Source: SEAMEO BIOTROP's Research Grant | 2021
The purpose of this study is:
1. Comparing and analysing seedball formulation
2. Analyzing the effectiveness of direct seeding and seedball techniques for recalcitrant, orthodox and cover crop seeds
3. Analysing survival rate and germination rate of the plants with direct seeding and seedball planting method
4. Analysing factor that influence the succesfull of direct seeding and seedball planting method at post mining area.
5. Analysing the influence of manure to germination rate which plants with direct seeding planting method.
The results of this studies are expected to be used as material in determining the post- mining land reclamation method and determining the suitable and effective plant species through direct seeding and seedball methods. Planting with direct seeding and seedball methods is expected to reduce planting costs and accelerate the reclamation program for ex-mining land in Indonesia, especially limestone mining.
The results of this study indicate that Merbau (Intsia bijuga), Ketapang (Terminalia catappa), and Jackfruit (Artocarpus heterophyllus) species are adaptive species to be planted in post-limestone mining areas using direct seeding method. Meanwhile, Jackfruit (Artocarpus heterophyllus), Gmelina (Gmelina arborea), and Merbau (Intsia bijuga) species are adaptive species to be planted in post-limestone mining areas using the seedball method.
The results of this study also indicate that direct sowing can be a viable alternative method of revegetation in ex-mining sites for certain recalcitrant and orthodox plant species. The most promising species for use are those that have at least one (but preferably more than one) of the following characteristics:
- Easily obtainable seeds (available in large quantities and for a long time);
- High seed viability and storage potential;
- Fast and consistent germination;
- Large seed size (>5 g) and large seedling size after germination for situations where there is significant weed growth;
- Deep root extension for situations where there is significant growth of shallow rooted weeds;
- High growth rate potential;
- Low sensitivity to competition;
- Wide tolerance to a wide range of light conditions—some shade tolerance may be advantageous in many situations.
However, that the characteristics of these species, where they should be sown directly and the most appropriate time for sowing must be considered, particularly in relation to the season at planting time and the conditions of land openness. This is to avoid environmental conditions that are too hot or scorching for plant growth and the need for water for plant growth. Experiments to assess the growth performance of recalcitrant and orthodox species under various conditions (especially different light environments) and different seasons can help in identifying species that are more adaptive to water stress and microenvironmental conditions (microclimate).
From the cost analysis, planting with direct seeding has a lower cost than using seedball. Optimal results can be obtained from a combination of low cost direct seeding and higher cost but more reliable seedling planting. The seedling success recorded in this trial basically indicates the minimum success that can be achieved using direct sowing. Maintenance in such a method must be very carefully considered, this is to increase the viability and growth of tree seedlings as a commitment to reforesting ex-mining land.
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