Cake fertilizer and dairy manure were used as experimental materials to carry out a 9-year (2012–2020) field experiment in the main rice production areas in the Yangtze River basin. Different fertilization modes were used (no fertilization, CK; chemical fertilizer application alone, HY; reduced fertilization with chemical fertilizer application, RF; cake fertilizer replacement of nitrogen fertilizer, CFR; and dairy manure replacement of nitrogen fertilizer, DMR). Changes in the total rice yield, yield components, absorption of nitrogen, soil pH, organic matter, total nitrogen, and soil bulk density under different fertilization treatments were analyzed. The results show that organic fertilizer replacement leads to a stable and high rice yield. The 9-year average rice yields of the CFR and DMR treatments were 60.0% and 61.5% higher than that of CK. The nitrogen uptake of the CFR and DMR treatments was also higher than that of the other treatments. The nitrogen recovery efficiency in the current season could be increased by 16.37–22.89%, and after 9 years of testing, the soil total nitrogen contents of CFR and DMR increased by 0.23–0.85 g·kg⁻¹ compared to the other treatments. The available P and K contents of DMR increased by 30.17 mg·kg⁻¹ and 22.02 mg·kg⁻¹ compared with HY, respectively. The soil bulk density was reduced by 0.08 g·cm⁻³. Generally, the effects of dairy manure replacement were better than those of cake fertilizer. This is an important method that can be used to fertilize the soil and foster sustainable soil utilization in the rice-growing area of the Yangtze River Basin, as a long-term partial replacement for chemical nitrogen fertilizer.

As an cultivated aquatic vegetable, the long-term continuous monocropping of water oat results in the frequent occurrence of diseases, the deterioration of ecological system and decreased quality of water oat. In this study, real-time quantitative PCR (qPCR) and Illumina high-throughput sequencing were used to determine the dynamic changes in bacterial and fungal communities in rhizosphere soil under continuous cropping of water oat for 1, 5, 10, 15 and 20 years (Y1, Y5, Y10, Y15 and Y20), and soil properties and enzyme activities were also determined. Results showed that the contents of soil organic carbon (SOC), total nitrogen (TN), alkali-hydrolyzable nitrogen (AN), available phosphorus (AP) and the activities of four soil enzymes increased in Y5 and Y10 and then decreased in Y15 and Y20. Spearman correlation analysis identified SOC, TN, AP and AN as the main factors that affect the four enzyme activities. The qPCR results showed that there was no significant difference in bacterial abundance between the different planting years, while the fungal abundance first increased and then decreased. The long-term continuous planting of water oat (Y15 and Y20) significantly reduced the operational taxonomic unit numbers and the Shannon, Chao1, and ACE indices of rhizosphere bacteria and fungi. The bacterial and fungal community compositions were markedly affected by the continuous planting year. The relative abundances of Bacteroidetes and Firmicutes decreased significantly in Y10 and Bacteroidetes increased significantly in Y15. Relative abundances of dominated Mortierellomycota and Ascomycota phyla increased with the continuous cropping years, while Rozellomycota presented the opposite trend. The AK, AN, and SOC were the main factors that changed the bacterial community, while AK and AP significantly shifted the fungal community. Thus, long-term continuous planting of water oat resulted in the deterioration of soil nutrients and microbial communities. The results provided a reference for the remediation of soil under continuous water oat planting and sustainable development of water oat industry.

Long-term reliance on mineral fertilizers may degrade soil structure and weaken carbon and nitrogen retention in rice–wheat rotation systems. Organic amendments combined with mineral fertilizers can provide organic substrates, promote aggregate formation, and improve soil C–N retention, but the contrasting effects of plant- and animal-derived amendments remain unclear. A long-term field experiment initiated in 2012 in Chaohu, China, compared no fertilization (CK), chemical fertilizer alone (CF), chemical fertilizer plus oil cake (OC), and chemical fertilizer plus cattle manure (CM). At wheat maturity in 2025, soil aggregate distribution, stability, aggregate-associated soil organic carbon (SOC) and total nitrogen (TN), C and N contribution rates, and yield components were determined; wheat yield was further evaluated using annual records from 2021 to 2025. Compared with CK, OC and CM increased water-stable macroaggregates (>0.25 mm) by 17.35% and 17.94% and reduced aggregate destruction by 54.61% and 53.57%, respectively. In large macroaggregates (>2 mm), OC and CM increased SOC by 58.30% and 84.83% and TN by 141.76% and 200.00%, respectively. Five-year mean yield increased by 208.09%, 240.78%, and 225.15% under CF, OC, and CM, respectively, relative to CK, but did not differ significantly among fertilized treatments. Overall, oil cake showed a numerical advantage in maintaining wheat yield, whereas cattle manure had greater potential to improve aggregate-scale C–N retention and soil structural stability.

(1) Background: We investigated the effects of nutrient levels on rice yield and nitrogen uptake, with the aim of improving rice yield and nitrogen use efficiency. (2) Methods: A 3-year field experiment was conducted using the rice variety Changliangyou Fuxiangzhan, with six treatments: no nitrogen application (CK), conventional fertilization (FP), single basal application of 60-day slow-release urea (CRU1), single basal application of urea combined with 40-day and 90-day slow-release urea (CRU2), partial substitution of chemical fertilizer with bio-organic manure (FPM), and conventional fertilization combined with straw return (FPS). (3) Results: Different nutrient management regimes significantly affected rice yield and nitrogen uptake and use, as well as soil nitrogen content. CRU2 achieved the highest performance across most indicators, with grain yield averaging 9.6% higher than that of FP and 36.4% higher than that of CK, alongside consistently greater effective panicle numbers. It also significantly enhanced nitrogen uptake, with higher grain and straw N accumulation, and showed the best nitrogen use efficiencies. Soil responses varied by treatment: FPS and FPM increased total nitrogen, while CRU2 and CRU1 had the highest inorganic nitrogen, and microbial biomass nitrogen peaked under FPM, CRU2, and FPS. Despite these benefits, CRU2 showed the largest negative nitrogen balance, averaging −33.0 kg ha⁻¹ over 3 years. (4) Conclusions: The CRU2 treatment achieved efficient synchronization between nitrogen supply and demand, with the highest yield, nitrogen uptake, and soil nitrogen levels.

Against the backdrop of escalating global climate challenges, minimizing carbon emissions while enhancing energy efficiency in rice production has emerged as a core pathway toward achieving agricultural carbon neutrality. A two-year field study conducted in the Yangtze River Delta evaluated three rice cultivation practices: the farmers’ practice pattern (FPP), surface-applied controlled-release fertilizer with machine transplanting (S-CRF), and side-deep applied controlled-release fertilizer with machine transplanting (SD-CRF). Compared to FPP and S-CRF, SD-CRF increased grain yields by 11.3% and 9.2%, respectively, while reducing total energy input by 2.5% and 2.4%. It lowered the carbon intensity of production by 9.7% and 8.2% relative to FPP and S-CRF, primarily through reducing fertilizer/labor-associated carbon inputs and enhancing carbon-use efficiency via higher yield. Economically, SD-CRF outperformed traditional practices, achieving an 81.8% increase in net income and a 37.4% higher benefit-to-cost ratio compared with FPP, respectively, driven by labor cost savings and improved productivity. Notably, SD-CRF reduces labor input by 40.0% compared with FPP, simplifies fertilization operations, lowers farmers’ operational technical thresholds, and effectively boosts their economic income. Data envelopment analysis (DEA) further validated SD-CRF’s superior eco-efficiency, highlighting its dual advantage in balancing yield enhancement and environmental sustainability. Further clarification of SD-CRF application technical indicators, refinement of agronomic practices and machinery efficiency, and promotion of the integrated system’s synergistic benefits and scalable adoption are required to support global sustainable food systems and carbon neutrality goals.