2003 Volume 45 Issue 1 Pages 13-19
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 3.8Mg ha^<-1>. The root biomass of each LCC was almost at a similar amount to 1.7Mg ha^<-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.
