Yang Yuanyu, Zhang Jianwei, Chang Xia, Chen Lunlun, Liu Yongmin, Xu Qingwei, Wang Mengjuan, Yu Haiyan, Huang Renmei, Zhang Jie, Hu Yingxiao, Hu Qijuan, Shi Xiaojun, Zhang Yuting
College of Resources and Environment, Southwest University, Chongqing, China.
Interdisciplinary Research Center for Agriculture Green Development in Yangtze River Basin, Southwest University, Chongqing, China.
Front Plant Sci. 2024 Feb 26;15:1356224. doi: 10.3389/fpls.2024.1356224. eCollection 2024.
The incorporation of green manures substantially enhances the conversion of external phosphorus (P) fertilizers and soil-reserved P into forms readily available to plants. The study aims to evaluate the influence of green manure additions on soil phosphorus dynamics and citrus growth, considering different green manure species and initial soil phosphorus levels. Additionally, the research seeks to elucidate the microbiological mechanisms underlying the observed effects.
A citrus pot experiment was conducted under both P-surplus (1.50 g·P·kg) and P-deficient (0.17 g·P·kg) soils with incorporating legume (Leg), non-legume (Non-Leg) or no green manure residues (CK), and O-P labeled KHPO (0.5 g, containing 80‰ δO) was additionally introduced to trace the turnover characteristics of chemical P fertilizer mediated by soil microorganisms.
In P-surplus soil, compared with the CK treatment, the Leg treatment significantly increased soil HO-P (13.6%), NaHCO-P (8.9%), NaOH-P (9.5%) and NaOH-P (30.0%) content. It also promoted rapid turnover of P sources into HO-P and NaHCO-P pools by enhancing the (576.6%) gene abundance. In contrast, the Non-Leg treatment significantly augmented soil HO-P (9.2%) and NaHCO-P (8.5%) content, facilitating the turnover of P sources into NaHCO-P pools. Under P-deficient soil conditions, compared with the CK treatment, the Leg treatment notably raised soil HO-P (150.0%), NaHCO-P (66.3%), NaHCO-P (34.8%) and NaOH-P (59.0%) content, contributing to the transfer of P sources into NaHCO-P and NaOH-P pools. This effect was achieved through elevated ALP (33.8%) and ACP (12.9%) activities and increased (48.1%), (42.9%), (21.7%), and (27.4%) gene abundances. The Non-Leg treatment, on the other hand, led to significant increases in soil NaHCO-P (299.0%) and NaHCO-P (132.6%) content, thereby facilitating the turnover of P sources into NaHCO-P and NaOH-P pools, except for the gene abundance. Both Leg and Non-Leg treatments significantly improved citrus growth (7.3-20.0%) and P uptake (15.4-42.1%) in P-deficient soil but yielded no substantial effects in P-surplus soil. In summary, introducing green manure crops, particularly legume green manure, emerges as a valuable approach to enhance soil P availability and foster fruit tree growth in orchard production.
绿肥的施入显著提高了外源磷肥和土壤储备磷向植物易利用形态的转化。本研究旨在评估不同绿肥种类和初始土壤磷水平下，绿肥添加对土壤磷动态及柑橘生长的影响。此外，该研究还试图阐明观察到的效应背后的微生物学机制。
在磷盈余（1.50 g·P·kg）和磷缺乏（0.17 g·P·kg）的土壤上进行柑橘盆栽试验，分别添加豆科绿肥（Leg）、非豆科绿肥（Non-Leg）或不添加绿肥残渣（CK），并额外引入O-P标记的KHPO（0.5 g，含80‰ δO）来追踪土壤微生物介导的化学磷肥周转特征。
在磷盈余土壤中，与CK处理相比，Leg处理显著增加了土壤HO-P（13.6%）、NaHCO-P（8.9%）、NaOH-P（9.5%）和NaOH-P（30.0%）含量。通过提高（576.6%）基因丰度，它还促进了磷源快速周转至HO-P和NaHCO-P库。相反，Non-Leg处理显著增加了土壤HO-P（9.2%）和NaHCO-P（8.5%）含量，促进了磷源周转至NaHCO-P库。在磷缺乏土壤条件下，与CK处理相比，Leg处理显著提高了土壤HO-P（150.0%）、NaHCO-P（66.3%）、NaHCO-P（34.8%）和NaOH-P（59.0%）含量，有助于磷源向NaHCO-P和NaOH-P库的转移。这一效果是通过提高ALP（33.8%）和ACP（12.9%）活性以及增加（48.1%）、（42.9%）、（21.7%）和（27.4%）基因丰度实现的。另一方面，Non-Leg处理导致土壤NaHCO-P（299.0%）和NaHCO-P（132.6%）含量显著增加，从而促进了磷源向NaHCO-P和NaOH-P库的周转，但基因丰度除外。Leg和Non-Leg处理在磷缺乏土壤中均显著改善了柑橘生长（7.3 - 20.0%）和磷吸收（15.4 - 42.1%），但在磷盈余土壤中未产生显著影响。总之，引入绿肥作物，特别是豆科绿肥，是提高果园土壤磷有效性和促进果树生长的一种有价值的方法。
