Zhou Hanjun, Zhang Mingjie, Yang Jiahao, Wang Jing, Chen Yulu, Ye Xiefeng
Key Laboratory of Tobacco Cultivation of Tobacco Industry, National Tobacco Cultivation & Physiology & Biochemistry Research Centre, Tobacco Science College of Henan Agricultural University, Zhengzhou, China.
College of Natural Resources and Environment, Northwest A&F University, Yangling, China.
Front Microbiol. 2023 Oct 9;14:1257924. doi: 10.3389/fmicb.2023.1257924. eCollection 2023.
The widespread and continuous cultivation of tobacco has led to soil degradation and reduced crop yields and quality. Green manure is an essential organic fertilizer that alleviates obstacles to continuous cultivation. However, the plant-soil microecological effects of green manure on flue-cured tobacco cultivation remain unclear. Thus, a positioning trail including two treatments, chemical fertilizer application only (treatment NPK) and chemical fertilizer application with turning ryegrass (treatment NPKG) was conducted, and the effect of ryegrass returning on the soil physicochemical properties, soil microbiome, crop yield, and quality of flue-cured tobacco in continuous cropping soil were investigated. Results showed that returning ryegrass to the field increased the thickness of soil humus layer from 13 cm to 15 cm, reduced the humus layer soil bulk density to 1.29 cm/g. Ryegrass tilled and returned to the field increased soil organic matter content by 6.89-7.92%, increased rhizosphere soil available phosphorus content by 2.22-17.96%, and converted the soil non-exchangeable potassium into potassium that was available for plant absorption and utilization. Ryegrass tilling and returning to the field increased the potassium content of middle leaves of flue-cured tobacco by 7.69-10.07%, the increased potassium content in flue-cured tobacco was accompanied by increased total sugar, reducing sugar, and the ratio of reducing sugar to nicotine, which facilitated the harmonization of the chemical composition of cured tobacco leaves. Moreover, the increased number of markedly improved operational taxonomic units enhanced the complexity of the soil bacterial community and its compactness after ryegrass tillage and their return to the field. The available potassium, available phosphorus, total potassium content, pH, and sampling period of the rhizosphere soil had considerable effects on the rhizosphere microbial. Ryegrass tilling and returning to the field changed the soil microbiome, which increased the abundance of bulk soil Proteobacteria, rhizosphere soil Fibrobacterota, and microbes with anti-pathogen activity (); and reduced the abundance of pathogenic fungi genus in the soil. In brief, ryegrass returned to the field, improved soil microecology and restored soil nutrients, and established a new dynamic balance of soil ecology, thereby improving the quality of cultivated land and the quality of flue-cured tobacco.
烟草的广泛持续种植导致了土壤退化以及作物产量和品质下降。绿肥是一种能缓解连作障碍的重要有机肥料。然而，绿肥对烤烟种植的植物-土壤微生态效应仍不清楚。因此，开展了一项定位试验，包括仅施用化肥（NPK处理）和翻压黑麦草并施用化肥（NPKG处理）两种处理，研究了黑麦草还田对连作土壤理化性质、土壤微生物群落、作物产量及烤烟品质的影响。结果表明，黑麦草还田使土壤腐殖质层厚度从13厘米增加到15厘米，腐殖质层土壤容重降至1.29克/立方厘米。翻压黑麦草还田使土壤有机质含量增加6.89%-7.92%，根际土壤有效磷含量增加2.22%-17.96%，并将土壤中难溶性钾转化为可供植物吸收利用的钾。翻压黑麦草还田使烤烟中部叶片钾含量增加7.69%-10.07%，烤烟钾含量增加的同时，总糖、还原糖含量及还原糖与烟碱比值升高，有利于烤后烟叶化学成分协调。此外，显著改善的可操作分类单元数量增加，提高了黑麦草翻压还田后土壤细菌群落的复杂性及其紧密性。根际土壤有效钾、有效磷、全钾含量、pH值及采样时期对根际微生物有较大影响。翻压黑麦草还田改变了土壤微生物群落，增加了土体土壤变形菌门、根际土壤纤维杆菌门及具有抗病原菌活性微生物的丰度（）；降低了土壤中致病真菌属的丰度。总之，黑麦草还田改善了土壤微生态，恢复了土壤养分，建立了土壤生态新的动态平衡，从而提高了耕地质量和烤烟品质。
