Carbon, nitrogen, and phosphorus stoichiometry mediate sensitivity of carbon stabilization mechanisms along with surface layers of a Mollisol after long-term fertilization in Northeast China

• Published in: Journal of soils and sediments Vol. 21; no. 2; pp. 705 - 723
• Main Authors: Abrar, Muhammad Mohsin, Xu, Hu, Aziz, Tariq, Sun, Nan, Mustafa, Adnan, Aslam, Muhammad Wajahat, Shah, Syed Atizaz Ali, Mehmood, Khalid, Zhou, Baoku, Ma, Xingzhu, Chen, Xianni, Xu, Minggang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2021; Springer Nature B.V
• Subjects: Agricultural land; Agricultural practices; Biological fertilization; Carbon; China; Crop rotation; cropland; Cropping systems; Deep layer; Depth; Earth and Environmental Science; Environment; Environmental Physics; Farmyard manure; Fertility; Fertilization; Fertilizer application; Fertilizers; Manures; Microorganisms; Mineral fertilizers; Mollisols; Nitrogen; Nutrient availability; Organic carbon; Phosphorus; Ratios; Regression analysis; Sec 1 • Soil Organic Matter Dynamics and Nutrient Cycling • Research Article; Soil; Soil fertility; Soil investigations; Soil layers; soil organic carbon; soil quality; Soil Science & Conservation; Soil stabilization; Soils; Soybeans; Stabilization; Stoichiometry; subsoil; Subsoils; Surface layers; Topsoil; China; Long-term fertilization; Soil stoichiometry; Soil profile; Protection mechanisms
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-020-02825-7

Purpose Soil organic carbon (SOC) is an important parameter determining soil fertility and sustaining soil health. How C, N, and P contents and their stoichiometric ratios (C/N/P) regulate the nutrient availability, and SOC stabilization mechanisms have not been comprehensively explored, especially in response to long-term fertilization. The present study aimed to determine how the long-term mineral and manure fertilization influenced soil C/N/P ratios and various protection mechanisms underlying the stabilization of OC along with profile in a cropland soil. Materials and methods The soil was sampled from five depths, viz., 0–20 cm, 20–40 cm, 40–60 cm, 60–80 cm, and 80–100 cm, from plots comprising wheat-maize-soybean rotation system subjected to the long-term (35 years) manure and mineral fertilizer applications. Results and discussion Results revealed that the soil C, N, P stoichiometry and their contents in topsoil depths (0–20 and 20–40 cm) and subsoil depths (40–60, 60–80, and 80–100 cm) varied significantly ( p  < 0.01) among the soil layers. Compared with CK, the C, N, and P contents were significantly higher ( p  < 0.05) in NPKM in the topsoil layers, while M alone increased these contents throughout the subsoil. Overall, the C, N, and P contents and their stoichiometry decreased with the increase in depth. Regression analysis showed that C/N, C/P, and N/P ratios associated significantly with the OC fractions in the topsoil layers only. These negative correlations indicated that these ratios significantly influence the C stabilization in the surface layers. However, the results warrant further investigations to study the relationship between soil and microbial stoichiometry and SOC at various depths. Conclusions Long-term manure applications improved the C sequestration not only in the topsoil but also in the deep layers; hence, these facts can be considered relevant for fertilizer recommendations in cropping systems across China.