Using ʻHongnuo 16ʼ sorghum as the experimental material and under equivalent nutrient input conditions, six treatments were established: no fertilization (CK), conventional fertilization (HF), and nitrogen organic fertilizer substitution ratios for nitrogen of 25% (NF25), 50% (NF50), 75% (NF75), and 100% (NF100). The results showed that compared with CK treatment, increasing the ratio of organic fertilizer substitution led to varying degrees of improvement in soil organic matter, total nitrogen, alkaline hydrolyzed nitrogen, available phosphorus, and available potassium contents. The activities of alkaline phosphatase, urease, and sucrase in soils treated with organic manure substitutions were significantly increased by an average of 40.8%, 13.6%, and 61.6%, respectively. Sorghum yield could be well fitted with a quadratic equation, with the highest yield obtained when applying cow manure at a nitrogen rate of 92.5 kg/ha theoretically. In this experiment, the treatment NF50 not only improved soil physicochemical properties and enhanced soil enzyme activity but also maintained sorghum at high productivity. Considering the responses in terms of sorghum yield and soil fertility as well as soil enzyme activity under different levels of organic manure substitution, it was suggested that an organic nitrogen substitution ratio of 50% was suitable for optimal application rates.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |