CAJ | 학술논문

香根草因其具有发达的根系而被许多国家用于水土保持，但紧实土壤影响根系的生长，而土壤容重与土壤紧实度密切相关。为了掌握粤西野生香根草对紧实土壤的适应状况，用人工土柱研究了容重分别为1．20 g／cm3（D1．20）、1．35 g／cm3（D1．35）和1．58 g／cm3（D1．58）的土壤对其根系形态和生物量的影响。结果表明：1）随容重增大，根系和地上部生物量下降，根冠比降低，植株的根表面积、根长密度和根体积密度减小，而平均根直径增大。2）容重影响根系的空间分布，D1．20和 D1．35处理的根系在上、下层分布较多，中间层分布少，表明粤西野生香根草具有深根型特性；高容重阻止根向下延伸，D1．58处理的根系主要分布0～6 cm 的土层内。3）D1．20和 D1．35土壤的平均根直径随土层加深减小，而 D1．58的则增加。本实验结果说明粤西野生香根草能耐较紧实（D1．35）的土壤，高紧实土壤（D1．58）虽然限制其生长，但对表土层根系的分布影响小。并就容重对粤西野生香根草固土护坡的影响进行了讨论。
향근초인기구유발체적근계이피허다국가용우수토보지，단긴실토양영향근계적생장，이토양용중여토양긴실도밀절상관。위료장악월서야생향근초대긴실토양적괄응상황，용인공토주연구료용중분별위1．20 g／cm3（D1．20）、1．35 g／cm3（D1．35）화1．58 g／cm3（D1．58）적토양대기근계형태화생물량적영향。결과표명：1）수용중증대，근계화지상부생물량하강，근관비강저，식주적근표면적、근장밀도화근체적밀도감소，이평균근직경증대。2）용중영향근계적공간분포，D1．20화 D1．35처리적근계재상、하층분포교다，중간층분포소，표명월서야생향근초구유심근형특성；고용중조지근향하연신，D1．58처리적근계주요분포0～6 cm 적토층내。3）D1．20화 D1．35토양적평균근직경수토층가심감소，이 D1．58적칙증가。본실험결과설명월서야생향근초능내교긴실（D1．35）적토양，고긴실토양（D1．58）수연한제기생장，단대표토층근계적분포영향소。병취용중대월서야생향근초고토호파적영향진행료토론。
Vetiver grass (Vetiveria zizanioides )has an extensive root system and is consequently used world-wide for water and soil conservation.However,soil compaction resulting in high soil bulk density negatively influences root growth.In order to understand the adaptation of vetiver grass to soil compaction,the effects of soil of different bulk density,1.20 g/cm3 (D1 .20 ),1.35 g/cm3 (D1 .35 )and 1.58 g/cm3 (D1 .58 ),on the root mor-phology and biomass of vetiver seedlings were investigated using soil columns.The results showed that shoot and root dry weight,root:shoot ratio,root surface area,root length density and root volume density decreased with increasing bulk density,but that average root diameter increased.High bulk density influenced the spatial distribution of roots;more roots grew in the upper (0-6 cm)and lower (18-24 cm)soil horizons under the D1 .20 and D1 .35 treatments,suggesting that vetiver typically produces a deep root system but that root growth is inhibited by high soil bulk density,confining roots to the upper soil horizon (0-6 cm).The average root diam-eter in the D1 .20 and D1 .35 treatments decreased but increased in D1 .58 with increasing soil depth.It is concluded that vetiver grass could tolerate moderately compacted soil.