森林立地学会誌 森林立地45(1),2003,13〜19
Jpn.J.For.Environment
45(1),13-19 2003
Legume cover crop as soil
amelioration at a short
rotation plantation in a
tropical region
Cahyono Agus＊,＊＊, Oka Karyanto＊＊, Suryo Hardiwinoto＊＊,
Satoshi Kita＊＊＊, Kikuo Haibara＊＊＊, Hiroto Toda＊＊＊and Hirohiko Minematsu＊＊＊
＊United Grad. School of Agric. Sci., Tokyo Univ. of Agric. and Technol.,
Fuchu 183-8509, Japan
＊＊Faculty of Forestry, Gadjah Mada University,
Yogyakarta, Indonesia
＊＊＊Faculty of Agriculture, Tokyo Univ. of Agric. and Technol.,
Fuchu 183-8509, Japan
The effects of legume cover crop (LCC) on the soil chemical properties in a tropical region were studied to clarify the possibility of soil amelioration for a short rotation plantation forest. Three species of legume: Crotalaria anagyroides (CA), Mucuna chochuchinensis (MC) and Calopogonium caeruleum (CC) were planted at the clear cutting area after the Gmelina arborea Roxb (yemane) plantation (6 year-old). The biomass of LCC was measured 4 months after planting (MAP) when biomass of LCC seemed to be at a maximum. Soil chemical properties under the LCC were examined at 6 MAP. Total biomass (aboveground plus belowground) in CA was 4.7, MC was 4.3 and CC was 3.8Mgha-1. The root biomass of each LCC was almost at a similar amount to 1.7Mgha-1. The nutrient amounts in the total biomass per hectare were 67 to 78kg for N, 27 to 33kg for K, 15 to 23kg for Ca, 2 to 3kg for Mg and 0.3kg for Fe at 4 MAP. The total nutrient amounts per hectare in topsoil (0 to 10cm) under the LCC and the control plots were almost same. The exchangeable Ca and Mg in the CA and MC plots were about twice the amount, while the exchangeable Al was half of the control plot. There were no differences in exchangeable Ca between CC and the control plots. The legume could be cultured for two rotations in a year in a tropical region, so LCC was expected to affect the soil amelioration at a short rotation plantation forest.
Key words: legume cover crop, organic matter, short rotation plantation, soil amelioration, tropical forest
Cahyono Agus, Oka Karyanto, Suryo Hardiwinoto, 喜多 智，生原 喜久雄，戸田 浩人，峰松 浩彦：熱帯地域における短伐期造林での土壌改良としてのマメ科植物の植栽
熱帯地域でのマメ科植物の被覆が短伐期育成林の土壌の化学性質に及ぼす影響について調査した。３種のマメ科植物，Crotalaria anagyroides (CA)，Mucuna chochuchinensis (MC) ，Calopogonium
caeruleum (CC)を６年生で皆伐したGmelina arborea Roxb (yemane) の伐採地に植栽した。植栽４ヶ月後にマメ科植物のバイオマスを，６ヵ月後に表層土壌（0〜10cm）の化学性を調査した。全バイオマスはCAで4.7 Mgha-1，MCで4.3 Mgha-1，CCで3.8 Mgha-1，根のバイオマスは３種とも1.7 Mgha-1であった。バイオマス中の養分量は，Nで67〜78kgha-1，Kで27〜33 kgha-1，Caで15〜23 kgha-1，Mgで2〜3 kgha-1，Feで0.3 kgha-1であった。表層土壌中(0〜10cm)のha当たりの全養分量は、マメ科植物および無処理に違いが見られなかった。CAおよびMCの交換性 CaおよびMg量は無処理区の約2倍，交換性Alは約半分であった。CCと無処理との間には交換性Caに違いは見られなかった。熱帯地域ではマメ科植物を年2回栽培が可能なので，マメ科植物による地表面の被覆は短期育成の施業林において土壌改良としての効果が期待される。