Sustainable living and healthy lifestyles have increased the interest in home gardening. Organic fertilisers are best for growing vegetables or agricultural produce for healthier and chemical-free options.
Kitchen scrap and garden waste can be reused to create nutrient-rich organic fertilisers. Fruit and veggie peels, coffee grounds, tea leaves, and eggshells are kitchen scraps that can be used, whereas grass clippings, leaves, and plant trimmings are common garden wastes. The following are some DIY techniques to convert these into organic fertilisers.
Composting decomposes organic materials into nutrient-rich end-products. This is a simple way to recycle kitchen scraps and garden waste as fertiliser or planting media.
To begin, collect kitchen scraps and garden waste, chop them, and layer them in a compost bin or pile.
Mix nitrogen-rich green materials (fruit or vegetable scraps, coffee grounds, and fresh grass clippings) and carbon-rich brown materials (dry leaves, sawdust, and straw). Adding soil, brown sugars, and molasses will speed up this process.
Water until the compost is moist (not too wet nor dry), and aerate the compost by turning it regularly to facilitate decomposition. Eventually, the compost will turn dark and crumbly and can be used as a fertiliser.
Vermicomposting uses worms to break down organic matter even faster. Vermicomposting can be initiated by digging a hole in the backyard to attract local earthworms to decompose the waste.
Vermicomposting can also be performed indoors in a worm bin or in a shaded area of the garden.
Normally, bedding materials such as shredded newspapers or cardboard are added to the bin before earthworms are introduced or lured.
Then, gradually add kitchen scraps and garden wastes, burying them in the bedding material. Worms will consume the organic matter and produce nutrient-rich castings, which can be used as fertilisers.
Liquid organic fertilisers, whether tea (extracts) or fermented, are beneficial for nutrient-hungry seedlings and young plants. Start by gathering kitchen and garden wastes in a container and adding water. Allow this mixture to steep for several weeks, stirring occasionally. This process leaches nutrients from organic materials and produces a rich liquid. For further dilution, add more water before feeding the plants.
Additionally, enclosing compost in cloth and immersing it in water can yield compost tea.
Other forms of liquid fertilisers include fermented plant juice (FPJ), fermented fruit juice (FFJ), and fermented amino acids (FAA).
To prepare FPJ, gather fresh plant (typically vegetable leaves) waste and brown sugar in equal quantities. In a suitable container, layer them alternately until it is three-quarter full.
Close the container with a kitchen towel or lid and ferment it for a week. Use a ratio of one part waste to one part brown sugar or molasses for this recipe.
The same ratio also applies to fruit peel and fish waste to create FFJ and FAA, respectively. After fermenting for one to two weeks, transfer the fermented extracts to freshly labelled bottles for storage. Store these extracts in cool, shaded areas.
Before using, dilute them with tap water at a ratio of 1:800 to 1:1000. These materials are rich in nutrients and contain beneficial microorganisms and plant-inducing hormones that will promote healthy plant growth and add organic matter to the soil.
Another beneficial liquid fertiliser is fermented or fresh washed rice water. Adding rice water has been shown to nourish plants.
However, it is essential to note that certain materials, such as meat, dairy products, and oily foods, should be avoided because they can attract pests and cause unpleasant odours.
It is also important to note that not all kitchen scraps can be used for composting or vermicomposting, because some materials take longer to decompose.
However, with practice and experimentation, you will find a balance that works best for your needs.
Beginners can easily make organic fertilisers from kitchen and garden wastes. The reuse of materials that would otherwise be discarded creates nutrient-rich compost or liquid fertilisers, improving the health and productivity of the garden.
So, get your compost or worm bin ready and start sustainable gardening with homemade organic fertilisers for the benefit of your plants and environment.
Dr Noraini Md Jaafar is a soil microbiologist at the Department of Land Management, Faculty of Agriculture, Universiti Putra Malaysia. She is an advocate of organic farming, and she teaches communities sustainable farming techniques and waste recycling.