关于单株玉米耗水量的探讨

一株玉米一生究竟需要消耗多少水,目前尚无定论。国内外许多著作中,一株玉米一生蒸腾耗水量常常引用"200kg"这一数据。在《中国玉米栽培学》中,则提出了蒸腾耗水量为80kg/株,两者相差2.5倍。文章通过中国科学院禹城综合试验站大量的玉米农田蒸发实验数据,分析了生长在自然条件下单株玉米的蒸腾耗水量和玉米平均总耗水(包括蒸腾量和棵间蒸发量),得到如下结果:①单株春玉米的总耗水量为100kg/株左右,蒸腾耗水量为60kg/株左右;②华北平原夏玉米总耗水量为50~80kg/株,蒸腾耗水量为30~40kg/株;③只要土壤水分不出现长期干旱,土壤水分状况不会对单株玉米耗水量产生大的影响;④种植密度对单株玉米需水量产生重大影响,当玉米种植密度由5.0×10⁴株/hm²增至10.0×10⁴株/hm²时,总耗水量仅增加13.18%,而单株耗水量减少了44.48%。这些数据可供参考。

An Investigation on Water Consumption of an Individual Plant of Corn

How much water for an individual plant of corn does cost? There is no conclusion so far worldwide. Many literatures have frequently cited the number of "200kg" as the whole water consumption for an individual plant of corn in entire growth period. In the monograph of "Corn Cultivation in China", the water consumption of corn by transpiration is 80kg/plant, which is two and half times difference with the former number mentioned. By analyzing the data collected at the Yucheng Comprehensive Experimental Station, CAS, the author studied the water consumption for an individual plant of corn and the average total water consumption (including transpiration and evaporation among plants) under the natural growth condition. The following results were concluded: 1) Water consumption for an individual plant of spring corn is about 100kg/plant and transpiration is about 60kg/plant. 2) Total water consumption for summer corn in North China Plain is 50-80 kg/plant and transpiration is 30-40 kg/plant. 3) Water condition in soil has no great influence on water consumption for an individual plant of corn unless the long-term drought happening. 4) The density of corn planting impacts the water consumption greatly. When the density of corn planting increased from 50,000 plants/ha to100,000 plants/ha, the total water consumption increased only 13.18%. Meanwhile the water consumption for an individual plan decreased by 44.48%.