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団粒の大きさを異にする5種類の用土を用い施肥法, 肥料形態の相違がポットマムの生育に及ぼす影響を検討し以下の知見を得た.用土の物理性を検討したところ, ミジンを除くことによって, 田土, 赤土区ともに気相率が増大したが, 液相率は減少した.田土はpF 2.7-3.8, 赤土はpF 2.0-2.7およびpF 4.2以上に孔隙分布のピークがあり, ミジンを除くことによりpF 1.0以下の孔隙率が高まった.溶脱水のECは元肥区のとくに初期において高く, また粒径が細かいほど高かった.養分の溶脱量は田土区より赤土区で, 追肥区より元肥区で多く, 大粒径区ほど減少した.チッ素の溶脱は前半はNH_4-N, 後半はNO_3-Nが主体であった.ポットマムの生育は赤土区より田土区で良好で, 元肥区, 追肥区の差は判然としなかった.一方, 粒径区間では除ミジン区の生育が不良であった.その原因は初期における塩類濃度障害と思われ, それをさける方法としてCDU肥料の利用の可能性が示唆された.除ミジン区の根群はミジンを含む区に比べ鉢内下層に分布が多く, また塩類濃度は全般に高いうえ, 特に上層において高く維持されていた.

Studies on Composts and Fertilization in Pot-Plant Culture. V. Effects of Physical Properties of the Composts, fertilizer Application Methods and Fertilizer Forms on the Growth of Pot Mums (Chrysanthemum morifolium Ramat.). Yukio SATO, Noritsugu SHIMADA, Nobuyoshi SAKAKIBARA and Michiya KOJIMA. Faculty of Horticulture, Chiba University, Matsudo, Japan. Tech. Bull. Fac. Hort. Chiba Univ., No.25: 13-19, 1977. The present experiments were carried out to clarify the effects of different methods of fertilizer application (basal, top-dressing) and fertilizer forms (slow-releasing, liquid) on the growth of pot mums grown in different soils varying in the particle size (5mm>, 5-1mm, 5-3mm, 3-1mm, 1mm>). The results obtained were summarized as follows: The porosity of the potting compost corresponding to the range from pF 0 to pF 1.0 increased and liquid phase decreased with increasing soil particle size in the compost. The highest value in the pore distribution pattern of the fine-particled paddy loam soil composts (5mm> and 1mm> in size) was observed in the range from pF 2.7 to pF 3.8. In the case of fine-particled volcanic ash soil composts, two peaks of soil pore were observed in the range from pF 2.0 to pF 2.7 and above pF 4.2. On the other hand, soil pore in the coarse-particled composts was increased markedly in the lower values than pF 1.0. EC values of leached solution from composts were highest during early 10 days of the experimental period, especially in the basal fertilizing plots and the fine-particled composts. The amount of leached nutrients from volcanic ash soil composts was greater than those from paddy loam soil composts, and it was also greater in the basal fertilizing plots than in top-dressing plots. In this case, it is interesting to note that a greater leaching was observed from the composts containing the finest-particled soil, as compared to that from the composts excluding the finest-particled soil. Leached nitrogen forms from the composts were mainly NH_4 in the earlier period and NO_3 later i

source:The technical bulletin of Faculty of Horticulture, Chiba University