玉米冠层对喷灌水量再分配影响的田间试验研究

为了确定喷灌水量通过作物冠层时的分配规律，定量评价作物冠层对喷灌水利用率的影响，该文采用水量平衡法对喷灌条件下的玉米冠层上部、棵间、茎秆下流及冠层截留水量进行了田间观测。试验结果表明，喷灌水经玉米冠层再分配后所形成的棵间和茎秆下流水量分别占冠层上部水量的45.4%和43.0%。截留水量空间分布变化较冠层上部、棵间和茎秆下流水量为大，均值为3.6 mm，变异系数Cv平均值为0.5。由相关分析知茎秆下流水量和棵间水量均随冠层上部水量的增加而线性增加，但茎秆下流水量与冠层上部水量的关系更为密切。冠层上部水量、叶面积和株高对截留量的影响较小。

Sprinkler water distributions as affected by corn canopy

A developing canopy has great potential to modify the distributions of water applied through overhead sprinkler irrigation system. The amount of water applied above canopy, throughfall, stemflow, and interception storage were measured using a water balance method during the growing season of sweet corn in northern China plains to evaluate the incorporation of corn canopy in sprinkler water distribution. A high variability of canopy interception storage with a coefficient of variation(CV) of 0.5 was observed in the experiments. The averaged interception storage for all measurements was 3.6 mm. The averaged throughfall and stemflow accounted for 45.4% and 43.0% of water applied above canopy, respectively. It was also found that both throughfal and stemflow increased linearly with sprinkler water applied. Water above-canopy, leaf area and plant height have little influence on canopy interception.