The Influence of Larch-soybean Intercropping on the Growth Characteristics of Xingan larch Plantations in Northeast China

The objective of this study was to investigate the capacity for soil fertility improvement and larch growth promotion in a larch-bean intercropping system involving Xingan Larch (Larix gmelinii Rupr.) and soybean (Glycine max (L.) Merr.) in northeast China. Compared to the larch only plot, the larch-soybean intercropping had decreased soil bulk density, increased soil porosity and water content. It also significantly increased the soil organic matter, and there was found an increasing in soil nutrient content including available nitrogen, phosphorous and potassium. As a result of these soil improvements after soybeans were added to the larch plantations, greater height and diameter growth rates were observed in larch trees. The light saturated net photosynthetic rate of larch in a 9 year-old larch-soybean plot was 8.25 µmol m-2s-1, but it was only 7.2 µmol m-2s-1 in 9 year-old pure larch plots