摘要
【目的】探讨底部渗灌不同灌水梯度对栓皮栎容器苗水分利用效率、形态特征和养分状况的影响,以期为栓皮栎容器苗精准灌溉提供科学依据。【方法】选取栓皮栎当年生播种容器苗为研究材料,采用2种容器规格(D40容器:体积656 cm3,规格6.4 cm×25 cm;D60容器:体积983 cm3,规格6.4 cm×36 cm),设置4个灌水梯度(85%,75%,65%,55%基质饱和水质量),研究不同灌水梯度处理下栓皮栎容器苗用水量、生长、养分状况和基质电导率(EC)的变化。【结果】1)栓皮栎容器苗用水量随着灌水梯度的降低依次下降,水分利用效率没有呈现类似规律,但灌水梯度高的处理水分利用效率也较高。2)灌水梯度为饱和含水量的75%~85%时,苗木的高、地径、茎生物量、根生物量和单株生物量指标在所有处理中都达到最大。灌水梯度为饱和含水量75%和85%2个处理间的形态指标差异不显著,但二者与其他含水量更低的处理差异显著。3)处理之间在养分浓度方面无明显规律;但养分含量方面,灌水梯度为基质饱和含水量75%和85%2个处理的单株和各器官中养分含量均显著高于其他基质含水量更低的处理,且2个处理之间的养分含量差异不显著。4)大规格容器苗木要比小规格容器苗木用水量多,但在形态和生物量方面,大规格容器的处理表现更优。在养分状况方面,大规格容器培育的苗木养分含量显著大于小规格容器培育的苗木,而养分浓度差异不显著。5)底部渗灌显著提高了基质上层的EC值,所有处理基质中层和下层的EC值无显著差异,且均显著低于上层,而灌水梯度的大小对基质上层的EC值无显著影响。本试验测定的EC值均低于危害苗木的最大EC值,不会对苗木造成不利影响。【结论】容器为D60、底部渗灌灌水梯度为85%和75%2个处理栓皮栎容器苗水分利用效率较高,2个处理之间的苗高、地径、生物量和氮、磷、钾含量等指标无显著差异,但均大于或显著大于其他处理,其基质上层的EC值均低于可能危害苗木的最大EC值。因此,从既节水又有利于苗木生长的角度考虑,栓皮栎容器苗底部渗灌的最佳灌水和容器组合为基质饱和水质量的75%和D60容器。
【Objective】This research was carried out to investigate the effects of sub-irrigation gradients on water use efficiency,morphology and nutrient status,and to provide a scientific basis for precision irrigation of containerized Quercus variabilis seedlings. 【Method】Annual containerized seedlings of Q. variabilis using two container sizes( D40 container:volume 656 cm3,specification 6. 4 cm ×25 cm; D60 container: volume 983 cm3,specification 6. 4 cm ×36 cm) were treated with four sub-irrigation gradients( 85%,75%,65%,55% saturated medium weight) to investigate the changes of water consumption,growth,nutrient status and electrical conductivity( EC) of the growing medium. 【Result 】1) The water consumption of containerized Q. variabilis seedlings decreased successively when sub-irrigation gradients dropped. The water use efficiency did not show similar patterns,but the higher sub-irrigation gradient had the higher water use efficiency. 2)The seedlings with sub-irrigation of 85% and 75% saturated medium weight reached the maximum values in height,diameter,stem biomass,root biomass and total individual biomass in all treatments,and no significant difference was found between these two sub-irrigation gradients,but higher or significantly higher than other treatments. 3) There was no obviouspattern among different treatments in nutrient concentration. However,the seedlings with sub-irrigation of 85% and 75%saturated medium weight had significantly higher nutrient content in plants or different organs than other treatments,and there was no significant difference between these two treatments in nutrient content. 4) The seedlings with large size containers had water consumption higher than those with small size containers,and displayed a better performance in morphology,biomass and nutrient content,however,no significant difference was found between different container sizes in nutrient concentration. 5) Sub-irrigation significantly increased the EC value of the upper layer of growing media. The EC value of the middle and lower layers of growing media was not significantly different from each other,but significantly lower than that of the upper layer. There was no significant difference among the treatments in the EC value of the upper layer of growing media. The EC value in our study was lower than the threshold EC value which causes harm to seedlings,and would not have harmful effect on seedlings. 【Conclusion】The seedlings with sub-irrigation of 85% and 75% saturated medium weight content with D60 container had the highest water consumption and higher water use efficiency. There was no significant between these two treatments in height,diameter,biomass,and contents of nitrogen,phosphorus and potassium,but higher or significantly higher than other treatments. Their EC values in upper layer of growing medium were lower than the threshold EC value which causes harm to seedlings. Therefore,in terms of water saving and growth promotion,the optimal treatment was D60 container with sub-irrigation of 75% saturated medium weight.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2015年第7期21-27,共7页
Scientia Silvae Sinicae
基金
"948"计划资助项目(2012-4-66)
林业公益性行业科研专项经费项目(201004021)
关键词
栓皮栎
容器苗
底部渗灌
灌水梯度
Quercus variabilis
containerized seedlings
sub-irrigation
sub-irrigation gradients