食（药）用菌菌糠对砂壤土团聚体性状的影响

为探明不同碳氮比的食（药）用菌菌糠对土壤团聚体的作用效果，采用室内恒温培养试验研究了添加香菇菌糠、灰树花菌糠和双孢菇菌糠对砂壤土水稳性团聚体组成和性状的影响。结果表明：3种供试菌糠都能够有效增大砂壤土团聚体的平均重量直径，增加幅度香菇菌糠(206.8%)>双孢菇菌糠(81.8%)>灰树花菌糠(54.5%)，添加香菇菌糠使土壤团聚体性状评级从较差提升到了良好至优级别。香菇菌糠处理的团聚体性状都随着的添加量和培养时间显著提升，团聚体性状指标的增加主要与<0.25 mm团聚体通过团聚作用向大团聚体转化有关；灰树花菌糠处理团聚体性状指标的增加则是<0.25 mm团聚体在真菌菌丝的缠绕作用下在短时间内形成较大团聚体，新形成的团聚体稳定性较差；而双孢菇菌糠处理中，0.25~1 mm团聚体向3~5 mm较大团聚体的转化对团聚体性状指标的提升起到重要作用。不同菌糠对砂壤土团聚体性状的改善能力有着很大差异，菌糠的碳氮比是影响其对土壤团聚体性状改善效果的重要因素。菌糠碳氮比过高导致其对团聚体性状的改善作用仅具有短效机制，形成的团聚体不具有长效稳定性；而菌糠碳氮比过低则达到改善效果所需菌糠的添加量大幅增加，并且改善作用发生极其缓慢。当菌糠碳氮比在微生物活动适宜碳氮比2倍(50:1)左右时，其用于改善砂壤土团聚体的性价比较高，并且能够获得长效作用机制。

Effects of Edible (Medicinal) Fungus Residues on Aggregate Properties of Sandy Loam Soils

To find out the effects of edible (medicinal) fungus residues under different carbon-nitrogen ratios on soil aggregates, an indoor constant temperature culture experiment was used to study the effects of adding Lentinus edodes residues, Grifola frondosa residues, and Agaricus bisporus residues on the composition and properties of water-stable aggregates in sandy loam soils. The results showed that the three tested fungi residues could effectively increase the average weight diameter of sandy loam soil aggregates, and the increase range was Lentinus edodes residues (206.8%) > Agaricus bisporus residues (81.8%) > Grifola frondosa residues (54.5%), the adding of Lentinus edodes residues improved the soil aggregate property rating from good to excellent. The aggregate properties treated by Lentinus edodes residues were significantly improved with the adding amount and cultivation time, and the increase of aggregate property index was mainly related to the transform of aggregates < 0.25 mm into large aggregates through agglomeration. The increase of the aggregate property index in Grifola frondosa residues’ treatment was mainly related to the aggregates of <0.25 mm forming larger aggregates in a short time under the entanglement of the fungal mycelium, but the newly formed aggregates had poor stability. While in the treatment of Agaricus bisporus residues, the transformation of 0.25-1 mm aggregates to 3-5 mm aggregates played an important role in the improvement of aggregate property index. The ability of different edible (medicinal) fungus residues to improve the properties of sandy loam aggregates was very different, and the carbon-nitrogen ratio of fungus residues was an important factor that affecting the improvement of soil aggregate properties. Too high carbon-nitrogen ratio of the fungus residues resulted in only a short-acting mechanism for improving the properties of the aggregates, and the aggregates formed did not have long-term stability. However, if the carbon-nitrogen ratio of the fungus residues was too low, the amount of fungus residues added to achieve the improvement effect was greatly increased, and the improvement effect was very slowly. When the carbon-nitrogen ratio of fungus residues was about twice the suitable carbon-nitrogen ratio for microbial activity (50:1), it was more cost-effective for improving sandy loam aggregates, and a long-term mechanism of action could be obtained.