基于决策系统模拟不同降水年型旱作冬小麦的最佳播期

Analysis on the Optimal Sowing Date of Dry-land Winter Wheat under Different Precipitation Pattern Based on Wheat Decision System

冬前积温以及播前土壤墒情是旱作冬麦区播期选择的重要依据,利用模型选择不同降水年型下小麦适宜播期具有重要意义。收集山西省闻喜县旱作小麦区2009-2014年(2009、2010和2012年为枯水年,2011年和2013年为丰水年)的大田试验数据,对小麦决策系统进行品种参数校验和验证。利用校验过的决策系统模拟分析闻喜地区近36a(1980-2015年)冬小麦最佳播期变化以及不同降水年型下播期随产量的变化情况。结果表明:(1)1980-1984年,冬小麦最佳播期主要集中在9月25日前后;1985-1995年,历史最佳播期推迟至9月30日前后;1995-2015年,最佳播期推迟至10月5日前后。(2)研究期内,丰水年和平水年9月30日前后播种小麦平均产量最大,分别为4293.1kg·hm^(-2)和4055.2kg·hm^(-2);枯水年10月5日前后播种小麦平均产量最高,为3334.5kg·hm^(-2)。因此,随着气温的逐渐增高,冬小麦的历史最佳播期呈现明显后移趋势;丰水年和平水年9月30日前后播种,枯水年以10月5日前后播种为宜。

Thermal time before winter and soil moisture before sowing are the important basis for the selection of sowing date in dry-land wheat area.It is of great significance to use the decision system to select the optimal sowing date of wheat under different precipitation years.The wheat decision system was calibrated and validated by using field test data of winter wheat in Wenxi county of Shanxi province from 2009 to 2014 years(2009,2010 and 2012 were dry year,2011 and 2013 were wet year).The modified decision system was used to simulate and analyze the change of the optimal sowing date of winter wheat and the change of sowing date with yield under different precipitation years in recent 36 years(1980-2015)in Wenxi area.The results showed that,(1)the optimal sowing date was mainly around September 25 in 1980-1984,the optimal sowing date was around September 30 in 1985-1995,the optimal sowing date was around October 5 in 1995-2015.(2)The average yield of wheat reached the highest value when sown around September 30 in wet year and normal year,which were 4293.1kg·ha^(-1) and 4055.2kg·ha^(-1),respectively;the average yield of wheat reached the highest value(3334.5kg·ha^(-1))when sown around October 5 in dry year.Therefore,with the increase of atmospheric temperature,the historical optimal sowing date of winter wheat was delaying;it was appropriate to sow around September 30 in wet year and normal year,and around October 5 in dry year.