常用六种草坪草蒸散量及作物系数的研究

根据水分平衡法采用小型蒸渗仪测定了两种水分条件下 6种草坪草的蒸散量 ,并采用Penman Monteith经验公式计算确定了各草种的作物系数 .两种水分条件为充足供水和限量供水 .参试的草种为草地早熟禾 (PoapratensisL .Nuglade)、高羊茅 (FestucaarundinaceaSchreb .Hundog 5 )、多年生黑麦草 (LoliumperenneL .Advent)、普通狗牙根(Cynodondactylon(L .)Pers.)、野牛草 (Buchloedactyloides(Nutt.)Engelm .)、日本结缕草 (ZoysiajaponicaSteud .) .草种间 ,水分处理间的草坪蒸散量均表现较大差异 .充足供水的草坪的蒸散量比限量供水的蒸散量大 30 5～ 1 5 3 5mm .全生长季冷季型草坪草的蒸散量大于暖季型草坪草 ,最多相差 2 0 0mm .两种水分条件下 ,6种草坪草的生长季总蒸散量排序相同 ,最大蒸散量排序为高羊茅 (90 3 5 5mm) >草地早熟禾 (85 7 93mm) >多年生黑麦草 (85 0 91mm) >狗牙根 (82 5 6 1mm) >野牛草 (75 8 6 6mm) >日本结缕草 (70 1 5 5mm) .不同的水分处理 ,草种和季节对草坪的作物系数均有一定程度的影响 .冷季型草的生长季平均作物系数介于 0 98～ 1 0 9之间 ,暖季型草的介于 0 70～ 0 96之间 .充足供水条件下高羊茅和草地早熟禾的作物系数与限量供水条件下的作物系数差异不显著 ,多

Evapotranspiration rates and crop coefficients of turfgrasses in North China

The ET rates of six turfgrass species grown in the north of China are measured with mini lysimeter according to the water balance principles under two water conditions: non limited and limited water condition. And the crop coefficients of them are determined by the Penman Monteith formula. The six turfgrass species are kentucky bluegrass (%Poa pratensis% L. Nuglade),tall fescue ( Festuca arundinacea Schreb. Hundog 5),perennial ryegrass ( Lolium perenne L. Advent),bermudagrass ( Cynodon dactylon (L.) Pers.), buffalograss ( Buchloe dactyloides (Nutt.) Engelm.),and zoysiagrass ( Zoysia japonica Steud.).Research results indicate that there are significant differences among the ET rates of six turfgrass species, also between the ET rates of the same turfgrass under two water conditions. The ET rates of six turfgrass under non limited water condition are larger than those under limited water condition; the difference ranges from 30 5 to 153 5 mm. ET rates of cool season turfgrasses in the whole growing season are larger than those of warm season turfgrasses, the biggest difference is 200 mm. The orders of total turfgrasses ET rates in the growing season from high to low under two water conditions are same. Under non|limited water condition, the order is tall fescue(903 55 mm)> kentucky bluegrass(857 93 mm)>perennial ryegrass(850 91 mm)>bermudagrass(825 61 mm)>buffalograss(758 66 mm)>zoysiagrass(701 55 mm).The crop coefficients of turfgrass are influenced by water condition, turfgrass species and growing season. Cool season turfgrass crop coefficients range from 0 98 to 1 09, and warm season turfgrasses crop coefficients from 0 70 to 0 96. The difference of crop coefficients between two water conditions is not significant for tall fescue and kentucky bluegrass. But the crop coefficients of perennial ryegrass, bermudagrass, buffalograss and zoysiagrass under non limited water condition are significantly higher than that under limited water condition.