Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD, 57007, USA.
Department of Plant, Soil, and Microbial Sciences, Michigan State University, East Lansing, MI, 48824, USA.
Sci Rep. 2023 Dec 27;13(1):23042. doi: 10.1038/s41598-023-50110-7.
Long-term fertilizer application in row crops may influence soil pore characteristics, thereby impacting soil aggregation and structure. Therefore, understanding the influences on soil pore characteristics is useful for adopting suitable conservation practices. However, the impact of cattle manure and inorganic fertilizer application at varied rates on soil pore characteristics in the soil profile at a microscale level remains limited. This study quantifies the impacts of manure and inorganic fertilizer amendments under a corn (Zea mays L.)-soybean (Glycine max L.)-spring wheat (Triticum aestivum) rotation system on soil pore characteristics using the X-ray computed tomography (XCT). Treatments included: low manure (LM; 4.4 and 3.3 Mg ha), medium manure (MM; 27.4 and 18.7 Mg ha), high manure (HM; 54.8 and 37.4 Mg ha), medium fertilizer (MF; 136 kg N ha, 49 kg PO ha, and 91.5 kg KO ha), high fertilizer (HF; 204 kg N ha, 73.5 kg PO ha, and 137.3 kg KO ha), and control (CK), respectively, at Brookings (initiated in 2008) and Beresford (2003) in South Dakota. Four intact soil cores were collected from each treatment at 0-10, 10-20, 20-30, and 30-40 cm depths. Results showed that the HM treatment increased the SOC by 8-68% compared to the CK and MF at 0-20 cm at the study sites. Both HM and MM treatments increased the macroporosity and mesoporosity in 0-20 cm soil depths at both study sites. Treatment did not always improve soil pore characteristics below 20 cm soil depth. Additionally, a positive correlation was observed between the XCT-derived macroporosity, total number of macropores, and SOC for all the treatments. Therefore, this study encourages the adoption of the XCT technique in quantifying soil pore characteristics and suggests that long-term medium manure application enhances soil structure as compared to an equivalent inorganic fertilizer application.
长期在作物行施用人粪尿和化肥可能会影响土壤孔隙特征，从而影响土壤团聚体和结构。因此，了解土壤孔隙特征的影响对于采用合适的保护措施是有用的。然而，在微观尺度水平上，不同施肥率下的牛粪和无机肥对土壤剖面中土壤孔隙特征的影响仍然有限。本研究采用 X 射线计算机断层扫描（XCT）技术，量化了玉米（Zea mays L.）-大豆（Glycine max L.）-春小麦（Triticum aestivum）轮作系统下低肥（LM；4.4 和 3.3 Mg ha）、中肥（MM；27.4 和 18.7 Mg ha）、高肥（HM；54.8 和 37.4 Mg ha）、中肥（MF；136 kg N ha、49 kg PO ha 和 91.5 kg KO ha）、高肥（HF；204 kg N ha、73.5 kg PO ha 和 137.3 kg KO ha）和对照（CK）处理对土壤孔隙特征的影响，分别在南达科他州的布鲁金斯（始于 2008 年）和贝雷斯福德（2003 年）进行。从每个处理中采集了 4 个完整的土壤芯，深度分别为 0-10、10-20、20-30 和 30-40 cm。结果表明，与 CK 和 MF 相比，HM 处理在研究地点的 0-20 cm 深度处增加了 8-68%的 SOC。HM 和 MM 处理均增加了两个研究地点 0-20 cm 土壤深度的大孔和中孔。处理并不总是能改善 20 cm 以下土壤深度的土壤孔隙特征。此外，XCT 衍生的大孔、大孔总数和所有处理的 SOC 之间存在正相关关系。因此，本研究鼓励采用 XCT 技术来量化土壤孔隙特征，并表明与等量无机肥相比，长期施用中等量的粪肥可增强土壤结构。
