生物炭与土壤调理剂对滨海荒芜重盐碱地的改良效应

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NO₃^--N含量显著下降，NH₄⁺-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NO₃^--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NH₄⁺-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NO₃^--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.

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

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 NO₃^--N decreasing while NH₄⁺-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 NO₃^--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 NH₄⁺-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.