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渭南县是陕西棉花生产基地之一,种植面积35.5万亩,棉花占农业总产值的40％。但33年来,单产徘徊在50斤左右。影响棉花生产的因素很多,但主要的是春旱、伏旱和秋涝,其中以伏旱为最甚。一、伏旱威胁棉花生产 1.据统计,1933—78年46年间渭南县伏旱和伏、秋旱出现40次,平均1.15年出现一次。20天以上的伏旱21次,平均2年一遇;旱期在30天以上的严重伏旱15次,平均3年一遇。1943—1947年、1966—1972年,都是连续5—7年伏旱,旱情甚为严重。1959—81年23年中,渭南县棉花亩产在50斤以下的共13年,其中因伏旱减产的达9年,占69.2％,可见,伏旱是影响棉花产量的主要因素。
Weinan County is one of the cotton production bases in Shaanxi Province with a planting area of 355,000 mu and cotton accounting for 40% of the total agricultural output. However, in the past 33 years, yields have hovered around 50 pounds. There are many factors affecting the cotton production, but the main ones are spring drought, summer drought and autumn flood, among which the summer drought is the worst. First, the drought threatened cotton production 1. According to statistics, 1946-1974 Weinan County, drought and volt, autumn, drought appeared 40 times, an average of 1.15 years once. The drought of more than 20 days was 21 times with an average of 2 years. Severe drought with a dry period of more than 30 days was 15 times with an average of 3 years. In 1943-1947 and 1966-1972, there was a continuous 5-7 year drought and the drought was very serious. In the 23 years from 1959-81, the Weinan cotton yield was less than 50 pounds per mu for 13 years, of which the yield was reduced by 69.2% due to drought and drought. It can be seen that the drought was the main factor affecting the cotton yield.