The effect of liquid bio-organic fertiizer on the productivity of ironwood (Eusideroxylon zwageri) leaf biomass

Ironwood (Eusideroxylon zwageri) is an endemic species in East Kalimantan known as ulin by the local community. Ironwood is a protected and slow-growing species. It is essential to look for an alternative use in less period. Ironwood young leaves have been used traditionally as a decoction with diuretic and hair-blackening properties. Such usage provides an opportunity to utilize ironwood without cutting down trees. As a reason for leaves sustainability, it is necessary to stimulate the formation of leaves, one of which is to use liquid bio-organic fertilizer. This study aimed to determine the effect of liquid bio-organic fertilizer on increasing the growth and yield of young ironwood leaves in nurseries. Fifty ironwood seedlings were given 5 ml of liquid bio-organic fertilizer every month, and the other 50 seedlings were not given any fertilizer. The number of young leaves was recorded in the third and ninth months, while the young leaves were harvested in the sixth and twelfth months. This research showed that liquid bio-organic fertilizer increased height increments by up to 107.58%, diameter increment by up to 20.36%, the number of iron wood shoots up to 184.62%, and it also increased the weight of young leaves that can be harvested by up to 588.89%. There were any differences effects of liquid bio-organic fertilizer applied with and without bio-organic fertilizer on the growth and yield of young ironwood leaves. Ironwood shoots’ growth and yield by application of liquid bio-organic fertilizer are better than nonliquid bio-organic fertilizer.


Introduction
Ironwood (Eusideroxylon zwageri) is a species of tropical rainforest tree that faces regeneration difficulties.Indonesia's distribution is in South Sumatra, Bangka Belitung, and Kalimantan [1], [2].This wood is often referred to as "Iron Wood" due to its superior strength and durability, even surpassing iron.It is frequently substituted for construction materials.E.zwageri will be more robust and durable in humid and wet conditions.Consumers greatly prefer this benefit.Both the high demand for timber and its growth are time-consuming.[1], resulting in E.zwageri being listed as vulnerable on the IUCN Red List [2].This condition restricts the use of E.zwageri wood, necessitating a focus on non-timber forest products.
Frequent uses of E.zwageri non-wood forest products include fruit, flowers, and foliage.[3].These parts contain beneficial compounds for health and attractiveness.E.Zwageri leaves have antibacterial, antifungal, and anti-inflammatory properties [4], diuretic, and source of black hair.Therefore, a technique is required to accelerate the leaf growth of E.zwageri.
To accelerate the development of E.Zwageri, plant maintenance is essential.One of them involves fertilization.The objective of fertilization is to enhance the soil's nutrient availability as a growing medium for E.Zwageri.There are two methods for application: chemical and organic.Longterm application of chemical fertilizers can have numerous unanticipated consequences.For instance, productivity costs do not scale in a linear fashion, resulting in an enormous waste of mineral resources.Annually added millions of synthetic nutrients are not absorbed by plants.[5].In the meantime, organic applications can be made with plant-or animal-based fertilizers.The application of biological organic fertilizer (POH) or liquid bio-organic fertilizer can increase nutrient availability, enhance soil qualities, and stimulate plant growth and yield.[6].With the use of liquid bio-organic fertilizer, it is anticipated that E.Zwageri will grow faster.This research sought to determine the impact of bio-organic liquid fertilizer on the growth and yield of young ironwood leaves in nurseries.

Material and Methods
One hundred ironwood seedlings of 50-60 cm in height were prepared and planted in 50x50 cm polybags.Polybags are arranged at 1x1 m in the nursery.Seedlings acclimatized for one month.
Before being given treatment, all seedlings were measured for height and diameter.Fifty ironwood seedlings were given 5 ml of viscous liquid of biological organic fertilizer for each seed once a month for one year.The other 50 ironwood seedlings were not given fertilizer.The height, diameter, and number of young leaves were measured in the third and ninth months.In the sixth and twelfth months, young leaves are harvested.

Result and Discussions
The growth of E. Zwageri plants has been examined and evaluated by comparing the use of liquid bio-organic fertilizers and control (without fertilizer), as presented in Table 1.Until the twelfth month of observation, the liquid bio-organic fertilizer significantly affected the height and diameter growth of E. Zwageri seedlings.Ironwood seedlings without fertilization had an average diameter increment of 0.14 mm/month and a height increment of 1.57 cm/month.While ironwood seedlings given liquid organic fertilizer had a higher average increment, i.e., a diameter increment of 0.17 mm/month and a height increment of 3.26 cm/month.In liquid bio-organic fertilizers, nutrients are released slowly, resulting in an increase of E. Zwageri [7].Compared to chemical fertilizers, the use of bio-fertilizers substantially affects the height and diameter growth of other plant species.[8]- [10].
Observations on the growth of E. Zwageri shoots without fertilizer and using liquid bio-organic fertilizer in the third month and the ninth month can be seen in Table 2.This research showed that liquid bio-organic fertilizer increased the number of iron wood shoots up to 184.62%.Bio-organic plant growth stimulant fertilizer has a remarkable impact on soil health.[11].In the control treatment, the number of shoots on E. zwageri seedlings increased by four shoots from the third month to the ninth month.Meanwhile, the E. zwageri seedlings with the biofertilizer treatment added 11 shoots.Bio-fertilizer significantly affects the growth of young leaves and shoots of E. zwageri seedlings.
In the presence of rhizobacteria and soil bacteria, biofertilizers promote plant growth through the presence of numerous species containing living organisms that can increase the nutrient supply to the primary crop.[12].Different kinds of biofertilizers can promote the growth of plant seedlings.Beneficial microorganisms that are applied to roots, soil, and seedlings.Commonly produced biofertilizers influence the growth of Blue Green Algae (BGA) tree seedlings, mycorrhizae, phosphate solubilizers, azospirillum, rhizobium strains, and Acetobacter.[12].
The results of harvesting E. zwageri seedling leaves are presented in Table 3.The growth of E. zwageri is influenced by climate.Rainfall intensity significantly affects leaf formation [13] and moisture content [14].At the time of observation, there was a rainy climate from the sixth to the twelfth month; based on the results of harvesting E. zwageri leaves, the number increased from the sixth to the twelfth month.Liquid bio-organic increased the leaf biomass of E. Zwageri in 6 months to 588.89%.Previous research on other species, including Morus alba and M. indica, has demonstrated that liquid biofertilizer can increase leaf biomass with a harvest duration of 9 to 10 weeks.[15].Thus showing that liquid biofertilizer can increase the leaf biomass of E. Zwageri.Biofertilizers have the potential for rapid and environmentally favorable biomass production.[16].

Conclusion
This present study provided that liquid bio-organic fertilizer at a dose of 5 ml per month on ironwood seedlings can be increased the number of shoots, amount of leaf biomass, and height and diameter growth of ironwood seedlings in the nursery.This study presented that liquid bio-organic fertilizers caused nutrients to release slowly, and it increased ironwood.Besides, bio-fertilizers in this species affect growth in height and diameter compared to chemical fertilizers.The growth and yield results indicated variability in the effectiveness of each liquid bio-organic fertilizer to provide sufficient nutrition for supporting the positive growth of ironwood seedlings.Therefore, the leaf biomass treated with liquid bio-organic fertilizer showed more biomass than that control.This means liquid bio-organic fertilizer is considered to have the potential for efficient, fast biomass production and is also environmentally friendly.Further study is required to produce high quality of liquid bio-organic fertilizer for commercial purpose on their good quality and long shelf life.More reseaech on the application of liquid bio-organic fertilizer in the productivity of E. zwagery should be carry out under the field condition.

Table 1 .
Height and Diameter Ulin Growth

Table 3 .
Leaves Harvesting Results