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本文将陕北黄土高原分为6个农业生态经济系统,笔者从土地利用结构、生物群落、产值结构、能量在食物链中流动和转化效率、粮田氮素循环、作物水分利用率、水土保持效益等方面来分析各系统的生产力,通过典型事例来论证观点,并指出今后发展的方向。从现状分析结果来看,以延安市庙沟为代表的梁状丘陵果林农牧系统,由于大力发展苹果生产,经济效益最高,1990年人均纯收入达1166.7元,比周围村高1.9倍,目前百亩果园供养44.6人,比百亩草地供养人数高8.3倍,至1995年可供养217人。以米脂县泉家沟为代表的峁状丘陵果粮副牧系统,由于大搞农田基本建设和退耕还林种草,年土壤侵蚀模数由60年代的16000t/km~2降低到3000t/km~2,1990年人均纯收入656.4元,比周围村增加1倍,目前百亩果园供养95人,比种粮食多供养9.1人,至1995年可供养190人。
This paper divides the Loess Plateau in North Shaanxi into six agricultural eco-economic systems. The author analyzes the land use structure, biological community, output structure, energy flow and conversion efficiency in the food chain, grain nitrogen cycling, crop water use efficiency, soil and water conservation benefits And other aspects to analyze the productivity of each system, through typical examples to demonstrate the point of view, and pointed out the direction of future development. Judging from the status quo, the results show that the Liangzhuoling fruit and vegetable farming system represented by Miaogou in Yan’an City has the highest economic benefit due to its vigorous development of apple production. In 1990, the per capita net income reached 1166.7 yuan, 1.9 times higher than that of the surrounding villages. Currently, Baimu Orchard to support 44.6 people, 8.3 times higher than the number of acres of grassland support, to support 217 people in 1995. Because of the farmland construction and returning farmland to forest and grassland, the annual soil erosion modulus is reduced from 16000t / km ~ 2 in the 1960s to 3000t / km ~ 2. In 1990, the net income per capita was 656.4 yuan, twice as much as that of the surrounding villages. At present, 95 acres are served with 100 acres of orchards and 9.1 more than that with food grains. By 1995, 190 people can be raised.