The co-pyrolysis of biomass and soluble phosphates generates biochar-based phosphate fertilizers (BBF), which may enhance phosphorus (P) input in soil and P uptake by plants. Conversely, pyrolysis of biomass impregnated with rock phosphate results in low P solubility and may not supplement plant requirement in short term. However, bacterial strains promoting rock phosphate solubilization increases P use efficiency and can be applied to BBFs. An in vitro assay was conducted to investigate the solubilization profile of five bacterial strains (Pseudomonas sp.—UFPI-B5-8A, Burkholderia fungorum—UFLA 04-155, Acinetobacter sp.—UFLA 03-09, Paenebacillus kribbensis—UFLA 03-10, and Paenibacillus sp.—UFLA 03-116) isolated from common bean and cowpea nodules in a rock phosphate BBF. Additionally, a pot trial was carried out aiming to investigate the influence on maize growth by inoculation of three selected strains under a rock phosphate BBF fertilization. Inoculations with UFPI B5-8A, UFLA 04-155, and UFLA 03-09 were efficient in solubilizing P in vitro, being closely associated with pH decrease, likely due to the release of organic acids. As for the pot trial, the dose of 400 mg kg−1 of P in the BBF using UFPI B5-8A significantly increased maize shoot dry matter. All strains significantly enhanced P availability in the soil. Bacterial inoculation in biochar-based rock phosphate aiming to improve its fertilizer value is an inexpensive and sustainable strategy to improve maize growth and enhance available P in soil and should be further explored.

中文翻译：

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某些细菌菌株可提高生物炭基磷矿石肥料中磷的利用率

生物质和可溶性磷酸盐的共热解产生基于生物炭的磷酸盐肥料（BBF），这可能会增加土壤中的磷（P）输入和植物对磷的吸收。相反，浸渍了磷酸盐岩的生物质的热解导致磷的溶解度低，短期内可能无法补充植物的需求。但是，促进磷矿溶解的细菌菌株可提高磷的利用效率，并可应用于BBF。进行了一项体外测定，以研究五种细菌菌株（假单胞菌属-UFPI-B5-8A，真菌伯克霍尔德菌-UFLA 04-155，不动杆菌属-UFLA 03-09，克氏杆菌-UFLA 03-10）的增溶特性。 ，和Paenibacillus sp.-UFLA 03-116）从磷酸盐岩BBF中的普通豆和cow豆根瘤中分离出来。另外，进行了一项盆栽试验，旨在研究在磷矿BBF施肥下接种三种选定菌株对玉米生长的影响。用UFPI B5-8A，UFLA 04-155和UFLA 03-09进行的接种可有效溶解体外的P，与pH降低密切相关，这很可能是由于有机酸的释放所致。至于盆栽试验，使用UFPI B5-8A的BBF中400 mg kg-1的P剂量显着增加了玉米茎干物质。所有菌株均显着提高了土壤中磷的利用率。旨在提高其肥料价值的基于生物炭的磷酸盐岩中的细菌接种是一种廉价且可持续的策略，可改善玉米生长并增加土壤中的有效磷，应进一步探索。