Effects Of Different Biomass Mulching On Growth Characteristics And Nitrogen Utilization Rate Of Summer Maize

In order to effectively explore the effects of different mulching methods on crop physiological and ecological indicators,plant nitrogen accumulation and nitrogen utilization rate,this study was conducted in2017-2018.In the course of the experiment,three mulching modes were setup:biochar regulation（M1）,combined regulation of biochar and straw（M2）,straw regulation（M3）.At the same time,each mulching mode is set three gradient levels:6t?hm^-2（F1）,12t?hm^-2（F2）,18t?hm^-2（F3）and control group（CK）.There is a total of ten treatments.The main conclusions are as follows:（1）Biomass mulching can reduce soil temperature at high temperature and maintain soil temperature at low temperature.Among them,the combined regulation of biochar and straw（M2）has significant cooling and heat preservation effects.The effect of biochar regulation（M1）was the second,and that of straw regulation（M3）was the worst.（2）Biomass mulching significantly increased soil moisture content.Among them,the combined regulation of biochar and straw（M2）has significant cooling and heat preservation effects.The effect of biochar regulation（M1）was the second,and that of straw regulation（M3）was the worst.（3）Biomass mulching significantly increased the content of soil inorganic nitrogen.Among them,the combined regulation of biochar and straw（M2）has the most significant effect on improving the content of inorganic nitrogen in soil.With the increase of coverage,the content of inorganic nitrogen in soil increased.However,the content of ¹⁵N%in the soil decreased,and the consumption of fertilizer nitrogen increased.（4）Different mulching treatments had significant effects on plant height,leaf area and dry matter accumulation of summer maize,and had significant yield increasing benefits.Among them,the combination of biochar and straw（M2）treatment has the most significant effect.Compared with other mulching methods,the average plant height of maize increased by 4.53%～7.82%.The average leaf area index increased by 4.30%～16.12%.Dry matter accumulation increased by 12.41%～30.13%.The average yield increased by 6.96%～20.33%.（5）Different mulching treatments effectively improved the nitrogen accumulation effect of plants.With the increase of coverage,the nitrogen content from nitrogen increased significantly.As shown by the analysis of the adsorption of marked nitrogen by each organ,the results of ¹⁵N use efficiency in organs,ranked in descending order,were as follows:grain>stem+leaf sheath>root>blade>loquat leaf+cob.（6）It is found through Pearson and related analysis that the biochar（M1）regulation effect effectively promoted the adsorption of marked nitrogen fertilizer by root system,the combined regulation of biochar and straw（M2）facilitated the regulating effect of grain on marked nitrogen fertilizer and straw（M3）boosted the accumulation of marked nitrogen fertilizer in stalk+sheath.