生物炭与沼液配施对黑土土壤养分和大豆生长的影响

Impact of Combined Application of Biochar and Digestate on Black Soil Nutrients and Soybean Growth

摘要:

提升土壤养分利用效率和生产力是推动黑土地保护和农业绿色发展的重要途径。本研究通过盆栽试验探究不同生物炭施加深度配施沼液对黑土土壤养分分布及大豆生长的影响,共设置3个生物炭施加深度：未施加（H0）、浅施于0~20 cm（H1）、深施于0~40 cm（H2）,以及常规施肥（N0）和施加沼液（N3）2种施肥方式,共6个处理。试验结果表明：深施生物炭能显著提高土壤养分含量,促进大豆生长,同时随着生物炭施加深度增加,施加沼液能进一步促进土壤养分积累和大豆生长。与H0N0相比,整个生育期内,0~20 cm土层中,H1N3处理铵态氮和硝态氮含量分别提高26.14%和30.73%,土壤微生物量氮和全氮含量分别提高18.82%和13.21%;20~40 cm土层中,H2N3处理铵态氮和硝态氮含量分别提高25.85%和33.38%,土壤微生物量氮和全氮含量分别提高20.58%和12.21%。同时,H2N3处理显著改善大豆叶片生理特性,叶绿素含量、净光合速率、气孔导度和瞬时水分利用效率分别提高39.89%、32.45%、27.01%和19.88%,大豆产量提高28.67%。基于熵权TOPSIS模型的综合评价结果表明,H2N3处理综合效益最佳,既能有效活化深层土壤资源、扩容土壤养分库,又能显著提升沼液养分利用效率,实现土壤肥力与作物产量的协同提升,为黑土区生物炭与沼液深施还田模式优化提供了科学依据。

Abstract:

Enhancing soil nutrient utilization efficiency and productivity is a crucial approach for promoting black soil conservation and sustainable agricultural development. The effects of digestate combined with biochar incorporated at different depths on black soil nutrients and soybean growth were investigated through a pot experiment. The experiment included three biochar incorporation depths: no application (H0),applied shallowly in the 0~20 cm soil layer (H1),and applied deeply in the 0~40 cm soil layer (H2),combined with two fertilization methods: conventional fertilization (N0) and digestate application (N3),resulting in a total of six treatments. The results demonstrated that deep biochar application significantly increased soil nutrient content and promoted soybean growth. Furthermore,the advantages of digestate application over conventional fertilization in enhancing soil nutrient accumulation and soybean growth became more pronounced with increasing biochar incorporation depth. Throughout the growth period,compared with the H0N0 treatment,in the 0~20 cm soil layer,the H1N3 treatment increased ammonium nitrogen and nitrate nitrogen content by 26.14% and 30.73%,respectively,soil microbial biomass nitrogen by 18.82%,and total soil nitrogen by 13.21%. In the 20~40 cm soil layer,the H2N3 treatment increased ammonium nitrogen and nitrate nitrogen content by 25.85% and 33.38%,respectively,soil microbial biomass nitrogen by 20.58%,and total soil nitrogen by 12.21%. Additionally,the H2N3 treatment significantly enhanced soybean physiological parameters: leaf chlorophyll content was increased by 39.89%,net photosynthetic rate was increased by 32.45%,stomatal conductance was increased by 27.01%,and instantaneous leaf water use efficiency was increased by 19.88%. Correspondingly,soybean yield was increased by 28.67%. A comprehensive evaluation based on the entropy-weighted TOPSIS model identified the H2N3 treatment as the most effective. This treatment not only effectively activated deep soil resources and expanded the soil nutrient pool but also significantly improved the nutrient use efficiency of digestate,resulting in a notable synergistic enhancement effect on both soil fertility and crop yield. These findings can provide a scientific basis for optimizing the deep application of biochar and digestate in black soil regions.