生物炭陈化对玉米产量及土壤水肥的影响

Effects of biochar aging on yield of maize and soil moisture and fertility

为探究生物炭陈化对农田土壤水肥的作用效果,设置2种陈化时间的生物炭Y_(1)、Y_(5)(新施入土壤的生物炭、田间自然陈化第5年的生物炭)和3个生物炭施用量C_(0)、C_(6)和C_(12)(0、6和12 t·hm^(-2))的田间双因素随机区组试验,研究生物炭陈化对玉米产量、不同土层含水率和土壤肥力的影响。结果表明:相同施炭量下,陈化第5年的生物炭较新鲜生物炭对玉米产量及土壤水肥效应所表现出的正向效应均降低。Y_(1)C_(12)处理玉米产量提升最高(28.3%),Y_(5)C_(6)处理玉米产量提升最低(6.9%);相同施炭量下,陈化第5年生物炭的玉米增产效应小于新鲜生物炭。除Y_(5)C_(6)处理外,其余生物炭处理与Y_(1)C_(0)(Y_(5)C_(0))处理相比均显著提高了玉米的水分利用效率(P<0.05),提升幅度为5.4%~16.7%。施用生物炭对土壤含水率的影响主要集中在表层土壤,陈化生物炭处理的土壤含水率较新鲜生物炭处理的土壤含水率显著降低,5年低量生物炭Y_(5)C_(6)处理下的土壤含水率与Y_(1)C_(0)(Y_(5)C_(0))处理无显著差异。施用生物炭显著增加了土壤硝态氮、铵态氮、碱解氮、全氮、有效磷、速效钾含量,进而提升土壤综合肥力,但陈化第5年的生物炭对土壤养分提升效果低于新鲜生物炭,各处理土壤综合肥力表现为Y_(1)C_(12)>Y_(5)C_(12)>Y_(1)C_(6)>Y_(5)C_(6)>Y_(1)C_(0)(Y_(5)C_(0))。本研究结果可为合理利用生物炭提供科学依据。

To explore the effects of biochar aging on soil moisture and fertility in cropland,we set up a field two-factor randomized block experiment.There were two kinds of biochar with different aging time(newly applied biochar to the soil,Y_(1);biochar for the 5 th year of natural aging in the field,Y_(5)) along with three doses of biochar application(0 t·hm^(-2),C_(0);6 t·hm^(-2),C_(6);12 t·hm^(-2),C_(12)).We investigated the effects of those two different types of biochar on maize yield,water content and fertility in different soil layers.Results showed that under the same dose of biochar application,the positive effects of biochar with the 5 th year of aging on maize yield,soil moisture and fertility were lower than that of fresh biochar addition.The maximum increment(28.3%) of maize yield was observed under Y_(1)C_(12) and the minimum increment(6.9%) under Y_(5)C_(6).The positive effect of biochar in the 5 th year of aging on yield was less than that of fresh biochar under the same application dose.Except the Y_(5)C_(6) treatment,biochar addition significantly improved water use efficiency of maize compared with the Y_(1)C_(0)(Y_(5)C_(0)) treatment(5.4%-16.7%).The effect of biochar application on soil moisture was mainly concentrated in the surface soil.The soil moisture under the aged biochar treatment was significantly lower than that of the fresh biochar treatments.There was no significant difference in soil moisture between the treatment of aged biochar with low dose(Y_(5)C_(6)) and the treatment of Y_(1)C_(0)(Y_(5)C_(0)).The application of biochar significantly increased the contents of soil nitrate,ammonium,alkaline hydrolysis nitrogen,total nitrogen,available phosphorus,and available potassium,and thus improved the comprehensive soil fertility,and such effects of biochar in the 5 th year of aging on soil nutrients were lower than that of fresh biochar.The comprehensive soil fertility of various treatments was in order of Y_(1)C_(12)>Y_(5)C_(12)>Y_(1)C_(6)>Y_(5)C_(6)>Y_(1)C_(0)(Y_(5)C_(0)).Our results can provide theoretical foundation for rational utilization of biochar.