江西红壤坡地柑橘园生态水文特征及水土保持效益

在江西省水土保持生态科技园对标准柑橘试验小区生态水文特征进行9年的定位观测,设置7个处理,研究柑橘园生态水文特征及水土保持效益.结果表明： 7个处理的平均减流率和减沙率分别为78.5%和77.2%,其中，林下百喜草(Paspalum natatu)带状覆盖、百喜草全园覆盖和水平梯田+梯壁植草减流率较高,分别为94.8%、94.3%和92.5%;柑橘清耕地减流率较低,为33.1%；林下套种黄豆和萝卜减流率居中,为66.0%和77.5%,且横坡耕作优于纵坡耕作.对2009-2010年发生的43场平均降雨量为20.07 mm的雨水柑橘林冠再分配格局进行观测,穿透降〖JP2〗雨量平均为9.15 mm,树干茎流量平均为4.72 mm,林冠截留量平均为620 mm,分别占林外降雨量的44.7%、25.7%和29.6%.随着林外降雨量的增大,林冠层的穿透雨量、茎流量呈递增趋势.当降雨量<10 mm时,树冠截留率与林外降雨之间呈显著的线性负相关；当降雨量>10 mm时,二者之间的相关性不明显.柑橘枯落物的持水率与浸水时间呈对数回归关系,最大持水率达326%.合理的林下植被配置对柑橘果园的水土保持具有重要作用.

Eco-hydrological characteristics and soil and water conservation effect of citrus plantation on slope red soil of Jiangxi Province, China

A 9-year observation was conducted at the experimental plots in the Citrus reticulata plantation in Jiangxi Provincial Eco-Technology Park to study the eco-hydrological characteristics and soil conservation benefits of the plantation on slope red soil. Seven treatments were designed and monitored over nine years. The average flow and the rate of sediment for the seven treatments were reduced by 78.5% and 77.2%, respectively. The reduction rates were the highest in treatments band coverage of Paspalum natatu, whole coverage of P. natatu, and level terrace with grass on ridge, with the values of 94.8%, 94.3% and 92.5%, respectively, followed by in treatment intercropping Glycine max (66.0%) and Raphanus sativus (77.5%), with horizontal planting being better than vertical planting, and the lowest in treatment without understory vegetation (33.1%). The observations on the precipitation redistribution of 43 rainfall events with a mean precipitation of 20.07 mm in 2009-2010 showed that the throughfall, stemflow, and canopy interception were 9.15, 4.72 and 6.20 mm, accounting for 44.7%, 25.7% and 29.6% of the precipitation, respectively. The throughfall and stemflow tended to increase with increasing precipitation. There was a significant liner negative correlation between the canopy interception rate and the precipitation when the rainfall was less than 10 mm, but no significant correlation when the rainfall was greater than 10 mm. The water holding rate of C. reticulata litters was logarithmically correlated with water soaking time, and the maximum water holding rate was 326%. It was considered that rational allocation of understory vegetation played an important role in the soil and water conservation of citrus orchard on slope red soil.