【摘要】 玉米是需水较多的作物,对水分代谢的临界期在开花前8￣10d开始的约30d之内。半干旱地区旱作地膜玉米的主要障碍因子是“干旱缺水”,降水高峰期在小暑至立秋的约30d时间,拔节后的水分供应唯一靠自然降水。因此,确定半干旱地区旱作地膜玉米的最佳播期,应以“降水高峰期”因子为主要指标,即应用“调水说”播期理论。更多还原

【Abstract】 Corn is the crop, which needs much water. The critical stage of moisture metabolism is within 30 days beginning with 8-10 days before blooming. The main obstacle factor in arid and semi-arid area is "dry and lack of water". The natural rainfall boom takes place in time of 30 days between Slight Heat and Beginning of Autumn and the moisture supply after corn’s jointing only depends on natural rainfall. Therefore, to determine the optimum sowing time of corn in arid and semi-arid areas, the factor of rainfall boom should be considered as the key to the question, that is, the theory of precipitation-regulating should be applied.更多还原