摘要
温室作物叶-气系统水流阻力的确定对计算作物蒸腾量、制定温室作物灌溉制度以及调控温室小气候具有重要意义,但测量难度较大。该文通过对温室作物周围环境微气象条件的连续观测,计算分析了温室作物叶-气系统水流阻力各分项即叶片周围层流副层边界层阻力(rb)、冠层上方湍流边界层阻力(rg)、空气动力学阻力(re)和叶片气孔阻力(ri)的变化规律。结果表明:温室内rb比较稳定,平均约235s/m,且与环境因素关系不甚密切;温室内黄瓜、西红柿类植物生殖生长期rg<<rb,在计算re时,rg的影响可忽略,取re≈rb;利用基于能量平衡方程和空气动力学方程得出的叶-气温差计算公式计算得到ri,符合其变化的一般规律;在此基础上计算了温室黄瓜的蒸腾速率,与实测值的一致性较好。
The resistance for vapor transfer in leaf-air system is important for estimating the transpiration of crops in the greenhouse by Penman-Monteith Model and managing the microclimate and determination of the irrigation schedule. The method and its principle of measuring the laminar boundary layer resistance(r_b) in the greenhouse was introduced in this paper. The measured result showed that the average of r_b was about 235 s/m and did not change with greenhouse environment. Estimating the turbulent boundary layer resistance(r_g) at different heights under different wind speeds, it is found out that r_g was much smaller than r_b during the reproductive development period of tomato and cucumber in the greenhouse, so we assumed r_e≈r_b (r_e is the external resistance). The stomata diffusive resistance(r_i) of any time scope was calculated by the model of T_l-T_a formulated based on energy and mass balance equation, simultaneously by continuously monitoring the greenhouse environmental factors. There was a good relationship between the daily transpiration of greenhouse cucumber crops measured and predicted by Penman-Monteith model. This is a useful method to get the resistance for vapor transfer in leaf-air system of crops in the greenhouse for its convenience, less-interference and succession.
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2004年第6期46-50,共5页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金(30170538)
国家科技部"863"项目(2001AA247042)资助
关键词
温室
层流边界层阻力
叶片气孔阻力
蒸腾速率
greenhouse
laminar boundary layer resistance
stomata diffusive resistance
transpiration
