Liquid organic fertilizer formulated from silkworm waste: mulberry leaves, silkworm excrement, cocoons and combinations thereof.

Abstract

A liquid organic fertilizer consisting of: a mixture of silkworm excrement sludge, mulberry leaf waste sludge and cocoon sludge, the formulation providing macro- and micronutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, zinc, manganese, copper and boron in bioavailable forms.

Description

Technical field of the invention:

[0001] The present invention relates to the field of sustainable agriculture and the development of organic fertilizers. In particular, it relates to a novel formulation of a liquid organic fertilizer produced from by-products of silkworm breeding, including mulberry leaf waste, silkworm excrement, and cocoon shells. The invention provides a nutrient-rich, microbially active fertilizer capable of improving soil fertility, increasing nutrient retention, and promoting plant growth, while simultaneously addressing the waste management challenges of the silkworm breeding industry. Background of the invention:

[0002] Agriculture has traditionally relied on synthetic chemical fertilizers to meet the growing demand for food production. While these fertilizers contribute significantly to short-term crop yields, their long-term impact on soil quality, environmental sustainability, and ecological balance has raised global concerns. Overuse of chemical fertilizers leads to soil acidification, degradation of organic matter, reduced microbial activity, and groundwater contamination. Furthermore, the rising costs of chemical fertilizers and their reliance on fossil fuels are making them economically unsustainable for small-scale and subsistence farmers.

[0003] Parallel to this problem, silkworm farming—an agrarian industry focused on silk production—generates enormous quantities of organic byproducts such as mulberry leaf waste, silkworm excrement, and unwindable cocoons. While mulberry leaves are the primary food source for silkworms, significant amounts of partially consumed and decomposed leaves remain unused after the rearing cycles. Similarly, silkworm farming produces large quantities of excrement, and unwindable or defective cocoons are often discarded as waste. These wastes, although nutrient-rich, are largely unused and often pose challenges for environmentally sound disposal.

[0004] Scientific studies have shown that silkworm byproducts are naturally enriched with nitrogen, potassium, phosphorus, calcium, magnesium, and other micronutrients essential for plant growth. Furthermore, they contain organic carbon and harbor diverse microbial populations, including nitrogen-fixing and phosphorus-releasing organisms. Despite this, no commercial approach has yet been developed to convert these byproducts into a stable and potent fertilizer composition.

[0005] The need for environmentally friendly and resource-conserving agriculture has led to innovations in organic fertilizers. Composting, vermicomposting, and bio-fertilizers are examples of sustainable alternatives, but they often have limitations such as long processing times, inconsistent nutrient composition, and a lack of microbial diversity. Furthermore, liquid bio-fertilizers currently available on the market are often derived from single microbial inoculants or plant extracts, thus lacking the diversity of sources required to restore balanced soil fertility.

[0006] In this context, the present invention introduces a liquid organic fertilizer produced by combining mulberry leaf sludge, silkworm excrement sludge, and cocoon sludge, resulting in a formulation with improved availability of macro- and micronutrients, stable pH, high microbial activity, and long shelf life. The invention not only reduces agriculture's dependence on chemical fertilizers but also addresses the challenges of waste management in the silkworm breeding industry. By integrating nutrient recycling with sustainable crop management, this invention embodies the principles of the circular economy and climate-smart agriculture. Summary of the invention;

[0007] The invention provides a novel liquid organic fertilizer formulation derived from silkworm breeding waste. The process comprises the preparation of individual sludges from silkworm excrement, mulberry leaf residues, and unwindable cocoons, followed by their controlled mixing to obtain a stable liquid formulation enriched with both nutrients and beneficial microorganisms.

[0008] The resulting fertilizer has a balanced pH (6.7-7.0), an electrical conductivity in the optimal range for nutrient uptake, and exceptionally high potassium levels (up to 1407 ppm), along with significant amounts of nitrogen, phosphorus, calcium, magnesium, and sulfur. The formulation is also enriched with micronutrients such as iron, zinc, copper, manganese, and boron, which are crucial for plant enzymatic functions and growth regulation.

[0009] A key feature of the invention is the sustained microbial load, with total bacterial counts exceeding 10 8 cfu / g, as well as the presence of nitrogen-fixing bacteria, phosphate-releasing bacteria, actinobacteria, and fungi. These microorganisms improve nutrient availability, maintain soil biodiversity, and support long-term soil fertility.

[0010] Post-treatment studies confirm that the fertilizer significantly improves soil organic carbon content, micronutrient retention, and microbial population. Compared to untreated soils, the treated soils exhibit increased nitrogen and phosphorus content, a higher microbial count, and improved nutrient retention capacity. This demonstrates that the invention not only provides an immediate nutrient supply for plants but also promotes long-term soil health.

[0011] The liquid formulation is shelf-stable, cost-effective, and compatible with various application methods, including foliar fertilization, fertigation, and seed treatment. Its environmentally friendly nature eliminates the risks of chemical residues in soil and groundwater. Furthermore, by transforming silkworm waste into a value-added product, the invention offers economic advantages to silk farmers and contributes to sustainable resource management.

[0012] In summary, the invention represents a groundbreaking advance in organic fertilizer technology by combining waste recycling, soil quality improvement, and sustainable increases in crop productivity. Detailed description of the invention:

[0013] The present invention introduces a novel liquid organic fertilizer formulated from by-products of silkworm breeding, including mulberry leaves, silkworm excrement, and non-rollable cocoons. The detailed description explains the manufacturing process, compositional properties, microbial enrichment, application methods, and performance evaluation of the fertilizer for improving soil quality and plant nutrition. The invention not only demonstrates scientific innovations in nutrient recycling and microbial integration but also represents an ecological approach to waste management in the silkworm breeding industry.

[0014] The process begins with the systematic collection of raw sericulture waste from the farms, including mulberry leaf residue discarded during silkworm feeding, excrement excreted by the silkworms during rearing, and defective cocoons unsuitable for reeling. These materials are naturally rich in organic matter, minerals, and bioactive compounds. However, in their raw state, they are not directly suitable for agricultural use due to uneven nutrient distribution, high moisture content, and potential odors from decomposition. Therefore, the invention emphasizes controlled sludge preparation as a first step in stabilizing and standardizing the waste into a usable fertilizer.

[0015] To achieve this, mulberry leaves, silkworm excrement, and cocoon waste are individually processed into aqueous stillages under controlled conditions. The mulberry leaf stillage maintains a slightly acidic to neutral pH and contains significant amounts of potassium, calcium, magnesium, and sulfur, as well as trace amounts of micronutrients such as iron, manganese, zinc, and boron. The silkworm excrement has a nutrient-rich profile with high potassium and nitrogen content, while the cocoon sludge offers a unique combination of proteins, calcium, and micronutrients derived from silk residues. Each sludge contributes beneficially on its own, but when combined in optimized ratios, they result in a balanced nutrient spectrum that supports both immediate plant uptake and long-term soil fertility.

[0016] Once the lees are prepared, they are mixed in predetermined ratios to create the final fertilizer composition. The mixing process is not arbitrary; it is guided by chemical and microbiological analyses to ensure nutrient stability, compatibility of the microbial communities, and a consistent pH suitable for agricultural application. The final mixture has a pH between 6.7 and 7.0, which is considered ideal for nutrient solubility and uptake by plants. Electrical conductivity measurements show that the formulation provides a sufficient ionic concentration to deliver nutrients without causing soil salt stress. The final product retains a high moisture content, which facilitates its application as a liquid fertilizer.

[0017] One of the remarkable aspects of this invention lies in the microbial profile of the final formulation. Unlike chemical fertilizers, which only supply inorganic nutrients, this organic formulation incorporates actively living microbial populations that play a crucial role in nutrient cycling. Microbiological analyses show that the total viable count remains constant at 10 8 The CFU / g value exceeds [value missing], indicating a rich presence of beneficial microorganisms. The formulation contains nitrogen-fixing bacteria that convert atmospheric nitrogen into biologically available forms for plants, phosphate-dissolving bacteria that make insoluble phosphate compounds accessible to plant roots, and actinobacteria that contribute to the decomposition of organic matter and disease suppression. Furthermore, fungal populations promote nutrient degradation and contribute to symbiotic interactions between soil and plants.

[0018] The presence of these microorganisms provides a dual benefit: they not only directly replenish the soil's nutrient content but also foster an environment that promotes the preservation of native soil microbiota. This leads to improved soil biodiversity, better nutrient retention, and a long-term improvement in soil quality. The invention ensures that the microbial populations remain viable over extended storage periods, making the fertilizer stable and suitable for commercial distribution. Stability is achieved by maintaining an appropriate pH, nutrient balance, and moisture content that support the microbes' survival without triggering premature decomposition.

[0019] Chemical analysis of the compound fertilizer formulation shows that the potassium concentration reaches up to 1407 ppm, which is significantly beneficial for strengthening plant vigor, improving water regulation, and promoting flowering and fruiting. The nitrogen concentration ranges between 180 and 220 ppm, ensuring a steady supply for vegetative growth and protein synthesis in plants. The phosphorus content is between 60 and 72 ppm, which is essential for root development and energy transfer within plant cells. Furthermore, calcium, magnesium, and sulfur are present in concentrations that promote cell wall stability, chlorophyll synthesis, and enzymatic activity, respectively. Micronutrient analysis confirms the presence of iron, zinc, copper, manganese, and boron in bioavailable forms.These micronutrients play a crucial role in the physiological processes of plants, such as enzyme activation, reproductive development, and disease resistance.

[0020] The production of the fertilizer involves several controlled steps that ensure reproducibility and effectiveness. First, each type of waste is washed to remove impurities and then homogenized with water to form a slurry. The sludge undergoes mild fermentation under aerobic conditions, which promotes microbial enrichment and the degradation of organic matter. This fermentation phase is crucial for activating nitrogen-fixing and phosphorus-releasing organisms naturally present in the waste. Once the individual sludge mixtures are stabilized, they are blended in defined ratios, thoroughly mixed, and stored under controlled temperature conditions to prevent nutrient loss. The resulting product is a homogeneous liquid fertilizer ready for agricultural use.

[0021] The invention offers significant advantages in terms of application flexibility. The fertilizer can be applied directly by immersion in the soil, allowing nutrients and microbes to efficiently penetrate the root zone. It can also be used in fertigation systems, where it is delivered through irrigation channels to ensure uniform distribution across large fields. Application as a foliar fertilizer is another possibility, where diluted fertilizer is sprayed directly onto the leaves of the plants, enabling rapid nutrient uptake. Furthermore, the fertilizer can be used in seed treatments, where the seeds are soaked in diluted formulations before sowing to improve germination and early plant vigor by providing nutrients and beneficial microbes from the outset.

[0022] Extensive soil application studies were conducted to assess the fertilizer's effects on soil nutrient retention and microbial dynamics. Five soil samples treated with the fertilizer were analyzed for organic carbon, nitrogen, calcium, iron, zinc, and microbial content. The results consistently showed increased organic carbon levels, ranging from 3% to 10% depending on the soil type. Nitrogen levels improved significantly, confirming the fertilizer's role in enhancing soil nitrogen reserves. Micronutrient retention was also markedly improved, with zinc and iron levels showing substantial increases. Microbiological analyses of the treated soils revealed significantly higher total viable counts compared to untreated soils, demonstrating that the fertilizer not only introduces microbes but also promotes their proliferation within the soil system.

[0023] The improved nutrient retention capacity observed after fertilizer application highlights its role in sustainable soil management. Traditional chemical fertilizers, due to their high solubility, often lead to nutrient leaching, resulting in groundwater pollution and nutrient waste. In contrast, this organic formulation binds nutrients within the soil matrix, supported by microbial activity and organic matter content, thereby reducing nutrient losses and ensuring longer-lasting availability for plant uptake. This characteristic directly translates to reduced input requirements for farmers, lowering costs while maintaining or even increasing yields.

[0024] Another remarkable feature of the invention is its environmental compatibility. By transforming silkworm waste into a value-adding fertilizer, the invention contributes to circular economy practices by closing the loop between waste generation and agricultural productivity. Upgrading mulberry leaves, silkworm excrement, and cocoons reduces the environmental impact of waste disposal, which could otherwise lead to odor, pest attraction, or landfill problems. Furthermore, replacing chemical fertilizers with this organic alternative reduces the carbon footprint associated with industrial fertilizer production and mitigates soil and water pollution caused by synthetic agrochemicals.

[0025] The invention also offers socio-economic benefits. Silkworm breeders and silk producers, who often struggle with the disposal of byproducts, can now use or sell these waste materials as raw materials for fertilizer production. This creates additional income streams and employment opportunities in rural areas, while simultaneously reducing dependence on imported chemical fertilizers. The low-cost, locally sourced nature of the raw materials ensures affordability for small-scale farmers, thus democratizing access to sustainable agricultural solutions.

[0026] The commercial scalability of the fertilizer production process was taken into account in the invention. Sludge preparation and mixing processes can be easily adapted to larger volumes by using standard agricultural processing equipment such as mixers, fermenters, and storage tanks. The fermentation process requires only basic monitoring of pH, temperature, and microbiological counts, which can be managed using conventional laboratory techniques. The final product can be packaged in liquid form in bottles, drums, or bags, facilitating transportation and application.

[0027] From a scientific perspective, the invention combines the benefits of nutrient recycling, microbial enrichment, and soil management in a single formulation. While mulberry leaves contribute significant amounts of potassium and calcium, silkworm excrement provides nitrogen and organic matter, and cocoons supply proteins and micronutrients. The synergy between these components results in a fertilizer superior to any single-ingredient organic fertilizer. Microbial enrichment further distinguishes the invention from traditional composts or vermicomposts, as the inclusion of functional microbial groups provides an active mechanism for nutrient mobilization and soil fertility improvement.

[0028] In comparative trials with chemical fertilizers, the liquid organic fertilizer demonstrated equivalent or superior performance in terms of plant growth, yield, and quality. Plants treated with the formulation showed improved root development, greener foliage, and increased flowering and fruiting compared to control groups. Long-term indicators of soil quality, such as organic carbon content and microbial biodiversity, showed consistent improvement with repeated applications of the organic fertilizer, whereas soils treated with chemical fertilizers often exhibited signs of degradation over time.

[0029] In summary, the detailed description highlights that the invention represents an innovative, practical, and environmentally responsible approach to the production and application of fertilizers. By integrating silkworm waste recycling with agricultural sustainability, the invention not only addresses pressing challenges such as soil degradation, nutrient depletion, and waste management, but also contributes to food security and the economic development of rural areas. The unique combination of the fertilizer recipe—high nutrient content, microbial diversity, soil enrichment potential, and environmental friendliness—underlines its novelty and inventiveness, establishing it as a breakthrough in the field of organic fertilizers.

Claims

[1] A liquid organic fertilizer consisting of: a mixture of silkworm excrement sludge, mulberry leaf waste sludge and cocoon sludge, the formulation providing macro- and micronutrients such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, zinc, manganese, copper and boron in bioavailable forms. [2] Fertilizer according to claim 1, wherein the formulation has a potassium concentration between 1180 ppm and 1410 ppm, a nitrogen concentration between 180 ppm and 220 ppm and a phosphorus concentration between 60 ppm and 72 ppm. [3] Fertilizer according to claim 1, wherein the microbial population 10 8 exceeds cfu / g and includes nitrogen-fixing bacteria, phosphate-dissolving bacteria, actinobacteria and fungi that are able to improve nutrient mobilization in the soil and biodiversity. [4] Fertilizer according to claim 1, wherein the formulation maintains a stable pH value between 6.7 and 7.0 and an electrical conductivity between 5.5 and 6.0 mmhos / cm to ensure optimal nutrient uptake by plants. [5] Fertilizer according to claim 1, wherein the application improves the storage of organic carbon in the soil, increases the availability of micronutrients and increases the density of the microbial population compared to untreated soil.