生物炭添加对降低盐滩地有害离子及促进玉米生长效果研究

Effect of Supplement of Biochar in Saline Land on Reducing Harmful Ions and Promoting Maize Growth

黄河三角洲盐渍化土壤改良是农作物产量提升的主要途径之一。为了解生物炭施用对降低盐滩地有害盐分离子浓度和促进玉米生长效果的影响,通过田间试验,研究秸秆还田、秸秆还田加化肥施用和不同类型低剂量(3 g·kg^(-1))生物炭(棉秆炭、芦苇炭和玉米芯生物炭)添加对盐渍土有害盐离子、电导率、钠吸附比对玉米生长效果的影响。结果表明,生物炭的添加可降低土壤溶液中有害盐分离子浓度、电导率、钠吸附比(SAR),提升玉米地下和地上生物量。以芦苇炭施用(3 g·kg^(-1))降盐效果最为明显,土壤溶液中Na^(+)浓度较对照降低了76%,土壤电导率降低了33%,土壤钠吸附比(SAR)降低了52%。以玉米芯生物炭施用(3 g·kg^(-1))对降低土壤钠吸附比和电导率最为显著,分别较对照降低了58%和45%,土壤溶液中Na^(+)浓度较对照降低了47%,并且玉米芯生物炭施用对提升玉米地上和地下生物量显著,分别较秸秆还田增加了12.19倍和6.78倍。生物炭添加可以降低土壤溶液中的Na^(+)、钠吸附比和电导率,提升K^(+)浓度缓解盐的胁迫,提高玉米的耐盐性进而提升玉米的生物量。

In the Yellow River Delta region,improvement of salinized soil is one of the main ways to increase crop yield. In order to understand the effect of biochar application on reducing the level of harmful salt ions and promoting the growth of maize,we applied different types of low-dose(3 g·kg^(-1))biochar(cotton straw charcoal,reed charcoal and corncob biochar)to the soil,compared with the straw returning and straw returning combined with chemical fertilizer applying, to measure the level of harmful ions, electrical conductivity,sodium adsorption ratio of soil and growth of maize. The results showed that the supplement of the biochar significantly reduced the concentration of harmful ions,electrical conductivity,sodium adsorption ratio of soil and above-and below-ground biomass of the maize;the most effective biochar of salt reduction was reed charcoal carbon(3 g·kg^(-1)),with which the Naconcentration in soil solution was decreased by 76%,compared with the control and corncob biochar(47%);however,the corncob biochar(3 g·kg^(-1))was the more effective for reducing the soil sodium adsorption ratio(SAR)and electrical conductivity than that of the control and reed biochar(52% and 33% respectively),which decreased by 58% and 45% respectively. Moreover,the application of corncob biochar was the most effective for increasing above-and below-ground biomass of the maize,by 12. 19 and 6. 78 respectively compared with the straw returning. Conclusively,supplement of biochar can significantly reduce Na^(+) concentration,SAR and conductivity,increase K^(+) concentration,alleviate salt stress,improve salt tolerance of maize,and increase biomass of it. The results provided theoretical basis for reducing salt damage,improving soil quality and increasing crop yield,and would provide preliminary guidance for the practical application of biochar in saline soil improvement.