生物炭对碱性砂质土壤小麦出苗及幼苗生长的影响

为探究生物炭还田对砂质土壤小麦出苗和幼苗生长的影响及原因。本研究设置2个盆栽试验。试验1比较0%、0.6%、1.8%、3.6%和5.4%(质量分数)5个生物炭梯度对小麦出苗率、小麦萎蔫时含水量和有效水含量的影响。结果表明,随生物炭施用量的增加出苗率及有效水含量呈降低趋势,小麦萎蔫时含水量则与之相反。在此基础上,试验2进一步研究30%~50%(WL)、50%~70%(WF)、70%(WE)3个水分梯度下生物炭施用量与5个生物炭梯度的耦合效应试验,分析其对幼苗生长、土壤pH和EC的影响。结果表明,各水分梯度下施用过量生物炭(3.6%)抑制小麦幼苗生长,WF和WE水分条件下土壤pH和WL、WF和WE水分条件下土壤电导率均与小麦根系活力、植株含水量和地上部生物量显著负相关。综合表明,在碱性土壤中施用生物炭后会提高土壤pH和EC,从而抑制小麦出苗和幼苗生长。

Effect of biochar amendment on wheat emergence and seedling growth in alkaline soil

To investigate the influences and mechanism of biochar amendment on wheat emergence and seedling growth in alkaline soil,two experiments were conducted in Wuqiao experiment station of China Agricultural University.The effects of different biochar application rates (0,0.6%,1.8%,3.6% and 5.4%) on wheat emergence rate,soil water content of wheat wilting and soil available water were investigated in the first experiment.The results showed that biochar inhibited the emergence of wheat.With the increase of application rates,the emergence rate and soil available water decreased while soil water content of wheat wilting increased.The effects of biochar application on seedling growth,soil pH and EC were studied under three water levels of 30%-50% (WL),50%-70% (WF) and >70% (WE) in the second experiment.The results showed that excessive application of biochar (>3.6%) inhibited the growth of wheat seedlings under all water levels.Soil pH under WF and WE water levels,soli EC under all water levels were negatively correlated with root activity,plant water content and aboveground biomass.It was found that the application of biochar in alkaline soil increased the soil pH and EC,and thus inhibited the emergence and seedling growth of wheat.