Performance of slow-release crab shells based on hydroxyapatite fertilizer on the growth of Cucumis sativus plants Yusuf Wibisono1,2,*, Farhan W. Daniswara1, Susi Rokhmatul Ummah1, Mochamad B. Hermanto3, Gunomo Djoyowasito3, Alfian Noviyanto4
1 Department of Bioprocess Engineering, Faculty of Agricultural Technology, Brawijaya University, Jl. Veteran Malang 65145 Indonesia-
2 MILI Institute for Water Research, Kawasan Industri Jababeka, Bekasi, Indonesia 17530
3 Department of Agricultural and Biosystems Engineering, Faculty of Agricultural Technology, Brawijaya University, Jl. Veteran Malang 65145 Indonesia-
4 Nano Center Indonesia, Jl. PUSPIPTEK Tangerang Selatan, Banten 15314 Indonesia-
* Corresponding author: Y_Wibisono[at]ub.ac.id
Abstract
The crab shell is the impact resulting from the high demand for crab commodities. Crab shells are obtained apart from waste, but they have several benefits. Such as the benefit of calcium content. Calcium in crab shells can be used in the manufacture of hydroxyapatite. The adsorption ability of hydroxyapatite can be utilized in the manufacture of slow-release fertilizer (SRF). SRF can release nutrients slowly and minimize the impact of environmental damage. In this study, SRF was made by mixing hydroxyapatite with inorganic fertilizers. The steps are cleaning and drying the crab shells, then crushing using a ball mill and calcining at 1000C. The calcium precursor (CaO) also known as hydroxyapatite powder was synthesized using a wet chemical precipitation method with calcination treatment at 600C. Furthermore, the encapsulation process between inorganic fertilizer and hydroxyapatite powder is carried out. The SRF produced was applied to cucumber to observe plant height, stem diameter, number of leaves, number of fruits, total fruit, and soil pH which was measured every 7 days. Observations were made with 5 treatments and 3 repetitions, namely treatment without fertilizer, ZA fertilizer, ZA-HA fertilizer, Urea fertilizer, and Urea-HA fertilizer. The observational data was analyzed using Randomized Block Design (RBD). The best results from all observation parameters are shown in the treatment with ZA-HA fertilizer. The usage of fertilizer containing hydroxyapatite is thought to be more efficient and gave a better result than using single fertilizer for plant growth.
