秸秆生物炭对潮土区小麦产量及土壤理化性质的影响

Effects of Straw Biochar Application on Grain Yield of Wheat and Physicochemical Properties in Fluvio-aquatic Soil

为了探讨生物炭施用对华北潮土农田土壤改良及小麦增产的效果,自2011年开始,在华北小麦-玉米轮作典型潮土农田通过设置0(BC0),2.25(BC2.25),6.75(BC6.75),11.25 t/hm2(BC11.25)4个秸秆生物炭处理的田间定位试验,系统研究了施用生物炭对小麦籽粒产量、土壤含水量及土壤理化性状的影响。结果表明,短期施用生物炭对小麦籽粒产量、生物量、土壤硝态氮、有机碳和全氮含量均无显著性影响,连续施用生物炭9季后,与BCO相比,BC2.25、BC6.75、BC11.25处理小麦籽粒产量分别显著增加24.5%,8.8%,9.1%(P<0.05),小麦生物量分别显著增加18.8%,8.1%和6.1%。而且,随生物炭用量增加,土壤含水量和总孔隙度逐渐增加,容重逐渐降低,与对照相比,BC6.75和BC11.25处理土壤总孔隙度分别显著增加14.1%和26.0%(P<0.05),含水量增加34.4%和42.2%,容重降低10.7%和19.6%。此外,生物炭长期施用BC6.75和BC11.25处理土壤硝态氮、有机碳和全氮含量均显著高于其他处理,与对照相比,第9季BC6.75处理土壤耕层硝态氮含量显著增加128.7%,BC6.75和BC11.25处理有机碳含量分别显著增加127.9%和179.6%(P<0.05),全氮含量增加25.4%和30.5%,但BC6.75和BC11.25处理籽粒产量在第9季显著低于BC2.25处理。综上所述,生物炭长期连续施用能够起到降低土壤容重,增加土壤含水量和孔隙度,提高耕层硝态氮、有机碳和全氮含量,以及提高小麦籽粒产量和生物量的作用。从秸秆资源良性循环发展角度来看,研究地区适宜秸秆生物炭用量为2.25 t/hm2。

To explore response of biochar application on wheat yield,physicochemical properties and fertility in fluvio-aquatic soil in wheat and maize rotation system of Northern China,a fixed field experiment was carried out with 4 straw biochar application treatments （0,2.25,6.75,11.25 t/ha,expressed as BC0,BC2.25,BC6.75 and BC11.25）. The results showed that one crop season with biochar application had no significant effects on grain yield,biomass of wheat,nitrate nitrogen content （NO - 3-N）,soil organic carbon （SOC） and total nitrogen （TN） content. After 9 crop seasons of continuous biochar application,compared with BC0,BC2.25,BC6.75 and BC11.25 treatments increased grain yield by 24.5%,8.8% and 9.1%（ P〈 0.05）,and increased biomass by 18.8%, 8.1% and 6.1% at the P 〈0.05 level,respectively. Furthermore,soil bulk density （SBD） in topsoil decreased with the increased of the amount of biochar,but soil moisture content and total porosity was enhanced. Compared with the control,BC6.75 treatment increased soil total porosity and soil moisture content by 14.1% and 34.4%,and decreased SBD by 10.7%,respectively,and BC11.25 treatment increased soil total porosity by 26.0% and soil moisture content by 42.2%,and decreased SBD by 19.6%,respectively. After 9 crop seasons with biochar application,the content of NO - 3-N,SOC and TN in topsoil under the BC6.75 and BC11.25 treatments were significantly higher than those of BC2.25 and BC0. In the 9th season,BC6.75 treatment showed a significant increase in NO - 3-N content of 128.7%. Moreover,compared with the control,BC6.75 and BC11.25 treatments increased SOC by 127.9% and 179.6%,and increased TN by 25.4% and 30.5%,respectively. The experiment showed that the long-term continuous application of biochar decreased SBD,increased soil moisture content and total porosity,increased NO - 3-N,SOC and TN content in topsoil,and improved grain yield and biomass of wheat. However,compared with the BC2.25 treatment,the BC6.75 and BC11.25 treatments significantly decreased grain yield of wheat in 9th season. Considering the effects of long-term application of biochar on wheat yield and soil physicochemical properties,biochar application with 2.25 t/ha had a good prospect in fluvio-aquatic soil of North China Plain .