高级检索+

重庆四面山不同作物农田土壤根系分布与水分入渗特征

Root distribution and water infiltration characteristics of agricultural soils with different crops in the Simian Mountain of Chongqing

  • 摘要: 研究重庆四面山地区根系分布对农田土壤水分入渗的影响, 对当地的农田植被管理具有重要意义。选取玉米地、茄子地和南瓜地3种典型农田, 通过野外双环入渗实验测定土壤的水分入渗量和入渗率, 并分层采集土壤中的植物根系, 计算植物根系特征指标, 采用灰色关联度分析土壤根系与水分入渗的关系。结果表明: 1)玉米地、茄子地和南瓜地的初始入渗速率分别为258、213和285 mm/h, 平均入渗速率分别为154.99、136.84和203.07 mm/h。南瓜地的水分入渗量和入渗率相对最大, 茄子地相对最小; 2)3种农田的根系主要为直径3 mm以下的细根, 粗根数量较少, 各径级根长密度、根质量密度和根孔数量的最大值均出现在0~20 cm土壤处, 深层土壤的根系含量较少; 3)土壤中的植物根系对水分入渗有着一定影响, 各根系特征指标与各土壤水分入渗指标的灰色关联值均大于0.6, 细根对入渗的影响大于粗根。根系与外部供水在土壤中的运动息息相关, 在农田管理中, 作物根系是不可忽略的影响因素。

     

    Abstract:
    Background Simian Mountain in Chongqing is an important ecological barrier and main water source of the Yangtze River, and it is also one of the sensitive ecological areas in China. Due to long-term over-cultivation and frequent human activities in recent years, the local ecological conditions are very fragile, which seriously affects the growth of vegetation and has a negative impact on agricultural development, thus the local ecological restoration is very important.Soil water infiltration, as an important factor affecting vegetation growth and groundwater circulation, is a key factor in local farmland vegetation management.Therefore, it is of great significance to study the influence of root distribution on farmland soil moisture infiltration in Simian Mountain of Chongqing to local farmland vegetation management.
    Methods Three typical farmlands, namely corn(Zea mays) field, eggplant (Solanum melongena)field and pumpkin (Cucurbita moschata)field, were selected to measure soil water infiltration amount and infiltration rate through double-ring infiltration experiments.After that, the root system was sampled by soil column method. The root length density and root weight density of root samples were calculated by Epson Perfection V370 digital scanner and root analysis software (Win-RHIZO 2008a). The relationship between soil root system and water infiltration was analyzed by grey correlation degree method.
    Results 1) The initial infiltration rates were 258, 213 and 285 mm/h in the maize, eggplant, and pumpkin fields respectively, and the average infiltration rates were 154.99, 136.84, and 203.07 mm/h. The infiltration volume and infiltration rate were relatively the highest in the pumpkin field and the lowest in the eggplant field. 2) The amount of water infiltration and infiltration rate of the three types of farmland were the highest in the pumpkin field and the lowest in the eggplant field. 2) The root systems of the three types of farmland were mainly fine roots less than 3 mm in diameter, with a low number of coarse roots. The maximum values of root length density, root weight density, and root pore number for each diameter class were all found at 0-20 cm of soil, with less root content in deeper soils. 3) Plant roots in the soil have a certain influence on water infiltration, and the grey correlation values between each root characteristic index and each soil water infiltration index are all greater than 0.6, and the influence of fine roots on infiltration is greater than that of coarse roots.
    Conclusions The root system is closely related to the movement of external water supplies through the soil and is an influential factor in on-farm management that cannot be ignored.

     

/

返回文章
返回