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本文试从气象角度对大宁县春玉米的适期早播,进行探讨。一、春玉米适期早播的必要性大宁县地处晋西黄土丘陵沟壑区,由于受季风气候影响,降雨分配很不平衡,从而形成了阶段性干旱。首先是春早,春季少雨多风,气温回升快,相对湿度小(历年平均为149%,8年中有5年小于30%),常给玉米播种带来困难,一般年份缺苗20—30%,重旱年份缺苗达50—60%。再则是伏旱,17年中,中伏旱有7年,末伏旱有9年,最严重的是“卡脖旱”。玉米从播种到抽雄,一般需要70—80天时间。大宁春玉米的习惯播期是4月中、下旬,结果常常遇旱,致使抽雄困难,花粉发育不良.生活力降低,不易授粉,形成秃尖,造
This paper tries to study the suitable seeding of spring maize in Daning County from the meteorological point of view. First, the need for early maturity of spring maize Daning county is located in loess hilly and gully areas, due to monsoon climate, the distribution of rainfall is very uneven, resulting in a phased drought. The first is early spring, the spring less rain and more wind, the temperature rise faster, the relative humidity is small (calendar year average of 149%, 8 years less than 30% of 5 years), often to corn planting difficulties, the general lack of seedlings 20-30 %, Severe drought years lack of seedlings up to 50-60%. In the meanwhile, it is aridity. In 17 years, there is a 7 years drought in the middle and a 9 years drought in the last. The most serious problem is “drought in the card neck.” Corn from sowing to tasseling, usually takes 70-80 days time. Daning spring corn sowing is mid-April, late, often the result of drought, resulting in difficult tassel, pollen dysplasia .Life, less pollination, the formation of bald sharp, made