不同程度干旱对春玉米生物量和产量影响的模拟

Simulating the impact of drought on spring maize biomass and yield

为了探究不同强度干旱对春玉米生长过程和产量形成的影响,本文基于WOFOST作物生长模型,分析了内蒙古地区春玉米在拔节-抽雄期和抽雄-乳熟期分别发生不同程度干旱对生物量和产量的影响。结果表明：随着干旱程度的加重,春玉米的灌浆强度、产量、生物量增长量和生物量的降幅均随之加大;复水后,灌浆强度和生物量增长量迅速恢复至无旱水平;相比无旱处理,在轻旱、中旱和重旱处理下,灌浆强度分别下降14.8%~15.4%、40.9%~42.9%和52.4%~60.8%,产量分别下降1.9%~6.1%、9.5%~15.4%和18.6%~25.8%,生物量增长量分别下降12.6%~12.8%,31.0%~35.5%和50.4%~50.8%,生物量分别下降2.9%~6.1%、6.9%~19.4%和12.0%~32.1%;拔节-抽雄期和抽雄-乳熟期两个生育阶段干旱影响的灌浆时段不同,抽雄-乳熟期干旱同时影响灌浆高峰期和衰减期的灌浆强度,故其导致的产量损失更为严重;这2个生育阶段干旱分别影响同化物积累的高峰期和衰减期,拔节-抽雄期干旱影响时间更长,生物量的降幅更为明显。

Based on WOFOST crop growth model,we simulated the impacts of different drought intensities during jointing to tasseling and tasseling to milk-ripe stages on spring maize biomass and yield in Inner Mongolia. The results showed that the rates of grain-filling intensity,yield,biomass increment and biomass decreased with the increase of drought degree. After rewatering,the grain-filling intensity and biomass increment were rapidly restored to the level without drought. Grain-filling intensities under light drought,moderate drought and serious drought were reduced by 14. 8%- 15. 4%,40. 9%- 42. 9% and 52. 4%- 60. 8% respectively. Meanwhile,the yields were reduced by 1.9%-6.1%,9.5%-15.4% and 18.6%-25.8%,the biomass increments were reduced by 12.6%- 12. 8%,31. 0%- 35. 5% and 50. 4%- 50. 8%,and the biomasses were reduced by 2.9%-6.1%,6.9%-19.4% and 12.0%-32.1% accordingly. The grain-filling period was differently affected by droughts from jointing to tasseling and from tasseling to milk-ripe stage.The yield loss was higher when the drought occurred from tasseling to milk-ripe stage because the grain-filling intensity at peak and decline phases was both influenced at this developmental stage.The droughts from jointing to tasseling stage and from tasseling to milk-ripe stage affected the peak and decline phases of assimilate accumulation,respectively. The duration of the impact by drought from jointing to tasseling stage was longer; therefore,the descent rate of biomass affected by drought was more obvious in this period than that from tasseling to milk-ripe stage.