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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.

Integrated crop management practices can improve rice (Oryza sativa L.) grain yield, but the effects of such practices on dry matter accumulation and photosynthetic productivity are inconsistent and not well understood. The primary objective of this study was to investigate the effects of integrated crop management practices on dry matter accumulation and redistribution, photosynthetic production, and yield of rice in northeast China. Medium‐ and high‐yielding potential japonica rice cultivars were grown using four crop management practices, including no N application (N0), local farmers’ cultivation practice (FP), high‐yield cultivation practice (HYP), and super‐high‐yield cultivation practice (SHYP). The increases in average yield with the HYP and SHYP treatments were 16.87 and 36.70%, respectively, in 2017 and 14.70 and 31.05%, respectively, in 2018, compared with FP. Increases in effective panicle number and spikelet number per panicle were the main reason for the increase in yield under the integrated crop management treatments. Compared with FP, the HYP and SHYP treatments significantly increased the population dry matter by 26.40 and 56.64%, respectively, before the heading stage. Relative to N0 and FP, HYP and SHYP significantly increased the dry matter export, export rate, and translocation rate in the leaves, stems, and sheaths and significantly increased the photosynthetic potential throughout the growth stage and the net assimilation rate after the tillering stage. These increases were critical for improving the quality of rice and achieving higher yields. Our study provides a theoretical basis for the development of high‐yield cultivation methods for rice in northeast China.

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.

Dry direct-seeded rice cultivation is a simple and labor-saving planting method wherein the combined application of organic and inorganic fertilizers can improve yield. However, the effects of combined fertilizers on soil properties and bacteria in dry direct-seeded rice paddy soil are unclear. Here, four treatments, conventional fertilization (NPK), seaweed bio-organic fertilizer + NPK, Jishiwang bio-organic fertilizer + NPK, and attapulgite organic fertilizer + NPK applied for three consecutive years were tested to explore their effects on soil physical, chemical, and bacterial community characteristics in a dry direct-seeded rice paddy field. The combined fertilizers increased alkaline hydrolysis-nitrogen and available potassium while decreasing the bulk density and pH; in addition, a marked increase in the relative abundance of soil macroaggregates (>5 mm) and clay particles and a decrease in that of sand was observed. Urease and neutral phosphatase activities were the highest with the Jishiwang organic fertilizer + NPK, whereas invertase and catalase activities were the highest with attapulgite organic fertilizer + NPK. All combined fertilizers considerably increased the bacterial richness index (ACE) and Chao index; Jishiwang bio-organic fertilizer + NPK also increased the Simpson index, whereas the seaweed bio-organic fertilizer + NPK reduced it. Proteobacteria and Acidobacteria accounted for 54.25–70.49% of the total bacterial relative abundance. The relative abundance of Verrucomicrobia, Chloroflexi, Firmicutes, and Nitrospirae increased with the combined fertilizers. The correlation network analysis showed predominant antagonistic relationships. A redundancy analysis demonstrated that total nitrogen, soil organic matter, urease, and invertase were the main environmental factors affecting bacterial composition. Combined fertilizers may improve soil physical and chemical properties, fertility, and bacterial richness.