播期和播深对冬小麦越冬前生长性状的影响

Effects of Sowing Date and Sowing Depth on Winter Wheat Growth before Overwintering

为评价播期和播深对冬小麦越冬前生长性状的影响,以农大211冬小麦为试验材料,于2015—2017年在中国农业大学北京上庄实验站进行了4个播期水平(9月23日、10月3日、10月13日和10月23日)、3个播深水平(2、4、6 cm)的随机区组大田试验,探究不同栽培措施对越冬前冬小麦各生长指标(单株叶面积、主茎叶龄、分蘖数、地上部干物质量、分蘖节入土深度、地中茎长度和株高)的影响。并于2016年和2018年开展梯度播种试验,设置不同播期(2016年9月23日、10月3日、10月13日和2018年10月23日、11月3日),对分蘖节入土深度进行定量化模拟。结果表明:随着播期推迟,单株叶面积、主茎叶龄、分蘖数和地上部干物质量均显著减少(P<0.05),地中茎长度和株高随着播种深度的增加逐渐增加。播期、播深、播期与播深的交互效应均对冬小麦分蘖节入土深度有显著影响,冬小麦分蘖节入土深度与越冬前积温为负相关的线性关系,随着播期推迟分蘖节入土深度逐渐增加,冬小麦分蘖节入土深度和播深呈对数曲线规律。依据梯度播种试验数据进行分蘖节入土深度的模拟,建立了分蘖节入土深度与越冬前有效积温和播种深度的定量关系。研究结果对于评价冬小麦地上地下部性状、制定防冻保苗措施具有重要意义。

The climate change will lead to tremendous environmental risk.As a common agrometeorological disaster of winter wheat,the frequency and loss of low temperature and freezing injury are also significantly increased.In order to study the effect of different cultivation measurements on morphological indexes of winter wheat before overwintering,including leaf area per plant,main stem leaf age,tillering number,aboveground biomass,tillering node depth,stem length in the ground and plant height,the randomized block field trials with seven sowing dates(Oct 3,Oct 13,Oct 23 in 2015,and Sep 23,Oct 3,Oct 13,Oct 23 in 2016)and three horizontal seeding depths(2 cm,4 cm and 6 cm)were carried out during 2015—2017,using‘Nongda211’as object at the Shangzhuang Experimental Station of China Agricultural University in Beijing.The gradient deep-sowing experiment with different sowing dates(Sep 23,2016,Oct 3,2016,Oct 13,2016,and Oct 23,2018,Nov 3,2018)was further carried out to quantitatively simulate the depth of tillering node.The results of field experiment on sowing date and sowing depth showed that with the delaying sowing date,the leaf area,leaf age of main stem,tiller number of single plant and aboveground biomass of winter wheat were decreased significantly.With the deepening of sowing depth,the depth of tillering node,stem length in the ground and the height of plant were increased gradually.The sowing date,sowing depth and the interactive effects of sowing date and sowing depth all had significant impact on the tillering node depth of winter wheat.There was a linear relationship between the tillering node depth of winter wheat and the accumulated temperature before overwintering.As the sowing date was delayed,the tillering node depth was gradually increased.And the winter wheat tillering node depth and sowing depth showed a logarithmic curve.The tillering node depth was increased with the increase of depth of sowing.The quantitative relationship between the soil depth of tiller node and the effective accumulated temperature before winter was established with the experiment data of gradient seeding depth at different sowing dates.The results could provide a reference model for further study of freezing damage.