【摘要】 <正> 我们于1976—1979年连续四年在陕西延安地区进行飞机播种造林种草试验,总面积79,000余亩。现将试验研究结果总结如下。一、试验区的自然概况试验区设在延安地区东南部的宜川县和西北部的吴旗县。宜川飞播试验区位于县城(东经110°10′,北纬36°03′)南部的铁龙湾林场和西部的英旺林场。播区属黄龙山余脉,海拔900—1250米,坡度16°—30°,土壤为褐色土。天然植被主要有黄刺梅、狼牙刺、白羊草、大油芒、黄菅草和铁杆蒿等,间有小块山杨次生林和油松人工林,盖度0.3—0.8。年平均气温9.8℃,绝对最低温度-24.4℃,早霜10月上中旬,无霜更多还原

【Abstract】 This paper deals with the general situation of aerial sowing of trees,shrubsand herbs in Yanan prefecture,Shaanxi province,and discusses the basic con-siderations regarding the choice of species and determination of sowing time. The paper recommends the suitable species for the Loess Plateau such asPinus tabulaeformis,Astragallus adsurgens as well as Caragana microphylla. The suitable sowing time is usually at the begining of raining season,Incase,if there will be a dry year according to the weather forecast,no aerialsowing should be carried out.更多还原