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通过调查东北玉米主产区梨树县气温、降雨变化与玉米产量的相关关系,明确该地区玉米大面积高产的水热限制因子。分析了近23年(1986～2008年)来梨树县光照、温度、降雨的变异特征及其对玉米产量变异的决定作用。玉米生长期(5～9月)气温不断升高,积温值已达3145℃。降雨量则呈显著下降,从1986年的637毫米稳定下降到1992年的442毫米,此后16年来的玉米生长季平均降雨维持在443毫米左右,但年际间的变异幅度急剧增大。玉米产量与5月上旬(播种出苗期)、6月下旬(拔节期)、7月下旬(抽雄期)三个生育时期的降雨量呈极显著正相关。温度升高(尤其是5月上旬及6月下旬)会加重土壤水分蒸发,因而温度与产量呈负相关。干旱年份,玉米干物质积累从出苗后30天就受到抑制。降雨量不足是限制梨树地区玉米产量的主要因子。在该地区现有的栽培条件下,当降雨量达到500毫米左右时,产量水平为666.7千克/亩左右,水分(降雨)生产效率达到1.25千克/(亩.毫米)。要进一步大面积提高玉米产量,必须改进栽培耕作措施,提高水分生产效率。
By investigating the correlation between temperature and rainfall in Lishu County, a major producing area of northeastern China, and corn yield, the hydrothermal limiting factor of large area and high yield of corn in this area was determined. The variation characteristics of light, temperature and rainfall in Lireshu County in recent 23 years (1986 ~ 2008) were analyzed and their decisive roles in yield variation of maize were analyzed. Growing corn (May ~ September) temperature rising, the accumulated temperature has reached 3145 ℃. Rainfall dropped significantly from 637 millimeters in 1986 to 442 millimeters in 1992. After that, the average rainfall during the 16-year corn growing season remained at about 443 millimeters, but the annual variation range sharply increased. Maize yield was significantly and positively correlated with rainfall at the three growth stages in early May (sowing), late June (jointing) and late July (tasselling). Temperature increases (especially in early May and late June) increase soil moisture evaporation and thus temperature and yield are negatively correlated. In dry years, dry matter accumulation in maize was inhibited from 30 days after emergence. Low rainfall is a major factor limiting maize production in the pear area. Under the existing cultivation conditions in the area, the yield level is about 666.7 kg / acre when the rainfall reaches 500 mm and the production efficiency of moisture (rainfall) is 1.25 kg / (mu. Mm). To further large-scale increase corn production, cultivation and cultivation measures must be improved to improve water production efficiency.