本文以河南省封丘县鲁冈乡境内的泡桐-小麦-玉米(paulownia-wheat-maize)间作为研究对象，对农桐间作系统的土壤养分与小气候，林木与农作物的生物生产力等进行了系统测定；分析了林带间环境因子与农作物产量之间的相互关系；运用Logistic曲线拟合林带内农作物产量，设计了农桐间作的最优行距，为探讨农林复合系统的结构优化提出了新方法。

The interplanting system of paulownia with crops is a main model of agroforestry managementin Huanghuaihai plain of China. A seven- year- old complex system of paulownia (Paulownia elungata S. Y. Hu) interplanted with wheat and maize in Fengchiu Testing Area was comprehensively researched. Compared with the monocropping system, the complex system had higher productivity, more stable microclimate condition, and higher level of nutrient content of soil. It was found that solar radiation was the dominant factor influencing the crop yield in the complex system. Logistic equation was used to estimate the crop yield in the complex system as follows: F =K/ (1 +AE^-BX)for wheat and F =K/ (1+E^{AX2+ BX+C}) for maize, X (m ) , distance from shelterbelt; Y (kg/m² ) , crop yield. By integrating the imitated logistic equation, we could estimate the total crop yield in various structures of complex systems. Moreover, by establishing a equation group, we could calculate the optimized row distance, it was 55 meters at which the interplanting system would acquire highest economic, ecological and social benefits.