复合微生物拮抗菌剂的研制及其在大棚甜瓜生产中的应用

从甜瓜大棚土壤中筛选出菌株FP2,它可有效抑制甜瓜白粉病病原菌、甜瓜枯萎病病原菌、甜瓜疫病病原菌和甜瓜霜霉病病原菌的生长,通过形态学、生理生化和分子生物学研究,FP2被鉴定为枯草芽孢杆菌。为增强该菌株的拮抗能力,用He-Ne激光诱变FP2,得到拮抗活性强且传代最稳定的突变株FP27和FP29,经发酵后将其按1∶1的比例制备成复合接抗菌剂。将复合拮抗菌剂和实验室前期生产的生化黄腐酸菌肥进行复配,首次研发出大棚甜瓜专用的生化黄腐酸复合微生物菌肥。将该菌肥应用于大棚甜瓜的生物防治,结果表明,该菌肥可有效防治大棚甜瓜各类病害的发生,甜瓜长势良好,含糖量高,具有显著的社会效益和经济效益。     

Constraints using the liquid fraction from roadside grass as a bio-based fertilizer

Background

Roadside grass cuttings are currently considered a waste product due to their association with road sweepings as contaminated waste, therefore, their potential as a biofertilizer is understudied.

Aim

This study aimed to determine whether grass liquid fraction (GLF) collected from a roadside verge in Maldegem, Belgium, and pressed using a screw press was suitable as a biofertilizer.

Methods

The characterization of the heavy metal content of the GLF was conducted using an ICP-OES. From May to September 2019, a pot experiment was set up using a randomized block design to compare tomato plant growth, yield, and nutrition for GLF-treated plants to two commercial fertilizers and tap water as a control.

Results

The heavy metal content of the GLF was below the maximum permissible concentrations (MPCs) for organic fertilizers as set out by the European Comission fertilizer regulation 1069/2009 and 1107/2009 (European Comission, 2019). However, despite having a fairly well-balanced nutrient content (0.1% N, 0.04% P₂O₅, and 0.2% K₂O), GLF had a negative effect on the growth, root weight, and yield of the tomato plants, killing six out of ten plants. GLF also promoted mold growth in the soil of some plants. Since the GLF was uncontaminated, heavy metal toxicity did not cause the negative effect.

Conclusions

Previous research showed that liquid fractions from some plants negatively affect the growth of others due to allelopathic chemicals; this, together with the stimulation of fungal growth, could have caused the negative effects observed. Future experiments will investigate the herbicidal property of GLF and possible treatments to potentially recover the nutrients contained within the GLF for application as a biofertilizer.     

Microalgal bioinoculants for sustainable agriculture and their interactions with soil biotic and abiotic components: A review

Modern agricultural practices have posed a detrimental impact on the environment due to their intensive use to meet the food demands of an ever-increasing population. In this context, microalgal bioinoculants, specifically cyanobacteria and green microalgae, have emerged as sustainable options for agricultural practices to improve soil organic carbon, nutrient availability, microbial quality, and plant productivity. An overview of current and future perspectives on the use of microalgal bioinoculants in agriculture practices is presented in this review, along with a discussion of their interactions with soil biotic and abiotic factors that affect soil fertility, plant health, and crop productivity. The benefits of microalgal bioinoculants include releasing agronomically important metabolites (exopolymers and phytohormones) as well as solubilizing soil nutrients. Furthermore, they function as biocontrol agents against soil-borne pathogens and facilitate the establishment of rhizosphere communities of agricultural importance. So far, very few studies have explored the basic mechanisms by which microalgal bioinoculants interact with soil biotic and abiotic factors. In recent years, advanced molecular techniques have contributed to a better understanding of these interactions.     

Isolation of a Phytase-Producing Bacterial Strain from Agricultural Soil and its Characterization and Application as an Effective Eco-Friendly Phosphate Solubilizing Bioinoculant

In the present study, we isolated from agricultural soils, a Bacillus strain designated SD01N-014, expressing high-level extracellular phytase activity and investigated its potential to be used as a soil phosphate-solubilizing bioinoculant to improve soil phosphorus (P) availability and thus enhance plant growth. Soil inoculation test showed that being as an inoculant, SD01N-014 substantially enhanced soil P nutrition. Pot experiments showed that when applied to soils, SD01N-014 is capable of colonizing maize seedling roots, increasing plant-available P levels in the rhizosphere and promoting seedling growth. High tunnel trials with different vegetable plants demonstrated that SD01N-014 as a soil inoculant greatly promoted plant growth and was positively correlated with inoculum sizes. Together, these results indicate that SD01N-014 holds promising potential as a cheap, viable and eco-friendly alternative to chemical P fertilizers for increasing soil fertility and crop production in sustainable farming.     

生物肥料培肥水稻秧床对土壤酶活性的影响

以应用生物肥料培肥水稻育秧苗床,研究培肥方式对不同土壤酶活性的影响。结果表明：普通水稻土进行培肥处理后作为水稻育秧苗床,秧苗期土壤脱氢酶、脲酶、纤维素酶、蛋白酶的活性增强,硝态氮含量明显提高,其中采用生物肥料快速培肥比常规营养土效应明显。而盐碱土采用生物肥料快速培肥处理的土壤脱氢酶、脲酶、蛋白酶活性及硝态氮含量与未培肥的普通水稻土差异不大。说明采用生物肥料快速培肥有利于提高土壤酶活性、促进养分转化、提高土壤供肥力,但其培肥效果受盐分的影响。     

球毛壳菌生物菌肥对草莓生长和品质的影响

【目的】研究球毛壳菌生物菌肥不同用量对草莓植株生长、果实产量和品质的影响,为球毛壳菌生物菌肥在生产上的应用提供参考。【方法】在温室大棚中开展试验,按不同球毛壳菌生物菌肥施肥量（0.5、1.0、2.0g/株）设3个处理,不施肥为对照处理,检测内生真菌球毛壳菌ND35在草莓上的定殖率;分析不同菌肥用量对草莓生物量和生理指标及果实产量和品质的影响。【结果】球毛壳菌ND35可以在草莓植株内定殖,其定殖率与菌肥用量正相关。不同处理的球毛壳菌生物菌肥对草莓植株生长、果实产量和品质具有显著影响,施用0.5g/株和1.0g/株的菌肥用量有利于草莓的生长和发育。【结论】0.5~1.0g/株用量的球毛壳菌生物菌肥可提高草莓产量和改善其品质,球毛壳菌生物菌肥可应用于草莓田间大规模生产中。     

Evaluation of cultivation methods and sustainable agricultural practices for improving shallot bulb production – a review

Abstract

Shallot is an economically important nutritive bulb vegetable and medicinal plant from Alliaceae family. Distributed in limited regions worldwide, in most cases, shallots widely grow in very cold to moderate cold temperate climates at high elevations required to induce bolting and overcome their bulbs and true seeds dormant period. Shallot responses to agricultural management and environmental conditions vary among different species and genotypes and, thus, selection of the elite genotypes is a prerequisite for obtaining desired yield and quality of bulbs and true seeds. Plant material (seed or bulb), plant selection, as well as cultivation and agricultural practices (importantly fertilization, spacing, planting date, and irrigation in greenhouse or farmland) critically affect productivity, phytonutrient value, and economic profit of the shallot produces. The knowledge of using biofertilizers and mulching techniques on shallots are currently evolving, but the information on the efficiency of nanobiofertilizers and eco-friendly and biodegradable mulching materials on shallots farming are still lacking. With the emphasis on sustainable agricultural systems, the efficiency of combined organic and inorganic fertilization is discussed and the potential biofertilizer agents are recommended. This review highlights the importance of using the integrated fertilization (organic and inorganic methods combined with biofertilizers) and irrigation methods (such as two-line spray hose irrigation combined with mulching), and the practices with the highest potential to further improve shallot farming are suggested. The information on shallots breeding is still lacking and requires extensive researches in the future.     

Silicon and plant nutrition—dynamics,mechanisms of transport and role of silicon solubilizer microbiomes in sustainable agriculture: A review

Silicon (Si) is the second most abundant element in the Earth’s crust and has numerous roles in both soils and plants, although it is inaccessible to plants in its native state (insoluble silicate minerals). This inaccessibility can lead to insufficiency, which induces anomalies in plant growth and development.Specifically, Si alleviates various biotic and abiotic stresses in plants by enhancing tolerance mechanisms at different stages of uptake/deposition as a monosilicic acid. Exclusive utiliz...     

Influence of indigenous inputs on the properties of old alluvial soil in a mustard cropping system

Field experiments were conducted at the Crop Research and Seed Multiplication Farm of Burdwan University, Burdwan, West Bengal, India, to evaluate the influence of integrated nutrient management on soil physicochemical properties in a mustard (Brassica campestris cv. ‘B9’) cropping system. The experiment was conducted during the winter seasons of 2011–2012 and 2012–2013 in old alluvial soil (pH 6–7). Seven different doses of biofertilizers (Azotobacter and phosphate solubilizing bacteria (PSB)), vermicomposts, organic (cow dung), and chemical fertilizers were applied on mustard in both the experimental seasons. The results indicated an improvement in soil quality by increasing soil porosity and water holding capacity significantly, as well as gradual build-up of the soil micronutrient status after harvesting of the crop. Dual applications of biofertilizers and vermicomposts have contributed significantly to higher soil organic matter, available nitrogen (N), phosphorus (P), and potassium (K) contents as well as micronutrient availability of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) and subsequently increased the soil health.     

Evaluating the effectiveness of biofertilizer on salt tolerance of cotton (Gossypium hirsutum L.)

In the present study, the effectiveness of biofertilizer containing plant growth promoting rhizobacteria was evaluated on growth and physiology of cotton under saline conditions. Cotton plants were exposed to different levels of NPK (50%, 75%, and 100% of recommended levels) along with coating with biofertilizer under saline (15 dS m^?1) and non-saline conditions. It was observed that the biofertilizer seed coating improved growth, physiological (relative water content and chlorophyll content index), and ionic (K⁺/Na⁺) characteristics under saline and non-saline conditions. However, shoot growth (shoot fresh and dry weight) and leaf gas exchange characteristics (CO₂ assimilation rate, A; intercellular CO₂ concentration, C_i; transpiration rate, E; stomatal conductance, g_s) were decreased by biofertilizer coating under saline condition. Increasing levels of NPK fertilizer increased shoot growth, whereas root growth was maximum at 75% NPK level under saline conditions. The results of the study indicate that the biofertilizer application was very effective for cotton plant in non-saline conditions but not very effective in saline conditions.