Abstract: A great amount of tree-based intercropping systems has been established in Northeast China. Understanding the distribution patterns of soil moisture and soil nutrients of treebased intercropping systems can be beneficial to the ecological sustainability and productivity improvement of tree-based intercropping systems. An investigation was conducted in poplar-maize intercropping and maize monoculture systems in Fujia Mechanical Forest Farm in Liaoning Province to examine the effects of treebased intercropping on the distribution of soil moisture and soil nutrients after maize harvesting. Results showed that intercropping  led to a significantly lower soil moisture in the 0-100 cm soil layer, higher soil inorganic nitrogen content in the 10-100 cm soil layer and higher soil organic nitrogen content in the 0-50 cm soil layer, and also increased the difference of soil organic carbon, total phosphorus contents between the 0-30 cm soil layer and the 30-100 cm soil layer. Furthermore,  intercropping  altered the correlations of soil moisture and soil nutrients. Soil organic nitrogen, organic carbon and total phosphorus contents significantly correlated with soil moisture and soil inorganic nitrogen content in the maize monoculture system, while weakly correlated with these variables in the poplar-maize intercropping system. These results provide scientific guidance for soil water and nutrient management of tree-based intercropping systems, and lay a foundation of further study of soil nutrient cycling in agroforestry systems in northern Liaoning Province.

Key words: paddy soil, fertilization, bacteria, archaea, diversity.