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我区地形复杂,气候多变。为使作物布局趋于合理,现提几点初步意见,以就教于读者。一、选用抗旱作物我区年降雨量南大于北。南部约550毫米,北部约400毫米,多集中在7—9月,冬、春雨少,常年春旱。延安市26年的统计,春旱概率为92％。有的年份春夏、夏秋连早。1971年,延安北9县春旱,面积达231.2万亩,夏日减产2428万斤,秋田缺苗42.9万亩,缺苗翻种11.3万亩。因此,选用抗旱作物是个重要问题。本区抗旱作物可分三类:一是本身具有较高的抗旱力,如谷、糜耗水量少,凋萎系数低,谷子发芽吸水量为种子重的25％,比小麦低2倍,比高粱低3倍,比水稻低4倍。壤土
My area has complicated terrain and varied climate. In order to rationalize the crop layout, I will make a few preliminary comments to teach readers. First, the selection of drought-resistant crops in our region south of the north than the rainfall. About 550 mm in the south, about 400 mm in the north, and more concentrated in the July-September, winter, less spring rain, perennial spring drought. According to statistics of 26 years in Yan’an City, the probability of spring drought is 92%. Some years spring and summer, summer and early morning even. In 1971, 9 counties in northern Yanan spring drought, an area of 231.2 hectares, 24.28 million kilograms in summer, lack of seedlings Akita 42.9 hectares, 11.3 hectares of seedlings missing seed. Therefore, the selection of drought-tolerant crops is an important issue. Drought-resistant crops in this area can be divided into three categories: First, itself has a higher drought resistance, such as valley, Mi less water consumption, withered coefficient is low, millet germination and water absorption of 25% of seed weight, 2 times lower than wheat, Sorghum 3 times lower, 4 times lower than rice. Loam