| Recently,global warming has been focused by more and more people,which caused changes in soil moisture content,soil temperature,and soil nutrient storage status,then affected on crop growth,yield and quality.The addition of biochar can effectively improve physical and chemical properties of soil and mitigate greenhouse gas emissions.It is of great significance to study the effects of biochar addition on wheat growth and soil physicochemical properties,under global warming.In this study,an open top chamber(OTC)was used to simulate warming(CK,T1,T2 and T3)and apply biochar(BC0 and BC2).The samples of plant and soil were collected during the wheat growing period(three-leaf stage,tillering stage,jointing stage,flowering stage,mature stage).The objective of this study is that warming and biochar addition effect on wheat growth and soil physicochemical properties,then provide a theoretical basis for farmland management in the context of climate warming.The main results were as follows:1.The temperature increase of T1,T2 and T3 increased by 0.44,0.55 and 0.73 oC compared with CK,but the soil water content in wheat growth period was decreased by 4.8-16.9%,at three-leaf stage,jointing stag-mature stage.At the same temperature,biochar added increased soil moisture by 2.2-13.2%.2.Under warming,the soil pH values of each treatment decreased by 0.01-0.28 compared with the control during the wheat growth.Biochar had no significant effect on the soil pH value.The warming increased the available nitrogen content by 1.05-7.78mg/kg in comparison with the control at each growth stage and increased the soil phosphorus content by 6.1-161.8%.The soil organic matter and available potassium content increased first and then decreased with the rising temperature.Biochar reduced the available nitrogen content in soil and increased the content of soil organic matter,available phosphorus,and available potassium.Biochar increased soil organic matter content by 1.74-2.40 times.3.Warming decreased the activities of soil urease,sucrose and phosphatase by 2.9%-60.1%,3.0%-64.0%,and 2.74%-42.13%,respectively,at P1,P2,P3,P4.Biochar inhibited the activities of soil urease,sucrose and phosphatase at each wheat growth period.The correlation analysis of soil nutrients and soil enzyme activities found that the soil water content was significantly negatively correlated with urease and invertase activity.The grey correlation analysis showed that pH was the main factor affecting soil enzyme activity,followed by soil water content.4.The wheat phenology of T3 was 1 day earlier than the control at P2 under warming and the combination of warming and biochar.The wheat phenology of T2-BC0,T2-BC2,and T3 were ahead by 1day at P3,respectively.The wheat phenology of each treatment was advanced 1-4 days at P4 and P5.5.Warming up and biochar addition increased the plant height of wheat at each growth stage.Among them,the plant height of wheat under biochar treatment increased by 6.8%,17.4%,6.7%,18.4% and 13.6%,respectively.The treatment of Warming and biochar increased wheat biomass at P1,P2,P3,P4.However,there had no significant effect wheat biomass and yield at P5.Under the combination of warming and biochar treatment,the biomass of T1 and T2 were increased at P1,P2,P3,P4 but biomass of T3 treatment were decreased.The biomass and yield of wheat decreased at P5.6.The warming caused the N,P and K contents of wheat plants to increase first and then decrease with increasing temperature.Biochar addition increased the N,K content of wheat plants and reduced the P content.Under the combined effects of warming and biochar,the N,P,and K contents of wheat plants at different growth stages and organs showed different patterns.Through path analysis of wheat biomass and soil nutrient indexes,it was concluded that soil available phosphorus content has the largest direct coefficient of influence on wheat biomass and nutrient content in the plant,followed by soil water content.It indicated that the warming and biochar advanced wheat phenology,then decreased yield and biomass of wheat.However,it could promote the absorption of some nutrients(P,K). |
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