Background: Phosphate-solubilizing bacteria (PSB) can enhance plant growth and phosphorus (P) solubilization, it also has been reported to reduce the negative effects of overused agricultural fertilizer in farmland and protect the soil environment. However, the mechanism behind this interaction has not been fully elucidated. Results: In this study, we screened out Pseudomonas moraviensis, Bacillus safensis, and Falsibacillus pallidus which can both solubilize P efficiently and produce indole-3-acetic acid (IAA) from sandy fluvo-aquic soils. The yield of wheat (Triticum aestivum) under PSB inoculation significantly increased up to 14.42% (P < 0.05) compared with the control treatment in phosphate fertilizer-used farmland. Besides promoting wheat growth, we found the labile P fraction in soil was significantly increased by over 122.04% (P < 0.05) under PSB inoculation compared with it in soils without, in parallel, the stable P fraction was significantly reduced by over 46.89% (P < 0.05). Furthermore, PSB inoculation increased the soil microbial biomass and activity, indicating that PSB screened out in this work performed a remarkable ability to colonize the soils in the wheat field. Conclusion: PSB from sandy fluvo-aquic soil improve wheat growth and crop productivity by increasing the labile P fraction and IAA content in the greenhouse and wheat field. Our work provides an environment and economy-friendly bacterial resource that potentially promotes sustainable agricultural development in the long term.

Background: Manure and biochar soil amendments have shown many benefits to soil quality and crop productivity. This study aimed to reveal the effects of biochar and manure applications on soil fertility improvement and crop productivity in yellow cinnamon soil.Results: This study based on a 5-year field experiment. Four treatments were designed, included the control (CK), biochar amendment, manure amendment, and both biochar and manure amendment (BM). The results showed that: after five years, both biochar and manure treatment improved soil structure by increasing soil mean weight diameter (MWD), and soil water and nutrient supply was also increased by increasing the contents of water content, available potassium and available phosphorus. The productivity was also enhanced as wheat yield under the biochar, manure, and BM treatments increased by 3.59–11.32% compared with CK. In addition, biochar and manure treatment increased soil microbial biomass carbon (MBC) by > 15%, and soil total nematode abundance was significantly increased. Furthermore, the nematode community structure was significantly affected by biochar and manure treatment, dominant trophic group in CK was herbivores, but bacterivores were dominant in the biochar and manure treatments. The distribution of nematode genera was closely related to soil chemical properties and microbial biomass. Increases in the Shannon's diversity index, and decreases in the dominance index and summed maturity index after the 5-year treatment indicated a sustainable soil ecosystem after the biochar and manure applications.Conclusions: These findings indicate that biochar and manure result in better soil quality and increased productivity in yellow cinnamon soil.

"Stimulatory effects of bacterial-feeding nematodes on plant growth vary with nematode species" published on 01 Jan 2011 by Brill.