Impact of Different Biochars on Microbial Community Structure in the Rhizospheric Soil of Rice Grown in Albic Soil.

The purpose of this study was to clarify the effects of biochar on the diversity of bacteria and fungi in the rice root zone and to reveal the changes in soil microbial community structure in the root zone after biochar application to provide a scientific basis for the improvement of albic soil. Rice and corn stalk biochar were mixed with albic soil in a pot experiment. Soil samples were collected at the rice maturity stage, soil nutrients were determined, and genomic DNA was extracted. The library was established using polymerase chain reaction (PCR) amplification. The abundance, diversity index, and community structure of the soil bacterial 16SrRNA gene V3 + V4 region and the fungal internal transcribed spacer-1 (ITS1) region were analyzed using Illumina second-generation high-throughput sequencing technology on the MiSeq platform with related bioinformatics. The results revealed that the biochar increased the soil nutrient content of albic soil. The bacteria ACE indexes of treatments of rice straw biochar (SD) and corn straw biochar (SY) were increased by 3.10% and 2.06%, respectively, and the fungi ACE and Chao indices of SD were increased by 7.86% and 14.16%, respectively, compared to conventional control treatment with no biochar (SBCK). The numbers of bacterial and fungal operational taxonomic units (OUT) in SD and SY were increased, respectively, compared to that of SBCK. The relationship between soil bacteria and fungi in the biochar-treated groups was stronger than that in the SBCK. The bacterial and fungal populations were correlated with soil nutrients, which suggested that the impacts of biochar on the soil bacteria and fungi community were indirectly driven by alternation of soil nutrient characteristics. The addition of two types of biochar altered the soil microbial community structure and the effect of rice straw biochar treatment on SD was more pronounced. This study aimed to provide a reference and basic understanding for albic soil improvement by biochar, with good application prospects.

Effects of chemical-based fertilizer replacement with biochar-based fertilizer on albic soil nutrient content and maize yield.

Biochar-based fertilizers are used to improve soil's physiochemical and biological properties and increase fertilizer utilization rate. Therefore, a technological model of biochar-based fertilizers is essential for the reduced application. This study was conducted to determine the effects of the different levels of biochar-based fertilizer applications on soil and plant nutrient content, as well as maize yield. Biochar-based fertilizer increased the total N content of maize stem and kernel and the total P content of maize axis and kernel. Biochar-based fertilizer increased the total P but decreased the total K of maize plants while increasing the fertilizer's partial productivity. Treatment B1 (600.00 kg hm-2 of biochar-based fertilizer) increased the dry-matter weight of the maize at silking and filling stages by 1.60 and 15.83%. Treatment B1 increased the ear length, diameter, and plant height. Compared with BCK (600.00 kg hm-2 of conventional fertilizer), the yield of B1 was increased by 9.23%, and the difference was significant (p < 0.05). Biochar-based fertilizer treatments B2-B5 (biochar-based fertilizer reduced by 5-20%) reduced maize yield, but there was no significant difference between their yield and BCK. This study aimed to provide a basic understanding and reference for maize fertilizer reduction with good application prospects.