生物炭与土壤调理剂对滨海荒芜重盐碱地的改良效应

Effects of Biochar and Soil Conditioner on Coastal Barren Saline-alkali Soil

以土壤改良剂对荒芜重盐碱地生物改良和开发利用为研究目标,在华北低平原区滨海荒芜重盐碱地开展了施用生物炭(B)和调理剂(C)种植先锋作物油葵的大田试验.生物炭用量设2个水平(0和1.25 kg·m^(-2))调理剂施用量设3个水平,分别为0、0.83和1.66 kg·m^(-2),共6个处理.油葵收获后按照每30 cm一层采至90 cm搜集土样.结果表明,施用生物炭提高0~30 cm和60~90 cm土层含盐量,而土壤调理剂则显著降低0~30 cm土壤含盐量.没有发现生物炭或调理剂对土壤pH有显著影响.生物炭处理显著抑制土壤硝化作用,导致0~90 cm土层NO_(3)^(-)-N含量显著下降,NH_(4)^(+)-N含量提高,对有机质(SOM)含量没有显著影响.施用土壤调理剂提高0~30 cm土壤SOM含量,调理剂施用量为1.66 kg·m^(-2)时0~90 cm土层的NO_(3)^(-)-N含量显著增加.单施生物炭与调理剂或者二者组合均显著增加0~90 cm土壤NH_(4)^(+)-N含量、有效磷(Olsen-P)含量和有效钾(K_(ex))含量,但生物炭对这3种养分含量的提升效果更显著,土壤调理剂则在增加0~30 cm土壤有机质和降盐方面更有效.施用高量调理剂促进土壤硝化作用,而施用生物炭恰恰起到硝化抑制剂的作用,因此,将生物炭与土壤调理剂结合施用,是滨海荒芜重盐碱地防止NO_(3)^(-)-N淋失、减少环境污染、增肥降盐并保障耐盐先锋作物高肥低盐生长环境的有效措施.

This study aimed to quantify the biological improvement and availability from a soil amendment substance for barren severe saline-alkali soils.A field experiment was conducted to apply biochar(B)and soil conditioner(C)rich in humic substances to pioneer crops and oil sunflower planted in the coastal barren severe saline-alkali area of the North China Low Plain.The six treatments included single or combined application of two-level biochar rates(0 and 1.25 kg·m^(-2))and three-level soil conditioner rates(0,0.83,and 1.66 kg·m^(-2))at the start of the experiment.Soil samples were collected at 30 cm per layer and sampling from 0 to 90 cm after the oil was collected.The results revealed that the application of biochar increased the saline concentration of the 0-30 cm and 60-90 cm soil layers,whereas the soil conditioner significantly decreased the saline concentration of the 0-30 cm soil layers.Neither biochar nor conditioner showed a significant impact on soil pH.Biochar exhibited varying impacts on soil nutrients,that is,significantly inhibiting soil nitrification,which resulted in soil NO_(3)^(-)-N decreasing while NH_(4)^(+)-N increased significantly,along with no significant impact on soil organic matter content(SOM)in the 0-90 cm soil profile.The application of soil conditioner exerted positive effects on improving SOM in the 0-30 cm layer and NO_(3)^(-)-N in the 0-90 cm soil depth when the conditioner rate was at 1.66 kg·m^(-2).Either the sole application or the co-application of biomass and conditioner,along with their interaction,exhibited an increasing trend for the NH_(4)^(+)-N,available phosphorus(Olsen-P),and available potassium(K_(ex))contents,also seen in the 0-90 cm soil profile,although the increase effect for the three nutrients was primarily attributed to biochar.Soil conditioner was more effective in increasing SOM and reducing saline in the 0-30 cm soil layer.The application of a higher amount of conditioner accelerated soil nitrification,whereas biochar was applied essentially as a nitrification inhibitor.Therefore,the co-application of biochar with soil conditioner would be an effective practice for improving soil fertility,preventing soil nitrification,and deterring nitrate leaching,as well as reducing saline for topsoil,which would be a basis for developing soil amendments to control saline and a fertile soil environment for pioneer crops planted in coastal barren severe saline-alkali areas.