Liu Ji, Qiu Tianyi, Peñuelas Josep, Sardans Jordi, Tan Wenfeng, Wei Xiaomeng, Cui Yongxing, Cui Qingliang, Wu Chuanfa, Liu Lanfa, Zhou Baitao, He Haoran, Fang Linchuan
Hubei Province Key Laboratory for Geographical Process Analysis and Simulation, Central China Normal University, Wuhan, China.
Department of Ecohydrology, Leibniz Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
Glob Chang Biol. 2023 Apr;29(8):2203-2226. doi: 10.1111/gcb.16584. Epub 2023 Jan 20.
Although soil ecological stoichiometry is constrained in natural ecosystems, its responses to anthropogenic perturbations are largely unknown. Inputs of inorganic fertilizer and crop residue are key cropland anthropogenic managements, with potential to alter their soil ecological stoichiometry. We conducted a global synthesis of 682 data pairs to quantify the responses of soil carbon (C), nitrogen (N), and phosphorus (P) and grain yields to combined inputs of crop residue plus inorganic fertilizer compared with only inorganic fertilizer application. Crop residue inputs enhance soil C (10.5%-12%), N (7.63%-9.2%), and P (2.62%-5.13%) contents, with an increase in C:N (2.51%-3.42%) and C:P (7.27%-8.00%) ratios, and grain yields (6.12%-8.64%), indicating that crop residue alleviated soil C limitation caused by inorganic fertilizer inputs alone and was able to sustain balanced stoichiometry. Moreover, the increase in soil C and C:N(P) ratio reached saturation in ~13-16 years after crop residue return, while grain yield increase trend discontinued. Furthermore, we identified that the increased C, N, and P contents and C:N(P) ratios were regulated by the initial pH and C content, and the increase in grain yield was not only related to soil properties, but also negatively related to the amount of inorganic N fertilizer input to a greater extent. Given that crop residual improvement varies with soil properties and N input levels, we propose a predictive model to preliminary evaluate the potential for crop residual improvement. Particularly, we suggest that part of the global budget should be used to subsidize crop residue input management strategies, achieving to a win-win situation for agricultural production, ecological protection, and climate change mitigation.
尽管土壤生态化学计量在自然生态系统中受到限制，但其对人为扰动的响应在很大程度上仍不清楚。无机肥料和作物残茬的投入是农田主要的人为管理措施，有可能改变土壤生态化学计量。我们对682组数据进行了全球综合分析，以量化与仅施用无机肥料相比，作物残茬加无机肥料联合投入对土壤碳（C）、氮（N）、磷（P）和谷物产量的响应。作物残茬投入提高了土壤C（10.5%-12%）、N（7.63%-9.2%）和P（2.62%-5.13%）含量，C:N（2.51%-3.42%）和C:P（7.27%-8.00%）比值以及谷物产量（6.12%-8.64%）均有所增加，这表明作物残茬缓解了仅由无机肥料投入导致的土壤C限制，并能够维持平衡的化学计量。此外，作物残茬归还后约13-16年，土壤C和C:N（P）比值的增加达到饱和，而谷物产量的增加趋势则停止。此外，我们发现土壤C、N、P含量及C:N（P）比值的增加受初始pH值和C含量的调节，谷物产量的增加不仅与土壤性质有关，在更大程度上还与无机氮肥投入量呈负相关。鉴于作物残茬改良效果因土壤性质和氮输入水平而异，我们提出了一个预测模型来初步评估作物残茬改良的潜力。特别是，我们建议应使用部分全球预算来补贴作物残茬投入管理策略，以实现农业生产、生态保护和气候变化缓解的双赢局面。
