National Agricultural Experimental Station for Agricultural Environment, Luhe, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China.
National Agricultural Experimental Station for Agricultural Environment, Luhe, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China; Jiangsu University, Zhenjiang 212023, China.
Sci Total Environ. 2023 Nov 20;900:165916. doi: 10.1016/j.scitotenv.2023.165916. Epub 2023 Jul 29.
The alkaline phosphomonoesterase (ALP)-harboring community (phoD-harboring community) plays a crucial role in the conversion of organic phosphorus (P) into available P (AP). However, the response mechanisms of phoD-harboring communities to fertilization strategies, crop types, and their interactions within the wheat-sweetpotato rotation are poorly understood. A nine-year field experiment of different fertilization strategies was established under the wheat-sweetpotato rotation. After harvesting the crop, we collected soil samples without fertilization (CK), inorganic NK fertilization (NK), inorganic NPK fertilization (NPK), and a combined application of inorganic NPK and organic fertilizer (NPKM). We employed high-throughput sequencing and enzymology techniques to analyze the composition and functional activity of phoD-harboring bacterial communities as well as their correlation with soil physicochemical properties. The results showed that long-term nitrogen (N) fertilization, especially inorganic N, significantly reduced soil pH and ALP activity while increasing AP compared with CK. The AP content in sweetpotato season was significantly higher than that in wheat season. Inorganic N fertilization dramatically reshaped the communities of phoD-harboring bacteria and decreased diversity. The phoD-harboring bacterial communities in sweetpotato season were significantly different from those in wheat season. The N fertilization significantly reduced the relative abundance of Acuticoccus, Methylibium, Rhizobacter, and Roseivivax, which was positively correlated with ALP activity. These groups in sweetpotato season decreased significantly compared with wheat season. A structural equation model indicates that pH and AP play a significant role in regulating the phoD-harboring bacteria communities, ALP activity, and their interactions. We demonstrate that fertilization strategies and crop types have a substantial impact on the phoD-harboring bacteria communities and functions, which are closely linked to soil pH and AP levels. Our study highlights the detrimental effects of soil acidification resulting from inorganic N fertilization on P-cycling bacterial communities and functions. However, the combination of inorganic and organic fertilizer can mitigate these adverse effects.
碱性磷酸单酯酶（ALP）库（phoD 库）在有机磷（P）向有效磷（AP）的转化中起着至关重要的作用。然而，phoD 库对施肥策略、作物类型及其在小麦-甘薯轮作中的相互作用的响应机制还知之甚少。在小麦-甘薯轮作下进行了一项为期九年的不同施肥策略的田间试验。收获作物后，我们采集了无施肥（CK）、无机 NK 施肥（NK）、无机 NPK 施肥（NPK）和无机 NPK 和有机肥结合施用（NPKM）的土壤样本。我们采用高通量测序和酶学技术分析 phoD 库细菌群落的组成和功能活性及其与土壤理化性质的相关性。结果表明，长期施氮，尤其是无机氮，显著降低了土壤 pH 值和 ALP 活性，同时增加了 AP，与 CK 相比。甘薯季的 AP 含量明显高于小麦季。无机 N 施肥极大地改变了 phoD 库细菌群落的结构，降低了多样性。甘薯季的 phoD 库细菌群落与小麦季明显不同。N 施肥显著降低了 Acuticoccus、Methylibium、Rhizobacter 和 Roseivivax 的相对丰度，与 ALP 活性呈正相关。与小麦季相比，这些群体在甘薯季显著减少。结构方程模型表明，pH 值和 AP 对 phoD 库细菌群落、ALP 活性及其相互作用的调节起着重要作用。我们证明，施肥策略和作物类型对 phoD 库细菌群落和功能有很大的影响，这与土壤 pH 值和 AP 水平密切相关。我们的研究强调了无机 N 施肥导致土壤酸化对 P 循环细菌群落和功能的不利影响。然而，无机和有机肥的结合可以减轻这些不利影响。
