Policies to use natural ecosystems to sequester and store carbon should be accompanied by technological solutions (
Abdul, 2013).
Miyawaki, (1992), a Japanese botanist developed a reforestation method called Miyawaki forest to create a dense forest with diverse and rapidly growing native trees. This technique involves planting a mix of native plant species nearby, mimicking the structure of natural forests. The closed spacing helps the plantation to mature faster and become more resilient. The data published by various authors on afforestation programs indicate that the process couldn’t prevent the rise in Global temperature, which implies that deforestation is faster than the afforestation process.
Restoration
Miyawaki plantation has been used to restore degraded soil and lands throughout the World, A similar attempt was made at SRM College of Agricultural Sciences (Fig 1) to ameliorate the bulky soil by Miyawaki plantation with native trees. Across the world, many ecologists and scientists have proposed, tried and implemented various concepts of restoration of natural agro-ecosystem achieving a balance between human needs and biodiversity. Miyawaki plantation can also be deûned as ‘an intentional activity that initiates or accelerates recovery of an ecosystem concerning its health, integrity and sustainability’
(Aronson et al., 2010). One reliable forest restoration method is “native forests by native trees” based on knowledge of the area’s potential vegetation and the methods of germination and growth (
Miyawaki, Frank and Golley 1993). This research confirmed that the poor soil can be regenerated with Modified Miyawaki plantation and sustained in two years (Fig 2).
Soil amelioration
The organic mixture (Fig 3) included in this study; paddy husk, coco-peat and Farm yard manure reduced the bulkiness and increased the secondary growth and biodiversity of the Miyawaki plantation.
Species selection
Akira Miyawaki’s method of Afforestation was introduced as an ecological method of Afforestation to focus on “native forests by native trees” (
Miyawaki, 2004) the most effective way to restore the natural environment locally and globally, fight climate change, buffer natural disasters and build a resilient and sustainable future. Choosing the right species combination is the most important component of the Miyawaki way of Afforestation. The selection was made based on an extensive survey of the ecology and natural environment of the local area for the restoration activity. The selected species (Table 1) generally have a straight and deep tap root and are planted with a large selection of companion species. (
Miyawaki, 1989). In the current study, three species
Syzygium cumini,
Madhuca longifolia and
Pongammia pinnata native to the geographical location of the study area were planted to evaluate carbon absorption. The mixing of species reflects their natural patterns of associations in the forests (
Padilla and Pugnaire 2006). Four plants per square metre, a square pattern produced a dense plantation in this research. Soil amelioration activity in ecosystem restoration and environmental conservation is needed, as healthy soils contribute to biodiversity and water quality. This study agrees that the survival percentage of three native plant species
Syzygium cumini,
Madhuca longifolia and
Pongammia pinnata in the Miyawaki plantation was analysed after three months and found that the survival of native plants under the experimental plot was 100 per cent and that of the control plot with 86.07 per cent.
Rainwater harvesting system
The excavated ponds (Fig 4) stored 32M3 water in the experimental plots and the control. This attracted cattle and browsing caused fluctuation in the physical growth of
Madhuca longifolia. The experimental and control plots were watered initially through flood irrigation. The plots absorbed more water and supported the plant growth. The Modified Miyawaki plantation aimed to create a self-sustaining ecosystem that could thrive without human intervention (
Miyawaki, 2004). In this research, the potential of native plants in carbon sequestration was investigated with in-built rainwater harvesting structures. An ancient practice rainwater harvesting is still used for flood and drought risk mitigation with environmental and social benefits which links them to the Sustainable Development Goals (
Raimondi, 2023). These structures prevented surface runoff, soil loss and increased groundwater storage levels. The distributed rainfall significantly improved soil water content and plant morphology, similar to the result obtained by
Tadros, (2021).
Soil amelioration
Chikkaraju et al., (2020) described the soil of SRM CAS as having limitations such as poor drainage, gravel, calcareousness and heavy clay content. The authors suggested that the use of organic fertilisers can improve the organic matter content as well as carbon. The practice of soil amelioration is common across all Miyawaki plantations and decomposition and composted coco-peat and paddy husk provide Nitrogen, phosphorous, potassium, micronutrients and fibre that increase the water-holding capacity and porosity. The high survival percentage of the native trees planted confirmed the quick adaptability (
Miyawaki, 1992). Soil regeneration: In the case of damaged topsoil, soil amelioration was achieved by mixing the top 20 to 30 centimetres of the soil with local organic matter such as leaf litter, mowed grass etc. (
Miyawaki, 1989).
Traditional bio-fertiliser-panchagavya
The Bio-fertiliser (Fig 5) had qualitative microbial activities in the soil. In forest modelling, the inclusion of eco-accommodating items like panchagavya effectively acts on the soil as well as plants and biodegradable (
Ponmanickam, 2023). Bacillus sp. and growth-promoting properties like P, Zn, K solubilisation, IAA and siderophore production showed bio-control action against potential plant pathogens (
Ram, 2022). The panchagavya bio fertiliser plant growth-enhancing fermented liquid (
Ponmanickam, 2023) applied enhanced microflora and stimulated the plant’s growth.
Mulching
Mulching with paddy straw (Fig 6) enhanced moisture conservation, weed control, improved organic matter content and enhanced earthworm multiplication.
Progression of Native trees planted in SRM Miyawaki plantation
The growth of Native plants (Fig 7) in the experimental plots with close spacing resulted in higher growth in 29 months than the control plots with normal spacing (Table 1). Biometric evaluation
(Goveanthan et al., 2019) height and girth of Afforested Plantation was evaluvated every three months from the date of planting.
The average height and girth of native tree species were measured every 3rd month of the study period
The average height (Fig 8) of
Syzygium cumini reached 5.4 meters over 29 months which was comparatively higher than
Milletia pinnata and
Madhuca longifolia and three native plants in control. Due to cattle browsing, the height of the
Milletia pinnata decreased intermittently and recovered. The average height of all three species in the control plots was relatively less than in the experimental plots.
The average girth (Fig 9) of three species planted in experimental plots and in control was measured and the results indicated higher girth in the experimental plots than the control. The girth of
Pongammia pinnata reached the maximum of 49 cm which was the highest compared to the other two species where
Madhuca longifolia recorded the lowest girth measured. Physical growth parameters of native trees:
Goveanthan et al., (2019) found that
Pongamia pinnata recorded 2.97 and 35.68 mm girth in 30 months whereas in the current research, the height of the tree reached 5.31 meters and 119 cm girth. This enlightened effect might be due to the trees benefiting from each other through, the mycorrhizal network, root exudates, plant growth-promoting rhizobacteria enriched by leaf litter and the micro rain-water harvesting system of this modified Miyawaki system.
Madhuca longifolia is a fast-growing tree and reached 4.52 meters in 29 months. The same was confirmed by
Shams et al., (2024) that the higher doses of organic inputs correlates positively with the physiological parameters of the crop.
Distribution of rainfall
The high rainfall recorded was due to the cyclonic storms that occurred during the study period from 2022 to 2024. Soil moisture and the optimum temperature were maintained throughout the project period (Fig 10). The rainwater stored in the micro rainwater harvesting ponds increased the seepage of water and maintained the optimum moisture of the soil, enhancing plant growth and carbon content of the soil. In addition, the bulk density of the soil was reduced.
Despite the bulky soil with poor drainage at the SRM CAS farm, the native plants in close spacing,
i.e., four plants in one square metre, soil amendment resulted in 84% higher growth parameters such as height and girth compared to the plants in the control plot.
Khoirunnisak et al., (2024) suggests that the utilization of organic matter can improve soil aggregation, thus increasing porosity and available water capacity.
The carbon content of the soil
The carbon content of the soil in the study area was estimated every three months and the results indicated that the carbon content increased positively (Fig 11).
Mycorrhiza network
The microscopic analysis of the root samples of
Syzygium cumini,
Madhuca longifolia and
Pongammia pinnata showed the presence of mycorrhiza (Fig 12). Similar to the natural forest the mycorrhiza connected all three species planted in the experimental plots R1, R2 and R3. Mycorrhizal fungi (AMF) are productive and establish comprehensive symbiotic connections with plants and are a
viable option for sustainable agroforestry
(Boyno et al., 2024). The presence of a mycorrhizal network has connected all three native species and exchanged nutrients and water similar to the forests. In addition, the mycorrhiza increased the phosphorous content in the soil. Mycorrhizal fungi (AMF) are productive and established comprehensive symbiotic connections with plants are a
viable option for sustainable agroforestry
(Boyno et al., 2024). The mycorrhiza is a potential contributor to soil organic matter
(Matos et al., 2022). The native plants chosen for this study were known to form symbiotic relationships with ecto and endo mycorrhizae (Fig 11). The results of this research was similar to
Balasubramanian, (2024) in terms of organic inputs and Arbuscular mycorrhiza application. There are significant difference in soil bulkiness, soil carbon and pH when treated with farm yard manure and vermicompost
(Singh et al., 2024).
Total biomass produced in Miyawaki plantation
Biomass accumulation/The Miyawaki forest concept involves creating small, dense, native forests. In Tamil Nadu, India, initiatives have been taken to establish Miyawaki forests to combat deforestation and promote biodiversity. These forests typically consist of native species planted close together to accelerate growth and create a self-sustaining ecosystem. The CO
2 absorbed from the atmosphere is assimilated into both Above Ground Biomass and Below Ground Biomass (Table 2). The capacity of the tree to sequester carbon increases as it matures, making them more efficient in absorbing CO
2 and store as carbon sinks. Apart from carbon captured by the trees, paddy straw, farm yard manure, tree leaf litter and mycorrhizal network enhanced soil carbon. The decomposition of leaf litter and root exudation favoured the growth of soil microbes. Additionally, these forests can serve as a recreation and oxygen-rich environment for local communities, promoting environmental awareness and contributing to the overall ecological balance.
The average carbon sequestration in the trees was estimated after 29 months. Based on the average height and girth of the native trees, the carbon captured was calculated and the result indicated that the maximum carbon by
Madhuca longifolia (250532.71 Kg) and the minimum of 10649.2 Kg by
Syzygium cumini (Table 2). The author suggests that the low carbon content in the soil can be increased with the application of higher organic matter coir pith, FYM and crop wastes coincides with the current research where fermented coco-peat, FYM, paddy straw, vermicompost and panchagavya. These organic manures release organic acids during decompositionand enrich the soil with available nutrients for plant uptake
(Sabareeshwari et al., 2024).
The pros of miyawaki afforestation
The potential benefits of Miyawaki plantations lie in soil regeneration, soil fertility, biodiversity and mitigating effects of climate change. This inexpensive and quick establishment of degraded land creates green spaces in urban areas, allowing people to relax and enjoy nature. Good management practices boosts soil carbon-storing capacity and increase soil fertility by enhancing nutrient availability to plants and microbial populations in the soil (
Chahal, 2020).
