保护性耕作介导的水热变化对东北玉米高产稳产性的可能影响

Possible effects of conservation tillage on yield level and its stability of spring maize in Northeast China

关键词:  保护性耕作  玉米  产量

Key words:  conservation tillage  maize  yield

摘要:

【目的】 全球气候变化背景下，我国东北地区主要呈现气候暖干化趋势，而保护性耕作是农业应对气候变化的重要措施。探究4种主要保护性耕作措施（秸秆覆盖、免耕、免耕+秸秆覆盖和深松）介导的农田水热变化对东北玉米高产稳产性的可能影响，可为区域尺度上推广应用保护性耕作提供科学参考。【方法】 文章以保护性耕作介导下玉米生长季内的土壤水热变化为切入点，应用APSIM-Maize模型评估1988—2017年保护性耕作对东北玉米高产性稳产性的可能影响。【结果】 （1）与传统耕作相比，保护性耕作措施下黑龙江和吉林两地的玉米单产分别减少262 kg/hm²和119 kg/hm²，产量变异系数分别下降0.03和0.06，辽宁和内蒙古东四盟的玉米单产分别增加452 kg/hm²和2 458 kg/hm²，产量变异系数分别下降0.08和0.25；各研究站点单产呈东减西增、增产大于减产，产量变异系数呈降幅普遍大于增幅，整体下降的变化趋势；最高稳区和高稳区占研究区域面积的比例由45.63%降低为37.41%，单产分别降低64 kg/hm²、57 kg/hm²，可应用区占研究区域面积的比例由27.16%降低为18.84%，单产增加515 kg/hm²，而次高稳区面积占比由27.21%增加为43.76%，单产增加860 kg/hm²。（2）与传统耕作相比，4种保护性耕作措施下东北地区玉米整体呈增产，同时产量变异系数均出现下降；最高稳区和可应用区面积均缩小，次高稳区面积均扩大，高稳区面积在免耕+秸秆覆盖和深松措施下扩大，在秸秆覆盖和免耕措施下缩小。【结论】 东北玉米农田采取保护性耕作措施后黑龙江和吉林减产较少，辽宁和内蒙古东四盟大幅增产，同时产量变异系数均有不同程度下降，因此应用保护性耕作措施后东北地区整体高产性和稳产性提高。黑龙江可采取深松措施，吉林推广秸秆覆盖和免耕+秸秆覆盖均有良好增产稳产效果，而辽宁和内蒙古东四盟在4种保护性耕作措施下均表现出较传统耕作更优的高产稳产性，宜根据当地环境实施合适的保护性耕作措施。

Abstract:

Purpose Under the background of global climate change，Northeast China mainly presents the trend of climate warming and drying，and conservation tillage is an important adaptation measure for agriculture to climate change. Exploring the possible effects of four major conservation tillage measures（straw mulching，no-tillage，no-tillage + straw mulching，and subsoiling）on the high and stable yield of maize in Northeast China can provide a scientific reference for the promotion and application of conservation tillage at the regional scale.Method In this study，using the changes of soil temperature and humidity during the growing season mediated by conservation tillage as the starting point，the APSIM-Maize model was used to evaluate the possible effects of conservation tillage on the yield level and its stability of maize in Northeast China from 1988 to 2017.Result Compared with conventional tillage，the maize yield in Heilongjiang and Jilin under conservation tillage decreased by 262 kg/hm² and 119 kg/hm²，respectively，and the yield variation coefficient decreased by 0.03 and 0.06，respectively. The maize yield in Liaoning and Inner Mongolia increased by 452 kg/hm² and 2 458 kg/hm²，respectively，and the yield variation coefficient decreased by 0.08 and 0.25，respectively. The yield of each research site decreased in the east and increased in the west，and the increase was greater than the decrease. The coefficient of variation of yield decreased more than the increase，and the overall trend was downward. The proportion of the highest stable area and the high stable area in the study area decreased from 45.63% to 37.41%，and the yield per unit area decreased by 64 kg/hm² and 57 kg/hm²，respectively. The proportion of the applicable area in the study area decreased from 27.16% to 18.84%，and the yield per unit area increased by 515 kg/hm²，while the proportion of the sub-high stable area increased from 27.21% to 43.76%，and the yield per unit area increased by 860 kg/hm². Compared with conventional tillage，the overall yield of maize in Northeast China increased under the four conservation tillage measures，and the coefficient of variation of yield decreased. The area of the highest stable area and the applicable area decreased，and the area of the sub-high stable area increased. The area of the high stable area increased under "no-tillage and straw mulching" and subsoiling measures，and decreased under straw mulching and no-tillage measures.Conclusion Under conservation tillage，the maize yield in Liaoning and Inner Mongolia increase significantly. At the same time，the coefficient of variation of yield decreases. Therefore，the overall yield level and stability of Northeast China increases under the conservation tillages. In Heilongjiang province，subsoiling measures can be adopted，and in Jilin province，straw mulching and "no-tillage and straw mulching" have good effect of increasing and stabilizing yield，while Liaoning and Inner Mongolia have higher and more stable yield than traditional tillage under the four conservation tillage measures，and appropriate conservation tillage measures should be implemented according to the local environment.