Promote Crop Growth Research Articles

Quantitative Evaluation of Post-Tillage Soil Structure Based on Close-Range Photogrammetry

Quantitative Evaluation of Post-Tillage Soil Structure Based on Close-Range Photogrammetry

Exogenous application of wood vinegar improves rice yield and quality by elevating photosynthetic efficiency and enhancing the accumulation of total soluble sugars

Rice is an important cereal crop for over half of the world population and essential for food security, especially in developing countries where it constitutes a substantial part of daily caloric intake. Wood vinegar, obtained from biomass pyrolysis and rich in organic acids, phenols, esters, sugars, and alcohols, promotes crop growth and productivity. Its diverse composition offers an eco-friendly and cost-effective growth promoter and improves stress tolerance in different crops; however, its optimal application timings in rice cultivation remain underexplored. Our study investigated the effects of wood vinegar on rice growth, photosynthetic efficiency, chlorophyll contents, soluble sugars, phenolics, grain chalkiness, and yield at different stages and combinations such as tillering (T), jointing (J), flowering (F), grain filling (G), T + J, T + F, T + G, J + F, J + G, F + G, T + J + F, T + J + G, T + F + G, and J + F + G. Our results indicate that wood vinegar application at T + J + F stages significantly enhanced the photosynthetic rate by promoting gaseous exchange, chlorophyll contents, and SPAD index when compared with control. Additionally, total soluble sugars (9.71 mg g−1) and phenolics (2.4 mg g−1) levels were noticeably induced during wood vinegar application as compared with corresponding control. Besides, this treatment also elevated the yield by up to 32.4%, reduced grain chalkiness, and enhanced head rice percentage. Taken together, these findings suggest that wood vinegar supports sustainable agriculture by improving crop yield and quality, offering considerable benefits to farmers.

Responses of Hybrid Rice (Oryza sativa L.) Plants to Different Application Modes of Nanosized Selenium.

The application of selenium (Se) fertilizer not only promotes crop growth but also meets the human demand for Se by increasing the Se content in food. However, the application of nanosized selenium (nano-Se) in hybrid rice (Oryza sativa L.) production has not been reported. Therefore, the present study conducted a field experiment to investigate hybrid rice's performance under the different application modes of nano-Se. The nano-Se solution was foliar-applied: once at the end of the tillering (S1), heading (S2), and grain-filling (S3) stages or twice at the end of the tillering stage and the heading stage (S4), and at the end of the tillering stage and the grain-filling stage (S5). The treatment without Se application was taken as the control (CK). The results showed that compared with CK, the S1, S2, S3, S4, and S5 treatments increased the grain yield by 27.83-40.60%, 16.06-25.95%, 14.78-40.86%, 20.94-43.79%, and 22.41-43.52%, respectively. The highest or equally highest grain yield was recorded in the S1 treatment. Yield-related traits including the effective panicle number, grain number per panicle, seed-setting rate, and 1000-grain weight significantly increased under nano-Se treatments. Compared with CK, nano-Se treatment increased the SPAD value (chlorophyll content), net photosynthetic rate, and dry matter accumulation by 3.82-32.83%, 2.85-59.55%, and 8.09-55.29%, respectively. An 11.51-572.85% higher grain Se content was recorded in nano-Se treatments than CK. Moreover, nano-Se application significantly enhanced the activity of superoxide dismutase and catalase. In conclusion, the foliar application of nano-Se enhanced the growth and yield formation of hybrid rice plants, and the S1 treatment was considered as the best application due to having the highest yield.

Impact of Bacillus Inoculation on Rhizosphere Bacterial Community Structure: A Review

The rhizosphere is a specialized zone where plant roots interact with the soil microbiome. Among various beneficial microbes, the genus Bacillus stands out due to its diverse functionalities and potential to boost plant growth and resilience. Bacillus is a key genus of plant growth-promoting rhizobacteria (PGPR) known for enhancing nutrient availability, producing phytohormones, and inducing plant resistance to pathogens. Inoculating Bacillus species into the rhizosphere can significantly alter the bacterial community's structure and composition. These alterations are driven by the competitive and cooperative interactions between Bacillus and the native rhizosphere microorganisms. Incorporating soil microorganisms into the host plant's beneficial bacterial community improves soil nutrient cycling and nutrient use efficiency. Using microbial inoculants is an effective strategy to address crop succession challenges, enhance microbial community structure, and improve soil fertility, thereby promoting crop growth. This review thoroughly examines the current understanding of how Bacillus inoculation impacts rhizosphere bacterial community structure.

Efficient resource recovery from food waste digestate via hydrothermal treatment and its application as organic fertilizer

With the continuous recognition of green, organic and non-polluting products, organic fertilizers play an increasingly vital role in agricultural production. Among them, hydrochar-based organic fertilizer has attracted widespread attention recently. The present study evaluated the potential of digestate from anaerobic digestion of food waste for the preparation of hydrochar-based organic fertilizer by straw-based, FeCl3-catalyzed hydrothermal carbonization (HTC). Under the optimal conditions, a hydrochar-based organic fertilizer with > 25 wt% humus content and limited pollution risk was successfully prepared. The pot experiment demonstrated the feasibility of improving the physicochemical properties of red soil and promoting crop growth after adding hydrochar in place of commercial fertilizer. In addition, the function of zeolite on nutrient recovery in hydrothermal liquid (HTL) was analyzed, and preparing the slow-release organic fertilizer by mixing the nutrient-rich zeolite with hydrochar in a mass ratio of 1:4 was proposed. This work has significant implications for achieving the efficient resource recovery of digestate.

Effects of Applying Organic Amendments on Soil Aggregate Structure and Tomato Yield in Facility Agriculture.

Amendment significantly improves soil structure and promotes crop growth. To combat soil degradation and low crop yields in facility agriculture, it is crucial to study the optimal application rate of amendments. This study analyzed the effects of biochar, vermicompost, and mineral-source potassium fulvic acid on the stability of aggregate structure, soil nutrient content, and tomato yield in cambisols, providing a theoretical basis for improving the soil quality of plastic greenhouses in Southern China. A pot experiment on tomato cultivation was carried out in yellow-brown soil in plastic greenhouses. The experiment included eight treatments: 1% biochar (B1); 3% biochar (B3); 5% biochar (B5); 3% vermicompost (V3); 5% vermicompost (V5); 0.1% mineral-source potassium fulvic acid (F1); 0.2% mineral-source potassium fulvic acid (F2); and the control condition without adding soil amendments (CK). The results showed that the biochar and vermicompost treatments effectively reduced soil bulk density and increased total soil porosity. Compared to the control, treatments with soil amendments significantly increased soil pH and had different effects on soil nutrients: F2 showed the most significant improvement in the content of available nitrogen, available phosphorus, and available potassium, with an increase of 133.33%, 834.59%, and 74.34%, respectively; B3 treatment had the highest increase in dissolved organic carbon (DOC), while B5 treatment had the highest organic matter content. Compared to the CK, the particle size of the biochar treatment was mainly 0.053~0.25 mm, while the V3, F1, and F2 mainly occurred with a particle size > 0.25 mm; and V3 has the best aggregate stability. Biochar, vermicompost, and mineral potassium fulvic acid can all promote tomato yield, with the F2 and V3 treatments having a yield increase effect of over 30%. Furthermore, Pearson's correlation analysis showed a highly significant positive correlation between geometric mean diameter (GMD) and mean weight diameter (MWD), water-stable macroaggregate content (R0.25), and a positive correlation between alkaline-dissolved nitrogen, available phosphorus, dissolved organic carbon content, and aggregate stability indicators. Adding 0.2% mineral-source potassium fulvic acid optimizes cambisols' properties, enhances aggregate formation and stability, boosts tomato yield, and shows great application potential.

Effects of nano-MoO3 on growth, quality and toxicity of soybean.

Metal nanoparticles are widely used in agricultural production. As a new type of molybdenum fertilizer, MoO3NPs have the properties of nanomaterials and the characteristics of molybdenum nutrition. Previous studies have focused on their role in promoting crop growth. However, it is unknown whether excessive MoO3NPs will affect crop quality and nutritional value. In this study, the effects of different concentrations of MoO3NPs (0, 0.15, 0.5, 1.0, 5.0, 10, 50, 100 mg kg-1) on the growth and quality of soybean were investigated by pot experiments to analyze the plant effects caused by MoO3NPs. The results showed that the effects of MoO3NPs treatment on plant biomass and nodule number were promoted at low concentrations (0.15-5 mg kg-1) and inhibited at high concentrations (10-100 mg kg-1). According to the logistic distribution model, it was predicted that MoO3NPs would have the strongest toxic effect on soybean flowering stage. The contents of MoO3NPs which reduced the yield of soybean by 10% and 20% were 12.38 and 30.81 mg kg-1. NP0.15 could significantly improve the total amount of amino acids in grains, while NP100 reduced the total amount of amino acids in grains, both of them significantly increasing the contents of linolenic acid and linoleic acid in soybean seeds. A change of MoO3NPs concentration had no negative effect on the nutritional value of soybean grains. The research could lead to a better understanding of the potential impact of nutritional changes caused by MoO3NPs on human health. © 2024 Society of Chemical Industry.

Preparation of agriculture film from cow manure for silage maize planting: Experimental study and life cycle assessment

With the development of modern breeding technology, the scale of dairy farming is becoming increasingly large, which leading to decoupling of planting and breeding. Hence, massive amounts of manure could not handled by traditional method in time, which caused serious environmental problems. Therefor, there is a urgent needs for industrialized treatment methods to treat cow manure for dairy farm industry. In order to expand the types of industrial treatment methods of cow manure, two types of industrialized cow manure based agriculture films were introduced in this research, manure slurry film (MSF) and manure paper film (MPF). Taking silage corn cultivation as an example, their feasibility were testified: the usage performances of the films were expanded by crop yield and soil physicochemical properties, and environmental impacts of the films was conducted by life cycle assessment (LCA). The results showed: (1) both MSF and MPF would decomposed in one growth period of silage maize, with MPF having better performance in temperature retention; (2) both MSF and MPF improved soil nutrients and agglomerate structures; (3) the yield of maize with MSF and MPF was increased from 62.6 t to 88.4 t and 84.6 t per hectare compared to control group; and (4) according to LCA, MPF had 39 % and 50 % lower average environment impact than PE film and MSF. In conclusion, manure based films could effectively promotes crop growth with lower environment impact compared with traditional methods, which thus might provide effective linkage strategies for coupling of planting and breeding.

Effect of Plow Pan on the Redistribution Dynamics of Water and Nutrient Transport in Soils

Plow pans are an essential part of the agricultural soil structure. By adjusting the soil bulk density and plow pan height, the water and nutrient transport are dynamically redistributed. Plow pans play a crucial role in promoting crop growth, increasing yields, and supporting sustainable land management. In this study, a column experiment was conducted to investigate the effects of plow pan height (10 cm and 15 cm) and bulk density (1.2, 1.4, and 1.6 g cm⁻3) on soil nutrient and water leaching under high-volume (HV) and low-volume (LV) fertilizer applications. The results reveal that the leachate volume decreased by 61.9% at a plow pan height of 10 cm and by 96.2% at a plow pan height of 15 cm when the bulk density was increased from 1.2 to 1.4 g cm⁻3 under HV conditions. There was no leachate when the plow pan bulk density was 1.6 g cm−3. The reserved concentration of alkali-hydrolyzable N in the plow pan soils was the highest when the plow pan had a bulk density of 1.4 g cm−3 and a height of 15 cm. However, when the plow pan height was 15 cm, the available P content in the plow pan soils decreased by 27.0% and 21.0% at bulk densities of 1.4 g cm⁻3 and 1.6 g cm⁻3, respectively, when compared with 1.2 g cm⁻3. Furthermore, the available P concentrations in the plow pan and subsoil layers decreased with an increase in the plow pan height. The available K concentrations in the topsoil decreased by 26.8% and 24.0% when the plow pan bulk density was increased from 1.2 to 1.4 g cm−3 at heights of 10 and 15 cm, respectively. Thus, the optimal plow pan height and bulk density are closely related to the types of soil nutrients. However, it is clear that excessively high bulk densities (e.g., 1.6 g cm−3) negatively impact soil properties. For different nutrient requirements, a bulk density of 1.2 or 1.4 g cm−3 can be chosen, with each providing suitable options based on the specific nutrient needs. This research offers practical insights into changes in nutrient adsorption and fixation in agricultural production associated with alterations in plow pan bulk density.

The Impact of Exogenous Sodium Selenite Treatment on the Nutritional Value and Active Constituents of Pueraria lobata

Moderate amounts of Se can promote crop growth, enhance stress resistance, increase yield, and improve nutritional quality. In the present study, kudzu seedlings were used as experimental materials, and their physiological indicators, antioxidant activity, nutritional components, and flavonoid content were measured after being treated with Na2SeO3 hydroponics. Transcriptome sequencing analysis was used to reveal the relevant genes involved in regulating the effects of exogenous Se on the content of Se-compounds and flavonoids in kudzu. The results indicated that treatment with 20 mg/L Na2SeO3 significantly increased stem and root lengths, dry and fresh weight, lateral root development, and chlorophyll b content. However, at higher concentrations (30–40 mg/L), lateral root abundance and chlorophyll levels decreased. Na2SeO3 treatment also augmented the antioxidant capacity and enhanced the content of major nutrients in kudzu seedlings. The total Se content in kudzu escalated with increasing Na2SeO3 concentration, with selenomethionine emerging as the primary organic-Se species. After treatment with Na2SeO3, the content of puerarin in both aboveground and underground parts decreased, while the content of total flavonoids increased. Daidzin increased in the roots. Differential expression gene analysis revealed that genes such as TRXB2, SYM, MMT1, and METE were involved in Se uptake and transformation in kudzu, while bZIP43 and WRKY47 played a role in flavonoid biosynthesis.

Intercropping of tobacco and maize at seedling stage promotes crop growth through manipulating rhizosphere microenvironment.

Changes in the rhizosphere microbiome and metabolites resulting from crop intercropping can significantly enhance crop growth. While there has been an increasing number of studies on various crop combinations, research on the intercropping of tobacco and maize at seedling stage remains limited. This study is the first to explore rhizosphere effects of intercropping between tobacco and maize seedling stages, we analyzed the nitrogen, phosphorus and potassium nutrients in the soil, and revealed the important effects on soil microbial community composition and metabolite profiles, thereby regulating crop growth and improving soil balance. Compared with mono-cropping, intercropping increased the biomass of the two crops and promoted the nutrient absorption of nitrogen, phosphorus and potassium. Under intercropping conditions, the activities of sucrase, catalase and nitrate reductase in tobacco rhizosphere soil and the content of available potassium, the activities of nitrate reductase and acid phosphatase in maize rhizosphere soil were significantly increasing. Rhizosphere soil bacterial and fungal communities such as Sphingomonas, Massilia, Humicola and Penicillium respond differently to crop planting patterns, and soil dominant microbial communities are regulated by environmental factors such as pH, Organic Matter, Available Potassium, Nitrate Reductase, and Urease Enzyme. Network analysis showed that soil microbial communities were more complex after intercropping, and the reciprocal relationship between bacteria and fungi was enhanced. The difference of metabolites in soil between intercropping and monocropping system was mainly concentrated in galactose metabolism, starch and sucrose metabolism pathway, and the content of carbohydrate metabolites was significantly higher than that of monocropping soil. Key metabolites such as D-Sucrose, D-Fructose-6-Phosphate, D-Glucose-1-Phosphatel significantly influence the composition of dominant microbial communities such as Sphingomonas and Penicillium. This study explained the effects of intercropping between flue-cured tobacco and maize on the content of soil metabolites and soil microbial composition in rhizosphere soil, and deepened the understanding that intercropping system can improve the growth of flue-cured crops seedlings through rhizosphere effects.

Mitigation of salinity stress on morpho-physiological and yield related parameters of rice using different organic amendments

Salinity is a pernicious abiotic element that hinders crop development. Utilizing organic amendments to remediate salt is crucial for enhancing soil function and promoting crop growth. Based on this, a pot experiment was carried out at the research field of Khulna Agricultural University, Khulna, to examine the physiology, growth, and yield of transplanted aman rice in response to salinity stress using duckweed, and dhaincha biomass supplement. Excess salinity with no organic amendments reduced plant growth and development, relative water content (26%), and membrane stability (28%), index compared to T1 S1 (duckweed), and T2 S1 (dhaincha) at 50 mM salinity. Salinity delayed the emergence of first flowering and the maturity of filled grains. The lowest grain yield was recorded in T0S3 (no treatment + 100 mM salinity). Application of dhaincha and duckweed biomass ameliorates salinity individually at all salinity levels. Rice grown in saline soil with the application of T1 (duckweed biomass) and T2 (Sesbania biomass) had an 87% spikelet fertility while rice grown in soil without T1 and T2 treatment had only 21.82%. The application of T2 and T1 @ 5 t ha-1 increased grain yield by 33.29% and 4.70% compared to control. Furthermore, salinity stress @100 mM NaCl with duckweed decreased grain yield by 0.05% which was minimized to 12% by applying dhaincha green manure (T2) @ 5 t ha1. The finding showed that the ameliorative impact of green manure at 5 tha1 dose (T2) was more effective compared to the duckweed (T1) at the three salinity levels used in the study.

Using Bone Char as a Renewable Resource of Phosphate Fertilizers in Sustainable Agriculture and its Effects on Phosphorus Transformations and Remediation of Contaminated Soils as well as the Growth of Plants

AbstractRecycling slaughterhouse waste such as bone and converting it into bone char is a promising environmentally friendly, low-cost strategy in a circular economy and an important source of phosphorus. Therefore, this review focused on the impacts of bone char on the availability, dynamics, and transformations of phosphorus in soils as well as plant growth and utilizing bone char in remediating contaminated soils by heavy metals. Bone char is material produced through bone pyrolysis under limited oxygen at 300–1050 °C. Bone char applications to the soils significantly increased phosphorus availability and plant growth. Agricultural practices such as co-applying organic acids or sulfur or nitrogen fertilizers with bone char in some soils played an important role in enhanced phosphorus availability. Also, co-applying bone char with phosphate-solubilizing microorganisms enhanced plant growth and phosphorus availability in the soils. Applying bone char to the soils changed the dynamics and redistribution of phosphorous fractions, enhanced fertility, promoted crop growth and productivity, reduced heavy metals uptake by plants in contaminated soil, and decreased heavy metals bioavailability. Bone char has shown positive performance in remediating soils contaminated by heavy metals. Bone char proved its efficiency in sustainable agriculture and practical applications as an alternative source of phosphate fertilizers, it is safe, cheap and helps in remediating contaminated soils by heavy metals. Using bone char as a slow-release fertilizer is potentially beneficial because it reduces the hazard of excessive fertilizing and nutrient leaching which have negative impacts on the ecosystem.

Potassium supply for improvement of cereals growth under drought: A review

AbstractPotassium (K) is an essential macronutrient that determines crop productivity and promotes crop growth under conditions of abiotic stress. In this review paper, peer‐reviewed publications (experimental data) dealing with the role of K administration in the control of cereals growth under drought stress are reviewed and analyzed. Most published research on the impact of K administration on cereals growth under drought focuses primarily on bread wheat (Triticum aestivum L.) and maize (Zea mays L.), along with barley (Hordeum vulgare L.), rice (Oryza sativa L.), pearl millet (Pennisetum glaucum L.), and sorghum (Sorghum bicolor L.). The beneficial effect of K on cereals growth under drought has been related to maintenance of water balance in the crops, increased activity of the antioxidant enzymes, increased synthesis of osmolytes, contribution to a low sodium (Na)/K ratio, extension of the grain filling period, and increase of the grain growth rate and weight. Moreover, K was suggested as a possible way for enhancing nitrogen use efficiency (e.g., bread wheat and sorghum). Nevertheless, the beneficial effect of foliar applied K in dried soil during grain filling differed among bread wheat cultivars, highlighting that the effect of K supply on grain weight may differ depending on application method, that is, administration through the soil or the foliage. Overall, K supply could be exploited as a tool for increasing cereal tolerance to drought, for example, by considering late administration of K through top dressing applications or foliar sprayings. Yet additional information is needed on the rate and the K form, along with the most suitable growth stage for application. Such information could help agronomists develop strategies for high‐quality cereal production in stressful environments.

Research Progress and Trend of Biochar based Microbial Fertilizer

Biochar based microbial fertilizer has loose porous structure, which can improve soil structure, improve soil fertility, promote crop growth, and provide strong support for agricultural sustainable development. In this paper, the research progress of biochar based microbial fertilizer in the preparation process, fertilizer efficiency research, application effect and other aspects was reviewed, and it was pointed out that in the future, in-depth research should be carried out in the aspects of preparation process and performance optimization, microbial strain screening and function enhancement, application effect and mechanism research, standardization and standardization system establishment, application field expansion and technology innovation.

Biochar and wood vinegar altered the composition of inorganic phosphorus bacteria community in saline-alkali soils and promoted the bioavailability of phosphorus

As an important part of the ecosystem, saline-alkali soils are in urgent need of efficient and environmentally friendly soil conditioners. Biochar and wood vinegar are regarded as organic soil improvement and plant growth regulators to improve soil physicochemical properties and promote crop growth. However, the mechanism of how inorganic phosphorus bacteria increase phosphorus when biochar and wood vinegar applied to saline-alkali soils is not clear. Herein, the present study was designed to investigate the effects of biochar and wood vinegar with different rates on physicochemical properties of saline-alkali soils and inorganic phosphorus bacteria diversities and to discuss the mechanism of biochar and wood vinegar on available phosphorus by pot experiments. The application of biochar and wood vinegar exhibited an effect on the decrease in pH and salt contents and the increase in soil porosity, soil nutrients, and hundred-grain weight of rice. The 600 kg ha−1 biochar and 1800 kg ha−1 wood vinegar group showed the most significant increment in available phosphorus, alkaline phosphatase, acid phosphatase, and neutral phosphatase activities, with the increases of 49.24%, 40.35%, 48%, and 149%, respectively. The 600 kg ha−1 biochar and 1200 kg ha−1 wood vinegar group significantly enhanced microbial biomass phosphorus concentrations by 41.29%. Moreover, biochar and wood vinegar shifted inorganic phosphorus bacteria composition structure and promoted its diversities, more so at a higher rate of wood vinegar application. The dominant species of inorganic phosphorus bacteria were Proteobacteria, Gammaproteobacteria, Alphaproteobacteria, Pseudomonas, and Rhizobium in saline-alkali soils. The Alphaproteobacteria and Hydrogenophaga were the key microorganisms reducing pH and salt contents and increasing available phosphorus contents in saline-alkali soils. In conclusion, the application of biochar and wood vinegar was a useful strategy to improve saline-alkali soils.

Bacillus cereus CGMCC 1.60196: a promising bacterial inoculant isolated from biological soil crusts for maize growth enhancement.

Soil microbial inoculants are widely recognized as an environmentally friendly strategy for promoting crop growth and increasing productivity. However, research on utilizing the microbial resources from desert biological soil crusts to enhance crop growth remains relatively unexplored. In the present work, a bacterial strain designated AC1-8 with high levels of amylase, protease, and cellulase activity was isolated from cyanobacterial crusts of the Tengger Desert and identified as Bacillus cereus (CGMCC 1.60196). The refinement of the fermentation parameters of B. cereus CGMCC 1.60196 determined that the most effective medium for biomass production was composed of 5 g/L glucose, 22 g/L yeast extract and 15 g/L MgSO4, and the optimal culture conditions were pH 6.0, temperature 37°C, inoculation quantity 3% and agitation speed 240 rpm. Furthermore, the utilization of B. cereus CGMCC 1.60196 has resulted in substantial improvements in various growth parameters of maize seedlings, including shoot length, shoot fresh and dry weights, root fresh and dry weights, and the contents of chlorophyll a, chlorophyll b, and total chlorophyll. The most pronounced growth promotion was observed at an application concentration of 1 × 109 CFU/m2. These results suggest that the novel B. cereus strain, isolated from cyanobacterial crusts, can be regarded as an exemplary biological agent for soil improvement, capable of enhancing soil conditions, promoting crop cultivation and supporting food production.

Effects of Bacillus subtilis on cotton physiology and growth under water and salt stress

The scarcity of fresh water resources has severely limited agricultural production in arid areas. Although brackish water irrigation or fresh water deficit irrigation can alleviate the water resources crisis, both may cause water and salt stress to crop. Therefore, this study is based on the functional advantages of Bacillus subtilis in soil improvement and crop growth promotion to alleviate water and salt stress and build safe and efficient water-saving irrigation patterns. In this study, cotton (No. 50 Chuangmian) was selected as the research crop, and five application rates of Bacillus subtilis (0, 22.5, 45, 67.5 and 90 kg·ha−1) were combined with three irrigation patterns (brackish water, fresh water and fresh water deficit irrigations) to study the effects of Bacillus subtilis on soil moisture and salinity, soil microbial community, cotton physiology and growth under water and salt stress. The results showed that Bacillus subtilis could enhance soil water retention capacity, promote soil desalination, improve cotton growth indices (plant height, stem diameter, leaf area index, dry matter accumulation), and then increase yield and water use efficiency (WUE). Compared with the control treatment, the yield and WUE of Bacillus subtilis application treatments increased by 3.32–54.67 % and 1.68–41.07 %, respectively. In the cotton physiology characteristics, Bacillus subtilis increased proline content and the activity of superoxide dismutase, peroxidase and catalase while decreased malondialdehyde content in cotton leaves. Bacillus subtilis could enhance the relative abundance of bacteria with the functions of nitrogen fixation, stress resistance and biocontrol. A structural equation model proved that Bacillus subtilis could improve yield and WUE indirectly by directly improving soil microbial diversity, alleviating water and salt stress, and then improving cotton physiology and growth. According to a comprehensive evaluation of cotton physiology and growth, it was determined that the optimal improvement effect was achieved when the application rate of Bacillus subtilis was 45 kg ha−1; the synergistic effect of brackish water irrigation and Bacillus subtilis (45 kg·ha−1) was superior to that of fresh water deficit irrigation combining with Bacillus subtilis (45 kg·ha−1), which could be considered a priority strategy for alleviating the fresh water crisis in arid areas and promoting the efficient increase in cotton yield.

Intercropping wheat and appropriate nitrogen supply can alleviate faba bean wilt disease by reshaping soil microbial community structure

RationaleThe faba bean-wheat intercropping system is widely adopted to mitigate the incidence of faba bean wilt. The application of nitrogen fertilizers is imperative for promoting crop growth. Determining the optimal nitrogen dosage is crucial for enhancing the disease control efficacy of intercropping systems. So far, the impact of different nitrogen input management on soil microbial communities during the occurrence of faba bean diseases under intercropping conditions of faba bean and wheat has not been clear. ObjectiveTo explore the effect of different nitrogen application levels on the inter-root soil microbial community of faba bean in intercropping scenarios and its relationship with the incidence of faba bean wilt. Materials and methodsTwo planting modes, namely sole faba bean cultivation (M) and faba bean-wheat intercropping (I), were established in both field and pot experiments. Four nitrogen application levels (N0: 0 kg ha−1; N1: 45 kg ha−1; N2: 90 kg ha−1; and N3: 135 kg ha−1) were used to assess the incidence of wilt disease in faba bean. Furthermore, collect soil samples from the rhizosphere of faba bean plants for enzyme and microbial assays in the rhizosphere soil. ResultsThe application of nitrogen (N1, N2, and N3) reduced the incidence of faba bean wilt in the monocultures. Among the same N application levels, intercropping exhibited a significant decrease in wilt incidence compared with monocropping, with the lowest incidence observed at the N2 level. Additionally, the rhizosphere enzyme activity in faba bean was maximized under intercropping at the N2 level. Intercropping increased the richness and diversity of soil microorganisms, leading to an adjusted microbial community structure and the promotion of beneficial microorganism functions. Notably, nitrogen application played a pivotal role in changing the rhizosphere soil microbial community structure of faba bean. A reasonable nitrogen application rate (N2) can significantly improve the disease control effects of intercropping. ConclusionIntercropping with N2(90 kg ha−1) resulted in a significant increase in microbial diversity in faba bean soil. This led to an adaptable microbial structure, effectively mitigating the occurrence of faba bean wilt and ultimately promoting soil function and health.

Effect of Streptomyces costaricanus Strain A-m1 as a Bioinoculant on Tea Garden Soil and Tea Quality

Chemical fertilization is usually associated with some unreasonable problems that affect the sustainable production of tea gardens. The micro-organism fertilizer created from plant growth-promoting microbes (PGPM) integrates the beneficial properties of functional micro-organisms and bioinoculants. Application of PGPM can activate soil nutrients, prevent soil-borne diseases, and promote crop growth, thus improving crop quality and yield. In this study, the effects of bioinoculants composed of Streptomyces costaricanus strain A-m1 on the properties, enzyme activity, and micro-organisms of soil in a tea garden and on the chemical composition and production of tea were investigated. The present results showed that the application of A-m1 bioinoculant could increase the activities of urease, protease and catalase, the content of alkali-hydrolyzable nitrogen, and the number of bacteria, fungi, and actinomycetes in tea garden soil. After application, the free amino acid content, 100-bud weight, and bud density of spring tea were also elevated. In the year of fertilization, the treatment composed of 70% bioinoculant + 30% chemical fertilizer showed the best effects on soil physical and chemical properties, enzyme activity, culturable microbial counts, and tea quality. A high ratio of organic to chemical fertilizer coapplication can significantly improve the growing conditions for tea plants, reduce the use of chemical fertilizers, improve the efficiency of nutrient utilization, and enhance both the yield and quality of tea. One year after fertilization, the 50% bioinoculant + 50% chemical fertilizer was more conducive to enhancing the quality of tea, while the 30% bioinoculant + 70% chemical fertilizer was more beneficial for improving the production of tea. A high ratio of chemical to bioinoculant coapplication is more favorable for maintaining high yield and quality in tea production, achieving healthy and sustainable tea garden management. The application of A-m1 bioinoculant will reduce the use of chemical fertilizers, improve the utilization efficiency of soil nutrients, and increase the production and quality of tea, contributing to the sustainable production of tea gardens.