Effect of lactic acid bacteria inoculants on alfalfa(Medicago sativa L.) silage quality:assessment of degradation(in situ) and gas production(in vitro)

Alfalfa （Medicago sativa） is difficult to ensile successfully because of the low content of moisture and water-soluble carbohydrates （WSC） in fresh alfalfa and the high buffering capacity in fresh alfalfa. Here, we conducted a study to evaluate the effects of three lactic acid bacteria （LAB） inoculants （Lactobacillus case/, lactobacillus plantarum, and Pediococcus pentosaceus） on silage quality, in sitE/ruminal degradability, and in vitro fermentation of alfalfa silage. The first cut of alfalfa was wilted, chopped, and randomly divided into four groups： the control （CON） and control mixed with three separate LAB inoculants （106 cfu g-1）. Simmental steers with a body weight of （452±18） kg and with installed rumen fistulas were prepared for in situ degradation and for in vitro gas production. LAB inoculants had a lower （P〈0.05） content of butyric acid than the CON group. Among them, the L. casei inoculated silage had a higher （P〈0.05） content of water-soluble carbohydrate （WSC） and a lower （P〈0.05） NH3-H content. The effective degradation （ED） of crude protein in LAB inoculation decreased （P〈0.05）, while the ED of acid detergent fiber increased （P〈0.05） in situ fermentation. The alfalfa silage with LAB inoculants produced more carbon dioxide （P〈0.05）. The NH3-H content of mixed incubation fluid in L. casei inoculated silage was lower （P〈0.05） compared with other groups. Therefore, this study showed that LAB inoculants could improve both ensiling quality and degradation. In particular, the L. casei inoculations exhibited better performance by limiting proteolysis during ensiling.

Improving Acacia auriculiformis seedlings using microbial inoculant(Beneficial Microorganisms)

A microbial inoculant, known as effective microorganisms （EM）, was applied to determine its efficacy on seed germination and seedling growth in the nursery of Acacia auriculiformis A Curm. ex Benth. The seedlings were grown in a mixture of sandy soil and cow dung （3：1） and kept in polybags; EM was poured at different concentra- tions （0.1%, 0.5%, 1%, 2%, 5% and 10%）. Seed germination rate and growth parameters of seedlings - shoot and root lengths, fresh and dry weights of shoots and roots, vigor, volume, and quality indices and stur- diness - were measured. The nodulation status influenced by EM was also observed, along with the measurement ofpigrnent contents in leaves. The highest germination rate （72%） was observed in 2% EM solution while the lowest （55%） was found in control treatment. The highest shoot and root lengths （30.6 cm and 31.2 cm respectively） were recorded in 2% EM and were significantly （p 〈0.05） different from control. Both fresh and dry weights of shoots were maximum （8.66 g and 2.99 g respectively） in 2% EM, whereas both fresh and dry weights of root were maximum （2.56 g and 1.23 g respectively） in 5% EM solution. Although the highest vigor index, volume index, and sturdiness （4450, 628 and 67.5 respec- tively） were found in 2% EM, the highest quality index （0.455） was found in 5% EM solution. The nodule number was higher at a very low （0.5%） concentration of EM but it normally decreased with the increase of concentration. The contents of chlorophyll a, chlorophyll b, and carotenoid were maximum （43.26 mg.L-1, 13.56 mg.L-1 and 17.99 mg.L-1 respectively） in 2% EM. Therefore, low concentration of EM （up to 2%）can be recommended for getting maximum seed germination and seed- ling development ofA. auriculiformis in the nursery.

The Effect of Microbial Inoculants Applied at Ensiling on Sorghum Silage Characteristics and Aerobic Stability

Whole crop forage sorghum (Saccharatum) cultivar FS5 was harvested at the soft dough stage of maturity. The sorghum was chopped to approximately 2 cm pieces and ensiled under laboratory conditions in 1.5 L Weck glass jars. At ensiling, it was treated with two commercial microbial inoculants: inoculant A and inoculant B. The inoculants were applied at 2 × 105 colony forming units g-1 DM. Silage with no additives served as a control. Three jars per treatment were opened on days 2, 4, 8, 15 and 60 post-ensiling to study fermentation dynamics. After 60 days of ensiling, the silages were analyzed and subjected to an aerobic stability test lasting 5 days. Results showed that both inoculants caused a more rapid rate of pH decline and a higher amount of lactic acid production. Silages treated with each inoculant produced a little more CO2 and resulted in more glucose loss as compared with the control. Addition of inoculants did not influence (P > 0.05) the ash and crude protein contents, but tended to decrease the concentration of acetic acid (P < 0.05), butyric acid (P<0.01) and propionic acid (P<0.01), and increase the lactic acid concentration (P<0.01). Silages treated with inoculant A possess the more DM loss, and the higher yeast counts upon aerobic exposure. Silage treated with inoculant B had the most DM (P<0.05), lactic acid contents (P<0.01), the least acetic acid content (P<0.05). Inoculant B reduced the ADF (P<0.01), ADL and NDF (P<0.05) contents. It was concluded that lactic bacteria inoculants may improve the fermentation but might impair the aerobic stability for sorghum ensilage.

Effects of Microbial Inoculants on Nutrient Availability and Rice Yield

Under field conditions, an experiment was conducted to study the effects of ammonification bacteria, potassium bacteria and phosphorus bacteria on nutrient availability in soil and yield of rice in the cold region of China and compared to the conventional fertilization. Results showed that DF1P2 treatment （ammonifiers 1.5× 108 cfu· m2, phosphorus bacteria 1.5× 108 cfu. m2, and potassium bacteria 1.5× 108 cfu· m2） increased available nutrient concentrations in soil, increased the concentrations of N, P, and K in plant organs and increased the rice yield and was the most significantly among all the treatments. This treatment could be recommended as the best suitable biological fertilizer application rate for the rice production in the cold region of China.

Application of complex inoculants in improving the processability of grey cast iron for cylinder blocks

Effect of several complex inoculants on mechanical properties, process-ability and sensibility of grey cast iron used in cylinder block were investigated. The experimental results showed that the grey cast iron treated with 60%FeSi75+40%RE complex inoculants has tensile strength consistently at about 295 MPa along with good hardness and improved metallurgy quality. While the grey cast iron inoculated with 20%FeSi75+80%Sr compound inoculants has the best process-ability, the lowest cross-section sensibility and the least microhardness difference. The wear amount of the drill increases correspondingly with the increase of the microhardness difference of matrix structure, indicating the great effect of homogeneousness of matrix structure in the grey cast iron on the machinability of the grey cast iron.

Effect of Lactic Acid Bacterial Inoculants on Rice Straw Silage

The trail was designed to study on technique aspects of ensiling rice straw （RS） appended amounts of lactobacillus. There were two groups according to silage ways, baled silage （BS） and chopped silage （CS）, in which lactobacillus was added at levels of 10, 15 and 20 mg·kg^-1, respectively and the mixtures were placed into a packed polyethylene bags and stored at room temperature for 45 days. The results showed that lactobacillus had remarkable effect on fermentation characteristics of RS. The quality of the silage was improved with the lactobacillus addition. In the experiment the optimal quality of rice straw silage （RSS） can be obtained when lactobacillus was added with 15 or 20 mg·kg^-1 level. The effect of different silage methods was very remarkable to the silage quality of same material. The quality of CS was better than that of long silage, at the same time, BS was feasible on condition of eligible level of lactic acid bacteria.

Nursery practice on seed germination and seedling growth of Dalbergia sissoo using beneficial microbial inoculants

Nursery practice using microbial inoculants was performed to find out the efficacy of the inoculants on seed germination and seedling growth of sissoo（Dalbergia sissoo Roxb.）.Microbial inoculants or effective microorganisms（EM） are a mixture of many different beneficial microorganisms in a solution.The seedlings were grown in a mixture of sandy soil and cowdung（3：1） kept in polybags with pouring EM solution at different concentrations（0.1%,0.5%,1%,2%,5% and 10%） before and after a week of sowing the seeds.Seed germination rate and growth parameters of seedlings were measured,such as,shoot and root length,vigor index,fresh and dry weight of shoot and root and total biomass increment.The nodulation status influenced by EM was also observed along with the measurement of pigment contents in leaves.The highest germination rate（69%） was observed in 2% EM treatment,followed by 67% and 65% in 1% and 5% EM.The highest shoot length（33.2 cm） was in 2% EM,whereas highest root length（26.3 cm） was in 1% EM.Both fresh and dry weights from shoot and root,were maximum（4.16 g and 1.57 g;2.12 g and 0.83 g respectively） in 2% EM and were significantly（p ≤ 0.05） different from control.Vigor index was highest（4071） in 2% EM,which was significantly（p ≤ 0.05） different from control.Total dry weight increment was highest in 2% EM treatment,followed by 1% and 5% concentrations of EM.Nodulation number was higher at very low（0.1%） concentration of EM solution but it normally decreased with the increase of EM concentrations.The contents of chlorophyll a,chlorophyll b and carotenoid were highest（60.11,17.05 and 42.48 mg·L1respectively） in 2% EM treatment and lowest（39.35,13.55 and 27.29 mg·L-1 respectively） in control treatment.Therefore,low concentration of EM（up to 2%） can be used for getting maximum seed germination rate and seedling development of Dalbergia sissoo Roxb.

Biochar Based Inoculants Improve Soybean Growth and Nodulation

Most rhizobial inoculants that stimulate legume yield are applied with carriers that enhance root contact. The physicochemical properties of biochar are suitable for microbial growth, and it could be an alternative to peat, which comes from decreasing reserves but is the commonest solid inoculant carrier. The aim of the current research was to evaluate biochars as carriers of bradyrhizobia in solid inoculant and as coatings for seeds. Biochars and peat were inoculated with Bradyrhizobium japonicum strain 532C and storage time was assessed. A seed coating system was developed using biochar, bacteria liquid culture, water, and guar gum. The viability of bacteria in the coating and in solid biochar was evaluated at 4°C and 21°C. Two biochars were selected for a germination assay. Finally, greenhouse experimentation investigated the effect of biochar inoculant and seed coating on soybean growth and nutrient uptake. The storage time experiment showed that not all biochars equally sustain bacteria survival over time. The germination assay demonstrated that biochar seed coating had no effect on soybean germination. Greenhouse experimentation indicated that the effect of Pyrovac biochar on soybean growth characteristics and nutrient uptake depended on the fertilizer. The main finding was that biochar solid inoculant positively affected plant growth metrics, root characteristics, and the chemical composition of plants supplied with N-free nutrient solution.

Effect of Morphology of Instantaneous Inoculant on Inoculated Result of Melted Iron

The characteristics of some elements in inoculant were analyzed.The effect of the morphology of instantaneous inoculant on its melting velocity was studied.When the inoculants pass through the same sieve number,the volume and the ratio of surface area to volume are different.It is evident from the theoretical analysis and experiment under some conditions that the melting velocity of inoculant depends on the morphology of inoculant.The morphology of inoculant during production should be controlled carefully.

Research Advances in Preparation of Arbuscular Mycorrhizal Fungi Inoculants

Arbuscular mycorrhizal fungi （AMF） can enhance plant stress resistance against biological and abiotic factors, playing an important role in increasing crop yield and reducing pesticide use. It is also of great development potential in agriculture, horticulture, forestry and environmental remediation. We summarized preparation of AMF inoculants from the components of inoculant preparation system, including mycorrhizal fungi, host plants, culture matrix and nutrition, and pointed out the direction and prospect of inoculants market in the future.

Effects of Microbial Inoculants from Sewage Sludge on Initial Growth of Festuca arundinacea L.

Microbial inoculants were isolated from sewage sludge and applied to turfgrass medium. Effects of microbial inoculants on seed germination and initial growth of Festuca arundinacea L. were analyzed to investigate the optimal proportion of compound microbial inoculants. Significant differences were found in various growth indices and chlorophyll content of F. arundinacea between microbial treatment and control The combination of Pseudomonas stutzeri and Trichoderma reesei exhibited the best results. Compared with the control, seed germination rate, seedling height, shoot dry weight, root weight, chlorophyll a content and chlorophyll b content of F. arundinacea treated with the combination of Pseudomonas stutzeri and Trichoderma reesei were improved by 11.60%, 43.47%, 148%, 159%, 144% and 136%, respectively. Based on comprehensive analysis of various indicators, the optimal proportion （V/V） of microbial combination was Pseudomonas stutzeri： Tfichoderma reesei = 1： 1, which was the most conducive to plant growth and development.

Research Progress of Application of Microbial Inoculants in Agricultural Production

Microbial inoculants have received increasing attention in strengthening plant biological barriers,antagonizing and inhibiting harmful microorganisms,and ensuring the safe production of agricultural products.This paper summarized the research status of agricultural microbial inoculants,the application of microbial inoculants in agriculture,and the trends and prospects of agricultural microbial research.

Effects of Low Temperature-tolerant Microbial Inoculants from Municipal Solid Waste Compost on Turf Storage in Winter

Beneficial microorganisms were extracted from municipal solid waste compost and treated under low temperature stress to prepare complex microbial inoc- ulants. Turfgrass was inoculated with the prepared microbial inoculants to investigate the ecological effect of ~crobial inoculants on turf storage in winter. The re- suits showed that complex low temperature tolerant microbial inoculants significandy improved plant height and aboveground biomass of turfgrass. Compared with the non-inoculated control, plant height and biomass of the first batch of inoculated turfgrass were enhanced by 6.47% and 14.32%, respectively; and they were en- hanced by 6.94% and 17.41%, respectively, for the second batch of inoculated turfgrass. Under low temperature stress in winter, the reviving rate of inoculated tarfgrass was significandy higher than that of control, which was improved by 3.34% and 43.33% for the first and second batches of inoculated turfgrass respective- ly. After low temperature storage in winter, inoculated turfgrass revived in advance; specifically, the reviving date of the second batch of inoculated turfgrass was 3 d earlier than that of control. This low temperature tolerant microbial consortium was effective for turfgrass as an ecofriendly and acceptable technology to improve plant performance and development in winter and accelerate time to market of turf.

Preparation of slow-release regulated Rs-198 bilayer microcapsules and application of its lyophilized bacterial inoculant on Capsicum annuum L.under salt stress

The survival adaptation of bacteria in saline soil is poor.The bilayer microcapsules were prepared by secondary embedding of monolayer sodium alginate(NaAlg)-bentonite(Bent)-sodium carboxy-methylcellulose(CMC)microcapsules wrapped with plant growth promoting rhizobacteria(PGPR)Pseudomonas putida Rs-198 by chitosan solution to promote the synergistic effect of bilayer microen-capsulation and PGPR.The characterization of the Rs-198 bilayer microcapsules showed that the amino and carboxyl groups were cross-linked and a thin layer of chitosan was formed on the outside of the microcapsule.The bilayer microcapsule(Ch-d)with a chitosan concentration of 0.8 wt%and pH 6 showed a slow release of bacteria with a maximum release of 6.06 × 10^(9) cfu/g on the 7th day.The viable bacteria of Ch-d increased by 4.42%after 60 days of storage compared with monolayer microcapsules.The 0.9 wt%L-cysteine,10 wt%glycerinum,10 wt%trehalose and 12 wt%soluble starch were added as bacterial protective agents during the process of preparing the Ch-d lyophilized bacterial inoculant(Ch-d LBI).Pot experiments showed that Ch-d LBI exhibited better growth promotion of Capsicum annuum L.under salt stress.Therefore,the bilayer microcapsule as slow-release bacterial inoculant is a potential alternative for sustainable agriculture.

Effects of compound microbial inoculant treated wastewater irrigation on soil nutrients and enzyme activities

Wastewater treated by compound microbial inoculant(CMI)in agricultural irrigation can enrich soil fertility and decompose the possible pollutants.In this study,a greenhouse experiment using tomato as the model crop was performed to investigate the effects of treated wastewater irrigation on soil nutrients and enzymes.For this purpose,certain parameters were measured,including soil total nitrogen(N),nitrate N,total phosphorus(P),available potassium(K)and the activities of the enzymes urease,acid phosphatase and catalase in soils irrigated with fresh water,wastewater and CMI-treated wastewater under three amount of irrigation water.The results showed that irrigation with both treated and untreated wastewater significantly increased soil total N,total P,and available K,however the treated wastewater showed higher effects on soil enrichment,especially on available K.The activity of soil urease and acid phosphatase reached highest with treated wastewater irrigation,whereas wastewater irrigation increased the activity of catalase obviously.Soil enzyme and nutrient with fresh water irrigation decreased with increasing water amount;the content of soil urease,nitrate-nitrogen,total N and total P in treated wastewater and wastewater irrigation rose with increasing water amount,but the highest activity of acid phosphatase and the lowest activity of catalase were found in medium irrigation water amount.Under the condition of tomato cultivation,total N,nitrate N and total P were closely correlated with soil urease and catalase;there were significant positive correlation among soil urease,catalase,total N,nitrate N and total P;there existed significantly positive correlation between acid phosphatase and all measured soil nutrient indexes.The results suggested that irrigation with CMI-treated wastewater is a security and effective strategy to agricultural land management.

Influence of rare earth nanoparticles and inoculants on performance and microstructure of high chromium cast iron

The high chromium cast irons （HCCIs） with rare earth （RE） nanoparticles or inoculants were fabricated in the casting process. The phase compositions and microstructure were analyzed by X-ray diffraction （XRD） and optical microscopy （OM）, respectively. The hardness and impact toughness were tested by Rockwel-hardmeter and impacting test enginery. And then, the morphology of fracture was researched by scanning electron microscopy （SEM）. The results demonstrated that the phase compositions of HCCIs with addition of RE nanoparticles or inoculants which were M7C3 carbides ＋ α-Fe did not change obviously. However, the prime M7C3 carbides morphology had great changes with the increase of RE nanoparticles, which changed from long lath to granular or island shape. When the content of RE nanoparticles was 0.4 wt.%, the microstructure of high chromium cast iron was refined greatly. The microstructure of carbides was coarser when the addition of RE nanoparticles was higher than 0.4 wt.%. The hardness and impact toughness of HCCIs were improved by addition of RE nanoparticles or inoculants. The impact toughness of HCCIs was increased 36.4% with RE nanoparticles of 0.4 wt.%, but the hardness changed slightly. In addition, the adding of RE nanoparticles or inoculants could reduce the degree of the brittle fracture. Fracture never seemed regular, instead, containing lots of laminates and dimples with the increase of the RE nanoparticles. The results also indicated that the optimal addition amount of the RE nanoparticles was 0.4%, under this composition, the microstructure and mechanical property achieved the best cooperation. In addition, through the study of erosion wear rate, when adding 0.4% RE nanoparticles into the HCCIs, the erosion wear rate got the minimum 0.32×10-3 g/mm2, which could increase 51.5% compared with that without any RE nanoparticles.

Biological soil crusts and their potential applications in the sand land over Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau is now experiencing ecological degradation risks as a result of climate change and human activities.The alpine grassland ecology in permafrost zones is fragile and susceptible to deterioration due to its high altitude,low temperature,and limited oxygen,which complicates the repair of damaged land.Biological soil crusts(BSCs)are crucial for land restoration in plateau regions because they can thrive in harsh conditions and have environmentally beneficial traits.Inoculated biological soil crust(IBSC)has shown success in low-altitude desert regions,but may not be easily duplicated to the plateau environment.Therefore,it is essential to do a comprehensive and multifaceted analysis of the basic theoretical comprehension and practical application of BSCs on the Tibetan Plateau.This review article aims to provide a brief summary of the ecological significance and the mechanisms related to the creation,growth,and progression of BSCs.It discusses the techniques used for cultivating BSCs in laboratories and using them in the field,focusing on the Qinghai-Tibet Plateau circumstance.We thoroughly discussed the potential and the required paths for further studies.This study may be used as a basis for selecting suitable microbial strains and accompanying supplemental actions for implementing IBSCs in the Qinghai-Tibet Plateau.

Microbial inoculants and garbage fermentation liquid reduced root-knot nematode disease and As uptake in Panax quinquefolium cultivation by modulating rhizosphere microbiota community

Objective:To find a suitable ecological cultivation measure to solve the problem of root-knot nematode disease of Panax quinquefolium(Panacis Quinquefolii Radix)and the heavy metals accumulating in its roots.Methods:Three-year-old P.quinquefolium was treated with four different combinations of microbial inoculant(MI)and garbage fermentation liquid(GFL)[the joint application of‘TuXiu’MI and Fifty potassium MI(TF),the combination use of‘No.1'MI and Fifty potassium MI(NF),‘Gulefeng’poly-γ-glutamic acid MI(PGA),GFL],and the untreated control(CK).Here,high-throughput sequencing,ICP-MS and UPLC were employed to systematically characterize changes of microbial diversity and structure composition,heavy metals(As,Cd and Pb)content and ginsenoside content among different treatments.Results:The results revealed that different MIs and GFL could increase the root dry weight of P.quinquefolium,PGA enhanced it by 83.24%,followed by GFL(49.93%),meanwhile,PGA and GFL were able to lessen root-knot nematode disease incidence by 57.25%and 64.35%.The treatment of PGA and GFL can also effectively reduce heavy metals in roots.The As content in GFL and PGA was decreased by 52.17%and 43.48%respectively,while the Cd and Pb contents of GFL and PGA was decreased somewhat.Additionally,the content of total ginsenosides was increased by 42.14%and 42.07%,in response to TF and NF,respectively.Our metagenomic analysis showed that the relative abundance of particular soil microbial community members related to the biocontrol of root-knot nematode disease and plant pathogen(i.e.,Chaetomium in NF,Xylari in GFL,and Microascus in PGA),heavy metal bioremediation(Hyphomacrobium in PGA and Xylaria in GFL),and nitrogen fixation(Nordella and Nitrospira in TF)was significantly increased;notably,potential harmful microflora,such as Plectosaphaerella and Rhizobacter,were more abundant in the control group.Conclusion:MI and GFL could improve the quality of P.quinquefolium by modifying its rhizosphere microbial community structure and composition,both of them are beneficial to the development of ecological cultivation of P.quinquefolium.

Agronomic evaluation of Herbaspirillum seropedicae strain ZAE94 as an inoculant to improve maize yield in Brazil

Diazotrophic bacteria applied as a seed inoculant can improve the grain yield of several crops including maize. The current study aimed to test the agronomic efficiency and contribution of biological nitrogen fixation(BNF) of the endophytic diazotroph Herbaspirillum seropedicae strain ZAE94 to maize under field conditions. Eighteen field assays were conducted in four different locations during consecutive years on two hybrids and two varieties of maize in a random block design with four replicates using a peat-based inoculant. The inoculant containing the ZAE94 strain was applied without nitrogen(N)fertilization or with 40 kg N ha^(-1) and was compared to the application of 40 and 80 kg N ha^(-1) without inoculation. Crop productivity and N accumulation in the grain were evaluated in addition to ^(15)N natural abundance(δ^(15)N) to evaluate BNF in the treatments without N fertilization. Fertilization at 40 kg N ha^(-1) plus bacterial inoculation produced crop yields similar to the treatment with 80 kg N ha^(-1) and increased grain N content, especially in the off-season with 40 kg N ha^(-1). The inoculation treatments showed lower δ^(15)N values than the non-inoculated treatments, which was most evident in the off-season. The BNF contributed about 30% of N accumulated in plants inoculated with ZAE94. On average, 64% of the N fertilized plots showed an increase of the parameters evaluated in the inoculated treatments, compared with the control. Inoculation also increased root length, root volume, and leaf area, and these parameters were positively correlated with plant weight using a hydroponic assay. This study revealed that the application of H. seropedicae inoculant increased the amount of N in plants owing to BNF, and there is a better chance of yield response to inoculation under low N fertilizer application in the off-season.

Biotransformation of Shrimp Wastes by Bacillus subtilis OKF04 and Evaluation of Growth Promoting Effect in Crop Planting

In this study,we proposed a reliable and sustainable technique for the clean utilization of shrimp wastes,which can yield a solid inoculant of Bacillus subtilis OKF04 containing micronutrients at low cost without the risk of contamination.Study of the culture conditions revealed that the head of shrimp Litopenaus vannamei and the wheat bran acted as suitable substrates for the growth of B.subtilis OKF04.With 60%initial moisture content,30℃culture temperature,and 5%inoculation amount,followed by 48 hours of fermentation and 0.5%soluble starch added during the drying process(50℃for 6h),a solid B.subtilis OKF04 inoculant with a spore amount of 2.4×10^(10)CFU g^(-1)and a high amino acid content was obtained.The solid B.subtilis OKF04 inoculant was applied to cultivate pakchoi under pot experiment.As the result,of adding to,the size of stems and leaves,nutritional composition,and physiological activity of pakchoi were significantly(P<0.05)enhanced by solid B.subtilis OKF04 inoculant.B.subtilis OKF04 also significantly(P<0.05)increased the soil’s nutrient content and improved its microbial composition.Furthermore,pakchoi cultivated with a low dose of solid B.subtilis OKF04 inoculant(0.05 g kg^(-1)soil)resulted in the best results.This study provides a new method for the preparation of microbial inoculants with solid waste shrimp heads.