Studies on the nutritional characteristics of plants adapted to low pH soils.

为了阐明植物适应低pH土壤的营养特性，对生长在冲积土(北海道大学植物园)、酸性土和蛇纹土上的植物叶片中的养分含量进行了比较。在叶片主要养分中，N、P、K含量在土壤间变异较小，钙含量在酸性土壤和蛇纹土中低于冲积土壤，镁含量在酸性土壤中低于冲积土壤，或在蛇纹土壤中高于冲积土壤。在叶片中的微量元素中，酸性土壤中铁含量低于冲积土，而蛇纹土中锰含量高于冲积土。预计在酸性土壤中铝含量较高，而在高pH土壤(蛇纹土)中铝含量较低，但叶片中铝含量在不同土壤中的变化趋势并不一致，说明铝含量反映的是植物自身的特性，而不是土壤性质。结果表明，叶片中的N、P、K、Al营养成分受植物自身的营养特性…调控另一方面，叶片中的钙、镁、铁、锰养分受土壤养分的影响。在泰国半岛南部，分布着酸性硫酸盐、泥炭、沙质坡缕土和盐碱地等不利土壤。在低pH和泥炭土中生长的优势植物是野牡丹和野千层。马拉巴斯曼在叶片中积累了大量的铝，特别是在新生的叶片中，因此，马拉巴斯曼被指定为铝积累植物。而彩叶锦鸡儿不会在地上部积累铝，因此它是典型的排铝植物。因此，M.Malabathricum和M.cajuputi很好地适应低pH土壤，而它们对Al有不同的策略。当低pH耐性植物(特别是马来支原体和卡珠藻)在pH为4.0的3个铝水平的Al-P平衡体系中进行水培培养时，这些植物在施铝条件下生长良好，不能吸收磷和氮，表明铝是铝积累植物和铝排斥植物特别是磷吸附的重要元素。较少

To elucidate the nutritional characteristics of plants adapted to low pH soils, nutrients content in leaves was compared among plants grown in alluvial soil (Botanical garden of Hokkaido University), acid soil, and serpentine soil. Among macro nutrients in leaves, variation of N,P,and K content was small among soils, Ca content was lower in acid soil and serpentine soil than in alluvial soil, and Mg content was lower in acid soil, or higher in serpentine soil than in alluvial soil. Among micro nutrients in leaves, Fe and Mn content was lower and higher, respectively in acid soil and serpentine soil than in alluvial soil. It is expected that Al content will be high in acid soils, and will be low in high pH soil (serpentine soil), however Al content in leaves did not show the consistent tendency among soils, indicating that Al content reflect on the plant own characteristics, not on soil properties. As a results, N,P,K,Al nutrients in leaves are regulated by plant own nutritional charact … More eristics, on the other hand, Ca, Mg, Fe, and Mn nutrients in leaves are affected by soil nutrients.In Southern Peninsular Thailand, adverse soils such as ; acid sulfate, peat, sandy podozol, and saline soils are distributed. Melastoma malabathricum and Melaleuca cajuputi were dominant plants grown in low pH and peat soils. M.malabathricum accumulated the huge amount of aluminum (Al) in leaves, especially in new growing leaves, therefore, M.malabathricum is designated as Al accumulator plant. While, M.cajuputi did not accumulate Al in shoot, therefore, M.cajuputi is designated typically as Al excluder plant. Thus, M.Malabathricum and M.cajuputi adapt well to low pH soils, while they have a different strategy for Al. When low pH tolerant plants (especially M.malabathricum and M.cajuputi) were hydroponically cultivated in Al-P equilibrium system with 3 Al levels at pH4.0, these plants grew well by Al application, and could not absorbed phosphorous and nitrogen without Al, indicating that Al is important element for especially phosphorous adsorption in both Al accumulator plants and Al excluder plants. Less