连续干旱条件下喷播基质水分衰退规律  

Water loss in growth media with continuous drought

作　　者：张小庆[1] 张金池[1] 王丽[1] 梦莉[1] 黄进[1] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037

出　　处：《浙江林学院学报》2010年第6期839-844,共6页Journal of Zhejiang Forestry College

基　　金：国家林业局引进国际先进农业科学技术计划(948计划)资助项目(2008-4-40);江苏省社会发展项目(BS200763)

摘　　要：喷播基质水分衰退规律直接影响喷播种子的发芽和幼苗生长。在大棚盆栽条件下,利用TDR(time-domain reflectome-ter)土壤水分监测系统对基质含水量测量发现:白三叶Trifolium repens,紫穗槐Amorpha fruticosa,波斯菊Cosmos bip-innatus和黑麦草Lolium perenne播种后分别于44,45,44和43d基质蒸发基本停止,失水量接近0,幼苗枯死率达到90%以上;基质含水量在12:00-13:00时下降速度最快,13:00-15:00时下降也较为明显,夜间冷凝现象不明显,将温度、相对湿度、时间和基质含水量拟合成多元回归方程,拟合效果较好;0～5cm基质层含水量一直低于5～10cm和10～15cm基质层,10～15cm基质层前期和后期失水速率较慢,中期失水速率较快,3个层次含水量最后趋于一致。With spray sowing,water loss in the growth medium directly affects seed germination and seedling growth.Using time-domain reflectometry（TDR）,the volumetric water content（VWC） of the growth medium which composed of the same materials in a greenhouse pot culture was measured.Four plant species were cultured with three repeats for each species.Regression equations were established for the progress of water loss to show the regulation and key drought time points of the water loss in growth medium.After seeding with Trifolium repens and Cosmos bipinnatus （44 d）,Amorpha fruticosa （45 d）,and Lolium perenne （43 d）,evaporation was near 0 with 90% of the seedlings having withered.Water content in the growth medium decreased the most between 12：00-13：00 followed by a strong decrease from 13：00 15：00.Also,water condensation was minimal at night.Regression equations composed of temperature,humidity,time,and VWC showed highly significant correlation （R20.92）.Water content in the 0-5 cm layer was always lower than the 5-10 and 10-15 cm layers.In addition,the rate of water loss in layer 10-15 cm was slow in earlier and later stages,but fast in the middle stage.After about 19 d,water content of the three layers was about the same.

关 键 词：土壤学 基质 水分衰退 含水量 

分 类 号：S714.7[农业科学—林学]