不同灌水频率下设施土壤盐分时空变化特征

Temporal and spatial variation characteristics of salt in greenhouse soils under different irrigation frequencies

通过室内土箱模拟试验,探讨了不同灌水频率(5,10,15 d·次^(-1))下,栽培辣椒的设施土壤的盐分时空动态变化特征。结果表明,在各灌水频率条件下,根据土壤EC值变化,均可分为3个阶段:快速降低阶段(第1次灌水后1—20 d)、缓慢降低阶段(第1次灌水后21—40 d)和稳定阶段(第1次灌水后41—62 d)。不同灌水频率下0—20 cm土层EC值,在快速降低阶段和稳定阶段表现为5 d·次^(-1)>10 d·次-1>15 d·次^(-1),而在缓慢降低阶段却表现为5 d·次^(-1)>15 d·次^(-1)>10 d·次^-1)。0—20 cm土层积盐量,在缓慢降低阶段和稳定阶段,均以10 d·次^(-1)灌水频率下最低,表明其对0—20 cm土层盐分的淋洗作用较强。

In the present study, temporal and spatial variation characteristics of salt in greenhouse soils were ex-plored under different irrigation frequencies （every 5, 10, 15 d） during pepper growth by simulated experiments of soil box in greenhouse. It was shown that the whole monitoring period could be classified into 3 phases based on the changes of soil electrical conductivity （EC）： rapid decrease phase （1 -20 d after first irrigation）, slow decrease phase （21-40 d after first irrigation） and stable phase （41-62 d after first irrigation）. In rapid decrease phase and stable phase, EC value in 0-20 cm soil layer decreased as every 5 d 〉 every 10 d 〉 every 15 d. In slow de-crease phase, EC value in 0-20 cm soil layer decreased as every 5 d 〉 every 15 d 〉 every 10 d. In both slow de-crease phase and stable phase, the smallest salt accumulation in 0-20 cm soil layer was found under the irrigation frequency of every 10 d, indicating a stronger salt-leaching effect of this irrigation frequency.