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辽宁省西北部半干旱地区是广阔的欧亚中纬度干旱、半干旱地区的东缘南段。总面积约为2.81万平方公里,占全省总土地面积的20％左右,共有耕地1700万亩;平均每人占有耕地3～10亩以上,是该省人少地多的地区。 全区地势西高东低。年平均气温在7～9℃之间,年≥10℃积温在3200℃～3600℃之间,无霜期130～170天,年日照时数2400～3000小时,太阳年辐射量在130大卡/平方厘米·年左右。年降水量在500毫米左右。作者分析了七个县20多年的年降水量与粮食亩产量的关系,指出:年降水量不足400毫米,则亩产量明显下降;当年降水量小于300毫米时,则严重减产。朝阳县29年的资料,年降水量小于400毫米的共有7年,其亩产量都在180斤以下。 本区耕作制度改革的主要途径是: 1、造林种草,防止水土流失;改广种薄收为精耕细种、少种,高产多收。 2、确立防旱、防风蚀、防水蚀的“三防”土壤耕作制。 3、扩大抗旱作物、增种经济作物,调整作物布局,作到稳中求高,增产增收。 4、发展灌溉是提高产量的有效途径。
The semi-arid region in the northwest of Liaoning Province is the vast southern margin of the eastern margin of the arid and semi-arid region in the mid-latitude Europe and Asia. The total area of about 28,100 square kilometers, accounting for about 20% of the total land area of the province, a total of 1700 acres of arable land; the average per capita possession of 3 to 10 acres of arable land, is the province less land and more areas. The high-lying east west low. The annual average temperature is between 7 ~ 9 ℃, the annual temperature ≥10 ℃ accumulated temperature between 3200 ℃ ~ 3600 ℃, frost-free period of 130 to 170 days, the annual sunshine hours 2400 ~ 3000 hours, the annual solar radiation at 130 kcal / square Centimeters or so. Annual precipitation at about 500 mm. The author analyzed the relationship between annual precipitation and grain yield in 20 years of seven counties, and pointed out that when the annual precipitation is less than 400 mm, the yield per mu obviously drops; when the precipitation is less than 300 mm in the same year, the yield is seriously reduced. 29 years of information in Chaoyang County, a total annual rainfall of less than 400 mm for a total of seven years, the mu yield of 180 pounds or less. The main ways of farming system reform in this area are as follows: 1. Afforestation and planting of grass to prevent soil erosion; change narrow planting to fine cultivating and planting less and yield more. 2, to establish drought prevention, wind erosion, water erosion of the “three defenses” soil cultivation system. 3, to expand drought-resistant crops, increase economic crops, adjust the crop layout, so as to seek stability, increase production and income. 4, the development of irrigation is an effective way to increase production.