saving technique and extensively applied to agricultural production in the arid and semi-arid region.There are the irrigated and non-irrigated root-zones alternately under alternate furrow irrigation.Because crop roots firstly sensed the variation of soil water and had a process of adaptation,their morphology characteristics and structure distribution under alternate furrow irrigation were studied to reveal the adaptive mechanism of roots system in the soil environment.Taking the roots both at ridge and slope as the research object,the minirhizotrons was used to investigate the changes of root length（living roots/dead roots）,diameter,volume density,surface area,root tip number and diameter class as well as the correlations between each parameter of roots and soil moisture,soil temperature,water use efficiency（WUE）.In the period of 52-78 day after the sowing of maize,the experiment was not influenced by rainfall（total precipitation is 5 mm in two times） and this period was chosen for the analysis of root morphology characteristics and structure distribution.Results showed maize roots were mainly distributed at ridge at the early growing stage,and its root production rate was greater than that at slope.Meanwhile,root metabolism was rapid with the higher root mortality rate.Alternate furrow irrigation had greater effect on the morphology indexes of maize roots at slope than at ridge,and after the re-watering in the non-irrigated root-zone at slope,the average root diameter was decreased,while the daily average root production rate,the volume density per unit soil area,the root tip number and surface area of the living roots were increased,and these indexes were gradually reduced with the decrease of soil moisture in the irrigated root-zone.At ridge,the average root diameter of the living roots is similar to that at slope,and the change trend of daily average root production rate,the volume density per unit soil area,the root tip number and surface area of
出处
《生态学报》
CAS
CSCD
北大核心
2011年第14期3956-3963,共8页
Acta Ecologica Sinica
基金
"十一五"国家科技支撑计划(2007BAD88B02)
中国农业科学院科技经费项目(201015)
商丘野外生态台站开放基金项目
国家自然科学基金项目(51009139)
