Investigating the effect of silkworm excreta compost on the growth indicators of potted plant Syngonium podophyllum

Dissertation for obtaining a master's degree (M.Sc.)

Abstract

This experiment is to investigate the possibility of using silkworm waste compost as an organic fertilizer in order to reduce or at least adjust the amount of chemical fertilizers and also determine the best compost mixture for ornamental plants. Syngonium podophyllum was implemented. The treatments were: silkworm waste compost, tea waste, cocopeat, rice husk and perlite, which were mixed in different volume ratios. Syngonium rooted cuttings were grown in the form of randomized complete block design in 24 treatments and 3 replications in the greenhouses of Lahijan Flower and Ornamental Plant Research Station. The physical properties of the substrates such as apparent specific gravity, true specific gravity, percentage of porosity, volume percentage of water, volume percentage of air, water holding capacity, percentage of solid particles and percentage of ash as well as chemical properties such as EC, pH, percentage of total nitrogen, percentage of organic carbon, C/N ratio and the amount of phosphorus, potassium, calcium, magnesium, sodium, manganese and zinc elements were measured in the water extract taken from the substrate. Growth indices such as leaf number, leaf length and width, chlorophyll index, leaf surface, fresh and dry weight of shoot, number of lateral branches and plant height were measured. The highest growth was observed in the bed of tea waste 50% + perlite 50% + complete fertilizer, tea waste 50% + rice husk 50% + complete fertilizer and tea waste 45% + perlite 45% + silkworm waste compost 10%. Regardless of the complete fertilizer treatments, the beds whose raw materials were tea waste and silkworm waste compost showed a better growth rate than other culture beds. Also, the percentage of total nitrogen, C/N ratio and apparent specific gravity had a positive effect on plant growth. The use of silkworm waste compost increased the pH of the culture medium, while the use of tea waste in the mixture of the culture medium decreased the pH value of the culture medium.

Key words: houseplant, cultivation medium, silkworm waste compost, tea waste, rice husk, syngonium podophyllum

Predictions indicate that the Korean population will soon Earth will reach about 9 billion people (Kochaki et al., 2016). Achieving this means that another billion hectares of natural habitats, mainly in developing countries, will be converted to agricultural land, the consumption of chemical fertilizers, especially nitrogen, will increase to two or three times the current level, the demand for water will intensify, and the use of chemical pesticides will triple (Holl et al., 2005). The use of chemicals in agriculture has intensified since the Green Revolution in the 1960s with the production of more food. Chemicals destroy the useful living organisms of the soil and destroy the natural fertility of the soil. It also destroys the ability of biological resistance in the crops, thus making them susceptible to the attack of pests and diseases. Crops grown with chemicals are harmful to human health (Sinha et al. [1], 2001). Since the beginning of the 20th century, with the formation of the system of agriculture, which today is called common agriculture [2], various concerns were expressed about the consequences of this method. This concern increased in the middle of the last century with the excessive use of off-farm inputs, especially fertilizers and synthetic chemical pesticides, and the efforts to find alternative methods intensified, which finally led to the emergence of the concept of sustainable agriculture. By increasing the organic matter of the soil, these biofertilizers improve the physical, chemical and biological properties of the soil, and also provide the nutrients needed by plants and microorganisms. Identifying effective solutions to reduce the use of chemical fertilizers in order to control environmental pollution, using more bio-fertilizers and using plant and animal residues in order to provide a part of plant nutrition needs and improving the physical, chemical and biological characteristics of cultivated soils and appropriate planting and cultivation systems are important and effective measures in line with agricultural production (Malkoti, 1379). The methods cause minimal damage to the environment and increase the sustainability of agricultural systems.Organic agriculture means that chemical inputs are not used in the production of agricultural products during the production process. In this method, organic and animal fertilizers are used for soil fertility and biological methods are used to control pests and diseases (Pioest et al., 1387; Kochaki et al., 1376). On the one hand, the disposal of these wastes is an economic burden on the producers, and on the other hand, if these wastes are not disposed of properly, they can cause serious environmental risks. Because the place of disposal of these wastes can become a place for the accumulation of harmful insects and pathogens and endanger the health of the environment and human societies, and also lead to the pollution of water and soil resources (Orstarazo et al., 2001). Composting is a sustainable solution to deal with these wastes, because on the one hand it eliminates the problem of waste disposal and on the other hand it leads to the production of valuable products for use in agriculture. Every year, thousands of tons of tree bark waste are produced in the Iranian wood and paper factory (Chuka) and tea waste in tea processing factories, as well as the resulting waste from silkworm cultivation and rice waste in the northern region of the country, which as organic waste can be used as raw materials for composting. Pargat Dehkaei (1383) showed that the compost obtained from tree bark waste and tea as a substitute for peat moss has the ability to be used in the parsley cultivation bed. One of the main problems of the producers of ornamental plants, especially potted plants in our country, is the limited suitable cultivation beds. These substrates are different for different plants. The culture medium is one of the most important factors that affect the appearance of the plant (Lemir, 1995). Choosing a material as a suitable culture medium depends on the availability of that material, the price and the location of the experiment (Kolgart, 1983). Today, many ornamental leafy houseplants are grown in soilless cultivation beds in which peat is used as the base bed (Pool et al. [3], 1981). The purpose of this research is to investigate the potential of using silkworm waste compost as an organic fertilizer in order to reduce or at least adjust the amount of chemical fertilizers and its effect on the physical and chemical properties of the culture media, as well as to determine the best compost mixture as a culture media for the tested Syngonium plant.

Abstract

An experiment to determine the optimal substrate waste compost tea, Silkworm feces compost, coco peat, perlite and rice husk for Syngonium podophylium L. was done. Treatments consisted of silkworm waste composting, tea waste, cocopeat, perlite, waste rice husk, which were mixed in different proportions. Syngonium rooted cuttings in a randomized complete block design with 24 treatments and 3 replications in Research Station in greenhouse flower and ornamental plants were planted. Physical properties of substrates such as bulk density, true density, porosity, volume percent water, percent volume of air, water holding capacity, percent solids and ash and chemical properties such as EC, pH, total nitrogen percentage, percentage organic carbon, C / N ratio and the amount of phosphorus, potassium, calcium, magnesium, sodium, manganese, and zinc were extracted from the medium was measured. Growth parameters such as leaf number, leaf length, chlorophyll content, leaf area, shoot dry weight, number of lateral branches and plant height were measured.   Most of the plants growth mediums were observed in tea waste 50% + perlite 50% + fertilizer, tea waste 50% + rise husk 50% + fertilizer and tea waste 45% + perlite 45% + 10% silkworm faces. Regardless of the fertilizer treatment, the growth medium used by compost tea and silkworm faces had shown better growth rates than other substrates. The percentage of total nitrogen, C/N ratio and bulk density had a positive effect on plant growth.