Key Laboratory of Fertilization from Agricultural Wastes, Ministry of Agriculture and Rural Affairs, Institute of Plant Protection and Soil Fertilizer, Hubei Academy of Agricultural Sciences, Wuhan, Hubei 430064, PR China.
Microelement Research Center, College of Resources and Environment, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
Sci Total Environ. 2022 Oct 1;841:156608. doi: 10.1016/j.scitotenv.2022.156608. Epub 2022 Jun 11.
Traditional fertilization management can damage soil structure and lead to severe soil erosion. The practice of crop straw returning to the field reduces the negative impact of straw burning and improves soil quality. We investigated the effects of these agricultural practices on soil organic carbon components, enzyme activities, and soil microorganisms over 14 years of field experiments. Specifically, we studied four management strategies: no fertilizer or crop straw returning (CK), traditional chemical fertilization (NPK), crop straw returning (S), and crop straw returning with chemical fertilizer (NPKS). We found NPKS treatments significantly (P < 0.05) increased the dissolved organic carbon (DOC), microbial biomass carbon (MBC), particulate organic carbon (POC) and readily oxidized organic carbon (ROC) concentrations by 79.32 %, 82.16 %, 92.46 %, and 104.32 % relative to CK. Furthermore, under NPKS, the activities of soil enzymes related C, N, and P (α-glucosidase (αG), β-glucosidase (βG), cellulase (CBH), xylanase (βX), acetyl β-glucosaminidase (NAG), leucine aminopeptidase (LAP), and acid phosphate (AP)) were increased by 54.66 %, 113.26 %, 76.73 %, 52.41 %, 45.74 %, 56.69 %, and 68.92 % relative to CK, respectively. Redundancy analysis and structural equation modelling showed that straw returning had positive effects on soil microbial community diversity and richness, and also improved microbial activity which is favorable in the degradation of soil carbon. Furthermore, we found that soil fungi were more sensitive than bacteria to changes in soil carbon composition and enzyme activities following straw returning. These results suggest that straw returning combined with chemical fertilizer can be an effective strategy to improve soil labile organic carbon components, enzyme activities, and ecological function of microorganisms.
传统施肥管理会破坏土壤结构，导致严重的土壤侵蚀。作物秸秆还田的做法减少了秸秆焚烧的负面影响，提高了土壤质量。我们通过 14 年的田间试验研究了这些农业措施对土壤有机碳组分、酶活性和土壤微生物的影响。具体来说，我们研究了四种管理策略：不施肥和不还秸秆（CK）、传统化肥（NPK）、秸秆还田（S）和秸秆还田加化肥（NPKS）。我们发现，NPKS 处理显著（P<0.05）增加了溶解有机碳（DOC）、微生物生物量碳（MBC）、颗粒有机碳（POC）和易氧化有机碳（ROC）的浓度，分别比 CK 增加了 79.32%、82.16%、92.46%和 104.32%。此外，在 NPKS 下，与 C、N 和 P 相关的土壤酶活性（α-葡萄糖苷酶（αG）、β-葡萄糖苷酶（βG）、纤维素酶（CBH）、木聚糖酶（βX）、乙酰-β-葡萄糖胺酶（NAG）、亮氨酸氨基肽酶（LAP）和酸性磷酸酶（AP））分别增加了 54.66%、113.26%、76.73%、52.41%、45.74%、56.69%和 68.92%，相对 CK。冗余分析和结构方程模型表明，秸秆还田对土壤微生物群落多样性和丰富度有积极影响，也提高了微生物活性，有利于土壤碳的降解。此外，我们发现，土壤真菌对秸秆还田后土壤碳组成和酶活性的变化比细菌更为敏感。这些结果表明，秸秆还田与化肥相结合是提高土壤易分解有机碳组分、酶活性和微生物生态功能的有效策略。
