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Effect of plant growth-promoting bacteria and undersown crops on the total protein content of spring barley grain grown in organic agriculture
Combination of cover crops and bacterial consortia reduce weediness in organic spelt wheat in Central Europe
Cultivation technologies based on the use of microbiological preparations or the introduction of cover crops in organic farming are alternatives to chemical plant protection products. To confirm this hypothesis, field studies were conducted in central Poland in 2019–2022 to determine the effect of bacterial consortia and green fertilizers from cover crops on the dry mass, abundance and species composition of dominant weed species occurring in spelt wheat grown in organic farming. Two factors were researched: I. Bacterial consortia: control treatment (no bacteria), bacterial consortium I (Azotobacter chroococcum + Azospirillum lipoferum Br17), bacterial consortium II (Bacillus megaterium var. phosphaticum + Arthrobacter agilis), bacterial consortium III (Azotobacter chroococcum + Azospirillum lipoferum Br17 + Bacillus megaterium var. phosphaticum + Arthrobacter agilis), II. Cover crops: control treatment (no cover crops), red clover, red clover + Italian ryegrass, and Italian ryegrass. Spelt wheat was harvested in late July. Just before harvesting, weeds were sampled to determine their dry matter, number, and species composition. The research clearly demonstrated that the application of bacterial consortia with cover crops significantly reduced the dry matter and number of weeds, including the dominant species. The greatest reduction in weed number was recorded in treatments after the application of bacterial consortium III in combination with plowing cover crops of red clover and a mixture of red clover and Italian ryegrass.
Influence of plant growth-promoting bacteria and green manures on the degreeof weed infestation in Triticum spelta in organic farming
Consortia of Plant Growth-Promoting Rhizobacteria and Selected Catch Crops for Increasing Microbial Activity in Soil under Spring Barley Grown as an Organic Farming System
In order to protect and remediate soils, organic farming methods have grown in popularity. The aim of the study was to evaluate the effect of rhizobacteria (Bacillus subtilis, Bacillus amyloliquefaciens, Pseudomonas fluorescens) and catch crops (undersown red clover alone, undersown Italian ryegrass alone and a mixture of clover and ryegrass) on the microbiological activity of the soil under organic spring barley. In 2019–2021, a field experiment was carried out on an organic farm, randomly in eight variants, each in three repetitions. The following parameters were analyzed: enzymatic activity of dehydrogenases (DHA), acid phosphatase (PAC) and catalase (CAT), soil fertility index (BIF), and a number of selected physiological groups of microorganisms (molds, bacteria, and actinomycetes). Compared to the control variant (without catch crops and bacteria), the values of DHA, CAT, and BIF increased significantly in the variant in which rhizobacteria and catch crops were used simultaneously. The highest BIF, of 32, was obtained in 2019, after the application of red clover catch crop + Italian ryegrass + rhizobacteria. PAC activity dropped significantly after the application of the bacterial consortium alone and was lower than the control by an average of 30%.
The Use of a Composition of Bacterial Consortia and Living Mulch to Reduce Weeds in Organic Spring Barley Cultivation as an Element of Sustainable Plant Production
Weed infestation of cereal crops in organic farming is becoming a serious problem in agriculture. Sustainable agriculture requires the search for and implementation of crop management techniques that will reduce weeds without negatively impacting the environment. This research refers to the principles of integrated plant protection in sustainable agriculture, allowing the use of chemical plant protection products to be limited to the absolute minimum. Technology for growing spring barley based on the use of bacterial consortia in combination with living mulch (LM) can be an interesting approach to this problem. The aim of this three-year field research was to determine the effects of bacterial consortia and LM on the level of weed infestation in the organic spring barley crop. Two factors were tested in the experiment: bacterial consortia factors: control (without bacterial consortia); 1—Bacillus megaterium var. phosphaticum and Arthrobacter agilis; 2—Bacillus subtilis, Bacillus amyloliquefaciens, and Pseudomonas fluorescens; and LM: control (without LM); red clover; red clover + Italian ryegrass; and Italian ryegrass. This research demonstrated that the bacterial consortia tested significantly reduced both the biomass and number of weeds, including the following dominant weeds: Chenopodium album, Sinapis arvensis, Elymus repens, and Tripleurospermum inodorum. The use of LM also significantly reduced the weed infestation of spring barley stands. The lowest biomass and number of weeds, with the exception of Elymus repens, were recorded on objects with LM Italian ryegrass in spring barley in combination with bacterial consortium 2. The introduction of cultivation with LM Italian ryegrass or its mixture with red clover and the use of bacteria should be recommended for the practice of sustainable agriculture, which will reduce weeds through an ecological method.
A Case Study on the Effect of Foliar Nitrogen Fertilization on the Microbiological and Biochemical State of the Soil and the Uptake of Macro- and Microelements by Winter Triticale (Triticosecale)
Due to the increasing demand for food, the agricultural sector is facing a huge challenge related to its production without having a negative impact on the environment. The above issues are regulated by the current EU policy, indicating the need to conduct plant production by the European Green Deal strategy (2020), based on reducing the use of chemical plant-protection products by 50% and reducing the level of mineral fertilization by 20% by 2030. Using appropriate techniques of applying mineral fertilizers, which have a positive effect on the development and activity of soil microorganisms, the availability of nutrients in the soil can be increased while reducing fertilizer applications. This study aims to show whether the use of foliar nitrogen fertilizers in combination with sulfur in a two-year field experiment with triticale stimulates the multiplication of selected groups of microorganisms and the level of soil enzymatic activity. In addition, effects on the content of available forms of nutrients in the soil, triticale yield, and total nutrient uptake were analyzed. It is shown that the applied foliar fertilizers enriched with sulfur, compared to fertilization with ammonium nitrate, contributed to a 100% increase in the number of analyzed groups of microorganisms, urease, and alkaline phosphatase activity; a 44% increase in dehydrogenase activity; and a 15% increase in acid phosphatase activity. The hybrid application technique, with reduced doses of nitrogen fertilizers enriched with sulfur by 20 and 25%, resulted in grain yields exceeding 8 t/ha. Moreover, compared to conventional fertilization based on ammonium nitrate, an increase in the grain yield of triticale was obtained in the range of 16 to 24%, as well as an increase in the accumulation of nutrients in the plant. It is shown that foliar fertilization is a promising alternative to standard fertilization techniques.