生物质种类和添加量对肥液灌溉土壤入渗特征和养分运移的影响

目的 探究添加不同生物质和添加量对肥液灌溉土壤入渗特征与养分运移的影响，为提升肥液灌溉效率提供理论依据。方法 以生物炭(BC)、咖啡渣(CF)和甘蔗渣(SC)作为生物质添加材料，设置4个添加量(质量分数)水平T₁(0.5%)、T₂(1.0%)、T₃(1.5%)、T₄(2.0%)。测量肥液在不同生物质添加土壤中的运移特征及养分分布，评估不同生物质添加对土壤结构的影响。结果 3种生物质对湿润锋运移与土壤累积入渗量抑制效果均表现为SC>CF>BC，各处理组内抑制效果随生物质添加量增加有所提升；和CK组相比, SCT₄、CFT₄和BCT₄组湿润锋运移距离分别降低了38.33%、37.00%和34.00%；SCT₄、CFT₄和BCT₄组土壤累积入渗量分别降低了31.01%、30.00%和26.60%。和CK组相比，肥液灌溉下3种生物质添加均能提升土壤中3种主要无机养分，且随生物质添加量增加土壤肥力提升；3种生物质对土壤硝态氮截留总体表现为BC>CF>SC，其中，BCT₄、CFT₄和SCT₄组的土壤硝态氮含量分别提升了74.32%、56.00%和51.00%；3种生物质对土壤速效磷截留总体表现为CF>SC>BC，其中，CFT₄、SCT₄和BCT₄组的土壤速效磷含量分别提升了140.70%、139.20%和30.25%；3种生物质对土壤速效钾截留总体表现为CF>BC>SC，其中，CFT₄、BCT₄和SCT₄组的土壤速效钾含量分别提升了143.87%、126.85%和104.03%。结论 3种生物质对肥液入渗均有抑制效果，其中，生物炭效果最佳；3种生物质对肥力均有截留效果，生物炭对硝态氮截留效果最佳，咖啡渣对速效磷与速效钾截留效果最佳。

Effects of biomass types and additions on soil infiltration characteristics and nutrient transport in fertilizer irrigation

Objective In order to explore the effects of different biomass additions and amounts on soil infiltration characteristics and nutrient transport in fertilizer irrigation, so as to provide a theoretical basis for improving fertilizer irrigation efficiency. Method Biochar (BC), coffee grounds (CF) and bagasse (SC) were used as biomass additives, and four levels of addition were set including T₁ (0.5%), T₂ (1.0%), T₃ (1.5%), and T₄ (2.0%). The transport characteristics of fertilizer solution in different biomass-added soils and their nutrient distributions were measured. The effects of different biomass additions on soil structure were evaluated.Result The inhibitory effects of three kinds of biomass on wetting front migration and soil cumulative infiltration were SC>CF>BC, and the inhibitory effects in each treatment group increased with increasing biomass addition. Compared with the CK group, the wetting front migration distances of SCT₄, CFT₄ and BCT₄ decreased by 38.33%, 37.00% and 34.00% respectively. The cumulative soil infiltration amounts of SCT₄, CFT₄ and BCT₄ decreased by 31.01%, 30.00% and 26.60% respectively. Compared with the CK group, the three kinds of biomass additions under the fertilizer irrigation improved the contents of three main inorganic nutrients in soil, and the soil fertility was improved with increasing biomass addition. The overall performance of soil nitrate nitrogen retention by the three kinds of biomass was BC>CF>SC. Among them, the soil nitrate nitrogen contents of BCT₄, CFT₄ and SCT₄ increased by 74.32%, 56.00% and 51.00% respectively. The overall performance of soil available phosphorus retention by the three kinds of biomass was CF>SC>BC. Among them, the soil available phosphorus contents of CFT₄, SCT₄ and BCT₄ increased by 140.70%, 139.20% and 30.25% respectively. The overall performance of soil available potassium retention by the three kinds of biomass was CF>BC>SC. Among them, CFT₄, BCT₄ and SCT₄ increased the soil available potassium contents by 143.87%, 126.85% and 104.03% respectively.Conclusion All three kinds of biomass have inhibitory effects on the infiltration of fertilizer solution with biochar being the best. The three kinds of biomass all have interception effects on fertility, meanwhile, biochar has the best interception effect on nitrate nitrogen, and coffee grounds have the best interception effect on available phosphorus and available potassium.