Soil organic matter serves as a crucial indicator for soil quality. Albic soil, characterized by a barrier layer, exhibits limitations in organic matter content, which can adversely affect crop growth and development. To elucidate the impact of deep mixing of various organic materials on the redistribution of organic matter in the surface soil of albic soil could provide theoretical and technical insights for establishing suitable plough layers for albic soil in Northeast China. We conducted a two-year positioning experiment in Shuangyashan, Heilongjiang Province with five treatments, conventional shallow tillage (0-15 cm, CK), inversion tillage (0-35 cm) without or with straw return (T35 and T35+S), inversion tillage with cattle manure (T35+M) and cattle manure plus maize straw (T35+S+M). The results showed that soil fertilization via deep mixing of organic materials to a depth of 35 cm significantly increased maize yield in albic soil, with the T35+S+M treatment demonstrating the most pronounced effect, yielding an average production of 2934.76 kg·hm-2. Compared to CK, the T35 treatment resulted in a significant 8.4% decrease in organic matter content in the tillage layer, a significant 7.6% increase in organic matter in the sub-tillage layer, and a relative richness degree of soil organic matter in the sub-tillage layer increased by 17.5%. Deep mixed return of organic materials following deep ploughing markedly increased organic matter content of the plough layer, with organic matter conversion ranging from 16.3% to 31.0%. In comparison to the T35 treatment, there was no significant increase in soil organic matter content in the T35+S tillage layer and sub-tillage layer. Conversely, soil organic matter content increased by 4.6% and 6.9% in the T35+M and T35+S+M treatments, with corresponding increase of 11.2% and 15.4% in sub-tillage layer, respectively. Additionally, the soil organic matter richness index in sub-tillage layer increased by 2.5% and 5.1%, respectively. There was a significant positive correlation between organic matter content in the entire plough layer and maize yield, with a contribution rate of 17.5%. Therefore, the utilization of organic fertilizer or a combination of organic fertilizer and straw deep mixing can quickly fertilize albic soil by increasing soil organic matter content in both the whole tillage layer (0-35 cm) and the sub-tillage layer (15-35 cm).
土壤有机质是表征土壤质量的重要指标,白浆土作为具有典型障碍层的土壤,其低有机质含量易对作物生长发育产生不良影响,明确不同有机物料深混对白浆土表层土壤有机质再分布的影响,可为东北农田白浆土构建适宜的耕层提供理论和技术参考。本研究在黑龙江省双鸭山市白浆土上进行了为期2年的定位试验,设置5种处理:深翻35 cm(T35)、秸秆深混35 cm(T35+S)、有机肥深混35 cm(T35+M)、秸秆搭配有机肥深混35 cm(T35+S+M),以农民常规措施(浅翻15 cm,CK)为对照。结果表明: 有机物料深混35 cm还田处理(T35+S、T35+M和T35+S+M)可显著提升玉米产量,其中以T35+S+M处理对玉米产量的提升效果最显著,2年平均增产2934.76 kg·hm-2。与CK相比,T35处理耕层(0～15 cm)土壤有机质含量降低8.4%,而亚耕层(15～35 cm)土壤有机质含量增加7.6%,亚耕层土壤有机质丰富度指数增加17.5%。在深翻基础上有机物料还田可显著提升全耕层(0～35 cm)土壤有机质含量,全耕层土壤有机质转化率为16.3%～31.0%。与T35处理相比,T35+S处理耕层和亚耕层土壤有机质含量无显著增加,T35+M和T35+S+M处理耕层土壤有机质含量分别显著增加4.6%和6.9%,亚耕层土壤有机质含量分别显著增加11.2%和15.4%,亚耕层土壤有机质丰富度指数分别增加2.5%和5.1%。相关性分析表明,全耕层土壤有机质含量与玉米产量呈显著正相关,贡献率达17.5%。综上,有机肥或有机肥配合秸秆深混还田是培肥白浆土的有效措施,且主要是通过提升全耕层(0～35 cm)与亚耕层(15～35 cm)土壤有机质含量实现。.

Fresh produce is suggested to contribute highly to shaping the gut resistome. We investigated the impact of pig manure and irrigation water quality on microbiome and resistome of field-grown lettuce over an entire growth period. Lettuce was grown under four regimes, combining soil amendment with manure (with/without) with sprinkler irrigation using river water with an upstream wastewater input, disinfected by UV (with/without). Lettuce leaves, soil, and water samples were collected weekly and analyzed by bacterial cultivation, 16S rRNA gene amplicon sequencing, and shotgun metagenomics from total community DNA. Cultivation yielded only few clinically relevant antibiotic-resistant bacteria (ARB), but numbers of ARB on lettuce increased over time, while no treatment-dependent changes were observed. Microbiome analysis confirmed a temporal trend. Antibiotic resistance genes (ARGs) unique to lettuce and water included multidrug and β-lactam ARGs, whereas lettuce and soil uniquely shared mainly glycopeptide and tetracycline ARGs. Surface water carried clinically relevant ARB (e.g. ESBL-producing Escherichia coli or Serratia fonticola) without affecting the overall lettuce resistome significantly. Resistance markers including biocide and metal resistance were increased in lettuce grown with manure, especially young lettuce (increased soil contact). Overall, while all investigated environments had their share as sources of the lettuce resistome, manure was the main source especially on young plants. We therefore suggest minimizing soil-vegetable contact to minimize resistance markers on fresh produce.

Conjugative plasmids are important vectors of mobile antibiotic resvistance genes (ARGs), facilitating their horizontal transfer within the environment. While composting is recognized as an effective method to reduce antibiotics and ARGs in animal manure, its impact on the bacterial host communities containing antibiotic-resistant plasmids remains unclear. In this study, we investigated the permissiveness of bacterial community during composting when challenged with multidrug-resistant conjugative RP4 plasmids, employing Pseudomonas putida as the donor strain. Ultimately, this represents the first exploration of the effects of aeration rates on the range of RP4 plasmid transfer hosts. Transconjugants were analyzed through fluorescent reporter gene-based fluorescence-activated cell sorting and Illumina sequencing. Overall, aeration rates were found to influence various physicochemical parameters of compost, including temperature, pH, total organic matter, total nitrogen, and potassium. Regarding RP4 plasmid host bacteria, the dominant phylum was determined to shift from Bacteroidetes in the raw material to Proteobacteria in the compost. Notably, a moderate-intensity aeration rate (0.05 L/min/L) was found to be more effective in reducing the diversity and richness of the RP4 plasmid host bacterial community. Following composting, the total percentage of dominant transconjugant-related genera decreased by 66.15-76.62%. Ultimately, this study determined that the aeration rate negatively impacts RP4 plasmid host abundance primarily through alterations to the environmental factors during composting. In summary, these findings enhance our understanding of plasmid host bacterial communities under varying composting aeration rates and offer novel insights into preventing the dissemination of ARGs from animal manure to farmland.

Microalgae biomass products are gaining popularity due to their diverse applications in various sectors. However, the costs associated with media ingredients and cell harvesting pose challenges to the scale-up of microalgae cultivation. This study evaluated the growth and nutrient removal efficiency (RE) of immobilized microalgae Tetradesmus obliquus in sodium alginate beads cultivated in swine manure-based wastewater compared to free cells. The main findings of this research include (i) immobilized cells outperformed free cells, showing approximately 2.3 times higher biomass production, especially at 10% effluent concentration; (ii) enhanced organic carbon removal was observed, with a significant 62% reduction in chemical oxygen demand (383.46-144.84 mg L-1) within 48 h for immobilized cells compared to 6% in free culture; (iii) both immobilized and free cells exhibited efficient removal of total nitrogen and total phosphorus, with high REs exceeding 99% for phosphorus. In addition, microscopic analysis confirmed successful cell dispersion within the alginate beads, ensuring efficient light and substrate transfer. Overall, the results highlight the potential of immobilization techniques and alternative media, such as biodigested swine manure, to enhance microalgal growth and nutrient RE, offering promising prospects for sustainable wastewater treatment processes.

To achieve the purpose of treating waste by waste, in this study, a nitrogen-doped Fe/Mn bimetallic biochar material (FeMn@N-BC) was prepared from chicken manure for persulfate activation to degrade Bisphenol A (BPA). The FeMn@N-BC was characterized by scanning electron microscopy (SEM), X-ray diffract meter (XRD), fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectrometer (XPS) and found that N doping can form larger specific surface area. Catalytic degradation experiments showed that Fe/Mn bimetal doping not only accelerated the electron cycling rate on the catalyst surface, but also makes the biochar magnetic and easy to separate, thus reducing environmental pollution. Comparative experiments was concluded that the highest degradation efficiency of BPA was achieved when the mass ratios of urea and chicken manure, Fe/Mn were 3:1 and 2:1, respectively, and the pyrolysis temperature was 800 °C, which can almost degrade all the BPA in 60 min. FeMn@N-BC/PS system with high catalytic efficiency and low consumables is promising for reuse of waste resources and the remediation of wastewater.

UNASSIGNED: Soil-borne pathogens cause considerable crop losses and food insecurity in smallholder systems of sub-Saharan Africa. Soil and crop testing is critical for estimating pathogen inoculum levels and potential for disease development, understanding pathogen interactions with soil nutrient and water limitations, as well as for developing informed soil health and disease management decisions. However, formal laboratory analyses and diagnostic services for pathogens are often out of reach for smallholder farmers due to the high cost of testing and a lack of local laboratories.
UNASSIGNED: To address this challenge, we assessed the performance of a suite of simplified soil bioassays to screen for plant parasitic nematodes (e.g., Meloidogyne, Pratylenchus) and other key soil-borne pathogens (Pythium and Fusarium). We sampled soils from on-farm trials in western Kenya examining the impact of distinct nutrient inputs (organic vs. synthetic) on bean production. Key soil health parameters and common soil-borne pathogens were evaluated using both simple bioassays and formal laboratory methods across eleven farms, each with three nutrient input treatments (66 samples in total).
UNASSIGNED: The soil bioassays, which involved counting galls on lettuce roots and lesions on soybean were well correlated with the abundance of gall forming (Meloidogyne) and root lesion nematodes (e.g., Pratylenchus) recovered in standard laboratory-based extractions. Effectiveness of a Fusarium bioassay, involving the counting of lesions on buried bean stems, was verified via sequencing and a pathogenicity test of cultured Fusarium strains. Finally, a Pythium soil bioassay using selective media clearly distinguished pathogen infestation of soils and infected seeds. When examining management impact on nematode communities, soils amended with manure had fewer plant parasites and considerably more bacterivore and fungivore nematodes compared to soils amended with synthetic N and P. Similarly, Pythium presence was 35% lower in soils amended with manure, while the Fusarium assays indicated 23% higher Fusarium infection in plots with amended manure. Our findings suggest that relatively simple bioassays can be used to help farmers assess soil-borne pathogens in a timely manner, with minimal costs, thus enabling them to make informed decisions on soil health and pathogen management.

The combined application of manure and mineral fertilizer represents an effective strategy for enhancing crop yield. However, the relationship between soil fertility and crop yield remains unclear in saline-alkaline soil. Here, a 9-year field experiment (2015-2023) was conducted to investigate the effects of manure application and crop rotations on crop yield and economic efficiency as well as potential associated mechanisms in the Hetao Irrigation District. The results showed that in the third cropping rotation cycle, combined application of manure and mineral fertilizers (NPKO) caused a 6.2%, 38.9%, 65.3%, and 132.2% increase in wheat, sunflower, wheat equivalent yield, and the economic income of sunflower, respectively. The average grain yield had a positive correlation with soil organic matter and nutrient supply. This suggested that the soil organic matter had a positive effect on the crop yield due to its impact on nutrient supply. Simultaneously, the sunflower seed setting rate increased by 65.2% under NPKO. The linear regression model revealed that each additional input of 20 Mg ha-1 of manure resulted in an increase of 3.56 kg ha-1 in crop phosphorus harvest and a 0.05 Kg ha-1 increase in wheat equivalent yield compared to NPK. In conclusion, our results highlighted that manure application promotes soil properties and improves crop yield.

Antibiotic resistance genes (ARGs) are widespread in the environment, and soils, specifically, are hotspots for microorganisms with inherent antibiotic resistance. Manure and sludge used as fertilizers in agricultural production have been shown to contain vast amounts of ARGs, and due to continued applications, ARGs accumulate in agricultural soils. Some soils, however, harbor a resilience capacity that could depend on specific soil properties, as well as the presence of predatory bacteria that are able to hydrolyse living bacteria, including bacteria of clinical importance. The objectives of this study were to (i) investigate if the antibiotic resistance profile of the soil microbiota could be differently affected by the addition of cow manure, chicken manure, and sludge, and (ii) investigate if the amendments had an effect on the presence of predatory bacteria. The three organic amendments were mixed separately with a field soil, divided into pots, and incubated in a greenhouse for 28 days. Droplet digital PCR (ddPCR) was used to quantify three ARGs, two predatory bacteria, and total number of bacteria. In this study, we demonstrated that the choice of organic amendment significantly affected the antibiotic resistance profile of soil, and promoted the growth of predatory bacteria, while the total number of bacteria was unaffected.

Applying organic manure to crops positively impacts the soil microbial community which is negatively impacted when chemical fertilizers are used. Organic manures also add new microbes to the soil in addition to influencing the growth of native ones. Metagenomic analysis of different organic manures, soil, and pot culture experiments conducted under various fertilizer conditions constitute the primary methodologies employed in this study. We compared the effect of two organic manure combinations and an inorganic fertilizer combination on microbial community of rhizosphere soil and leaves of sunflower plants. Metagenomic sequencing data analysis revealed that the diversity of bacteria and fungi is higher in organic manure than in chemical fertilizers. Each organic manure combination selectively increased population of some specific microbes and supported new microbes. Application of chemical fertilizer hurts many plant beneficial fungi and bacteria. In summary, our study points out the superiority of organic manure combinations in enhancing microbial diversity and supporting beneficial microbes. These findings enhance the profound influence of fertilizer types on sunflower microbial communities, shedding light on the intricate dynamics within the rhizosphere and leaf microbiome. Bacterial genera such as Bacillus, Serratia, Sphingomonas, Pseudomonas, Methylobacterium, Acinetobacter, Stenotrophomonas, and fungal genera such as Wallemia, Aspergillus, Cladosporium, and Penicillium constitute the key microbes of sunflower plants.

Striking the right nutrient balance is essential for sustainable farming and ecosystem health. In this regard, field experiments were conducted in three phases viz., fertility gradient experiment, main experiment and validation experiment through a soil test crop response approach to develop and validate fertilizer prescription equations for sweet corn in comparison with general recommended dose and soil fertility rating approach. The soil data, fresh cob yield, and NPK uptake were used for establishing four important basic parameters, viz., nutrient requirement (kg t-1), contribution of nutrients from fertilizers, soil, and organic manure. The results revealed that nutrients required to produce one tonne of fresh cob yield (NR) were 5.85 kg, 0.87 kg and 4.31kg for N, P and K, respectively under the STCR NPK alone approach and 6.07 kg, 0.92 kg and 4.33 kg for N, P and K, respectively under STCR NPK+FYM approach. In the validation experiment, STCR NPK+FYM approach for the targeted yield of 25 t ha-1 recorded higher fresh cob yield (23.38 t ha-1) and dry stover yield (35.07 t ha-1) which were significantly higher compared to general recommended dose and soil fertility rating approach. The developed STCR equations for the aforesaid crop are valid as the percent deviation of cob yield from the targeted yield was within ±10%. Similarly, highest nutrient use efficiency was achieved with the STCR approach, specifically when targeting a lower yield through an NPK+FYM mode. Thus, implementation of the STCR approach of fertilizer prescription, with or without FYM, at targeted yields of 25 and 22 t ha-1, not only surpassed the effects of the other fertilizer recommendation approach in terms of cob yields, but also increased NPK uptake, improved nutrient use efficiency and greater economic returns.