农林复合系统结构优化的研究

对河北饶阳试区的土地利用方案和１０种类型的果—农间作体系的合理配置进行了研究，通过计算机数据处理，从中筛选出优化的结构模式和土地利用方案。结果表明：①农林复合生态系统中土地优化利用方案的规划应该考虑市场的价值变动，还应该考虑到在林木的生长前期投入与经济效益的问题。②发展的农、林产品有梨树、油菜和棉花。③雪花梨和鸭梨为主的模式，其最佳栽植模式是株行距为３ｍ×５ｍ，两行或三行为一带，带距为３０ｍ。④果—农模式体系中农作物品种的配置以小麦—蔬菜组合为最好，产投比为２．７∶１；其次为油菜—蔬菜组合；粮食类较好组合有小麦—薯类、小麦—玉米、小麦—谷子、小麦—黄豆、油菜—玉米等。

Study on the Optimum Structure of Agroforestry

The results show that:(1) Price fluctuation of agriculture and forest products should be considered in planing the optimum use of land.(2) The appropriate species in agroforestry system are pear,rape and cotton. (3) The appropriate structure are two pear hybrids (Pyrusbretschneideri Rehd) intercropping model with a spacing of 3 m×5 m. Forest belts are composed of two or three rows of trees and the distance between belts is 30 m.(4)The optimum compound of crop species in fruits-crops model is wheat-vegetable.The rate of output value to invested capital is 2.7:1. Other compounds of crop species are wheat-yam ,wheat-corn,wheat-millet,wheat-beanand, rape-corn etc.