辽北地区杨树-玉米间作对土壤水分和养分含量的影响

Effects of poplar-maize intercropping on soil moisture and soil nutrient contents in northern Liaoning of China

东北地区有大量的农林间作系统，了解其土壤水分和养分的分布特征对于农林间作系统的持续经营和生产力的提高具有重要意义。本研究以辽宁省付家机械林场的杨树-玉米间作系统为对象，以玉米单作系统为对照，对玉米收获后的土壤水分和养分分布特征进行了调查。结果表明：杨树-玉米间作显著降低了0～100 cm各层土壤含水率，提高了10～100 cm土层土壤无机氮含量和0～50 cm土层土壤有机氮含量，增加了土壤有机碳、全磷含量在0～30与30～100 cm土层分布的差异。间作改变了土壤水分、养分元素之间的相关关系。在玉米单作系统中，土壤有机氮、有机碳、全磷含量与土壤含水率、土壤无机氮含量均存在显著的相关性，而在间作系统中土壤含水率和无机氮含量与土壤有机氮、有机碳、全磷含量相关性较弱。本研究可为辽北地区农林间作系统土壤水分和养分的管理提供科学依据，并为进一步探讨该地区间作系统土壤养分循环奠定基础。

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.