Penggunaan Pot Organik dan Fungi Mikoriza Arbuskula (FMA) untuk Pertumbuhan Bibit Trembesi pada Media Tanah Bekas Tambang

Abstract

Kegiatan pertambangan memiliki dampak negatif terhadap lingkungan meliputi penurunan kesuburan tanah, perubahan komposisi fisik, kimia, dan biologi tanah yang disebabkan oleh penurunan pH dan peningkatan kandungan unsur kimia seperti Mn, Al, dan Fe. Hal ini mengakibatkan tanah kehilangan kemampuannya untuk memberikan nutrisi kepada tanaman. Oleh karena itu, diperlukan upaya rehabilitasi lahan bekas tambang, dengan menggunakan pot organik berbahan kompos yang mudah terurai. Pemberian bahan organik (BO), penggunaan mikoriza arbuskula (FMA), dan tanaman legum seperti trembesi (Samanea saman) dapat membantu meningkatkan kualitas tanah dan memperbaiki kesuburan tanah bekas tambang. Penelitian ini bertujuan untuk menganalisis kemampuan dan komposisi terbaik pot organik tersebut dalam meningkatkan pertumbuhan bibit trembesi pada media tanah bekas tambang, serta mengevaluasi simbiosis Fungi Mikoriza Arbuskula (FMA) dengan tanaman trembesi. Rancangan percobaan yang digunakan dalam penelitian dua adalah menggunakan rancangan Split-split plot dengan tiga faktor, yaitu plot utama terdiri atas inokulasi mikoriza (F1) dan tanpa inokulasi mikoriza (F0); sub plot yaitu ukuran bahan (M) terdiri dari 3 taraf (yaitu mesh 5, mesh 10 dan mesh 18); dan sub sub plot yaitu komposisi (K) yang terdiri dari 3 taraf (taraf pertama; koran 100%; kompos (bokashi) 0%; cocopeat 0%; rock phosphate 0%, taraf kedua; koran 45%; kompos (bokashi) 35%; cocopeat 15%; rock phosphate 5% dan taraf ketiga koran 15%; kompos (bokashi) 70%; cocopeat 5%; rock phosphate 10%). Satu ulangan terdiri dari 2 pot organik dan bibit trembesi, dilakukan sebanyak 5 ulangan, sehingga dibutuhkan sebanyak 180 unit pot organik dan bibit tanaman trembesi. Dilaksanakan pada oktober 2022 hingga April 2023 di Laboratorium Departemen Silvikultur, Laboratorium Departemen Agronomi dan Hortikultura IPB dan Laboratorium PT Indonesia Center Biodiversity and Biotechnology (ICBB), Bogor. Hasil pengujian penelitian pertama menunjukan bahwa interaksi K3M18, K2M10 dan perlakuan tunggal K1 menghasilkan nilai tertinggi terhadap daya serap air (203,60%), kelenturan (110,65 kg cm-2) dan kekuatan pot organik (7,15 kg cm 2). Hasil pengujian pada penelitian kedua menunjukkan bahwa perlakuan tunggal K3 menghasilkan nilai terendah terhadap C/N rasio awal (28,01%), C/N rasio akhir (19,67%), C-organik awal (27,77%) dan C-organik akhir (20,00%). Perlakuan K3 menghasilkan nilai tertinggi dan secara signifikan tidak berbeda nyata dengan perlakuan K2 terhadap kandungan P2O5 (14981,80 mg 100 g-1) dan K2O potensial (245,45 mg 100 g-1). Interaksi perlakuan K3M18 menghasilkan nilai tertinggi terhadap nutrisi N-total awal (1,14%) dan akhir pot organik (130,00%). interaksi F1K3 dan K3M18 menghasilkan nilai tertinggi terhadap parameter tinggi tanaman (46,22 cm) dan (44,48 cm), sementara interaksi K3M18 dan perlakuan tunggal F1 menghasilkan nilai tertinggi terhadap diameter tanaman (4,50 mm) dan (4,28 mm). Hasil analisis menunjukan bahwa interaksi F1K3M10 menunjukan sangat signifikan dengan hasil terbaik terhadap panjang akar (22,65 cm) dan interaksi F1K3, F1M18 dan K3M18 menghasilkan nilai tertinggi terhadap berat kering akar (0,98 g), (0,92 g) dan (0,97 g) dan total biomasa tanaman (4,09 g), (3,47 g) dan (3,23 g). Sedangkan hasil interaksi F1K3 dan K3M18 menghasilkan nilai terbaik pada parameter berat kering pucuk (3,11 g) dan (3,27 g), juga terhadap parameter nisbah pucuk akar (2,13) dan (2,30). Interaksi F1K3M18 menunjukkan kandungan klorofil tertinggi mencapai 47,98 µg g-1. Tanaman yang di inokulasi FMA (F1) menunjukkan laju transpirasi dan fotosintesis tertinggi (0,00045 mmol H2O m-2 s-1) dan (0,55339 µmol CO2 m-2 s-1). Sedangkan perlakuan tunggal K3 dan M18 masing-masing menghasilkan laju transpirasi terbaik (0,00057 mmol H2O m-2 s-1) dan (0,48555mmol H2O m-2 s-1). Selain itu, laju fotosintesis tertinggi juga terdapat pada perlakuan tunggal K3 (0,68185 µmol CO2 m-2 s-1) dan M18 (0,48555 µmol CO2 m-2 s-1). Perlakuan M18 menunjukkan kandungan nutrisi N-total tertinggi dengan nilai sebesar 3,11%, dan interaksi F1K3 menunjukan kandungan nutrisi P tertinggi mencapai 3,85%. Perlakuan tunggal F1 menunjukan hasil tertinggi terhadap kandungan nutrisi P (0,14%) dan K (1,16%), sedangkan K2 menghasilkan nilai tertinggi terhadap nutrisi P (0,16%) dan K (1,45%). Perlakuan tunggal F1 dan perlakuan interaksi K2M10 menghasilkan nilai terbaik terhadap kandungan nutrisi Ca (59% dan 0,70%) dan kandungan Mg (0,422 % dan 0,15 %).

Mining activities have negative impacts on the environment including decreased soil fertility, changes in the physical, chemical and biological composition of the soil caused by decreased pH and increased content of chemical elements such as Mn, Al and Fe. This results in the soil losing its ability to provide nutrients to plants. Therefore, rehabilitation of ex-mining land is needed, using organic pots made from biodegradable compost. The provision of BO, the use of arbuscular mycorrhiza (FMA), and legume plants such as trembesi (Samanea saman) can help improve soil quality and improve ex-mining soil fertility. This study aims to analyse the ability and the best composition of organic pots in increasing the growth of trembesi seedlings on ex-mining soil media, as well as evaluating the symbiosis of Arbuscular Mycorrhizal Fungi (FMA) with trembesi plants. The experimental design used in the second study was a split-split plot design with three factors, namely the main plot consisting of mycorrhizal inoculation (F1) and without mycorrhizal inoculation (F0), subplots were material size (M) consisting of 3 levels (i.e. mesh 5, mesh 10, and mesh 18), and subplots were composition (K) consisting of 3 levels (first level; 100% newsprint, bokashi, and compost, as well as cocopeat and rock phosphate); and subplots were composition (K) consisting of 3 levels (first level; 100% newspaper; 0% compost (bokashi); 0% cocopeat; 0% rock phosphate, second level; 45% newspaper; 35% compost (bokashi); 15% cocopeat; 5% rock phosphate, and third level 15% newspaper; 70% compost (bokashi); 5% cocopeat; 10% rock phosphate). One replicate consisted of 2 organic pots and trembesi seedlings, conducted 5 times, so 180 units of organic pots and trembesi seedlings were needed. It was conducted from October 2022 to April 2023 at the Laboratory of the Department of Silviculture, Laboratory of the Department of Agronomy and Horticulture IPB and Laboratory of PT Indonesia Center Biodiversity and Biotechnology (ICBB), Bogor. The test results in the first study showed that the interaction of K3M18, K2M10 and single treatment K1 produced the highest values for water absorption (203.60%), flexibility (110.65 kg cm-2) and organic pot strength (7.15 kg cm-2). The test results in the second study showed that the single treatment K3 produced the lowest value in the initial C/N ratio (28.01%), final C/N ratio (19.67%), initial C organic (27.77%) and final C-organic (20.00%). K3 treatment produced the highest value and was not significantly different from K2 treatment in P2O5 content (14981.80 mg 100 g-1) and potential K2O (245.45 mg 100 g-1). The K3M18 treatment interaction produced the highest N-total nutrient value at the beginning (1.14%) and end of the organic pot (130.00%). The interaction of F1K3 and K3M18 produced the highest values in plant height parameters (46.22 cm) and (44.48 cm), while the interaction of K3M18 and single treatment F1 produced the highest values in plant diameter parameters (4.50 mm) and (4.28 mm). The results of the analysis showed that the interaction of F1K3M10 showed highly significant results with the best results in root length (22.65 cm) and the interaction of F1K3, F1M18 and K3M18 produced the highest values in the parameters of root dry weight (0.98 g), (0.92 g) and (0.97 g) and total plant biomass (4.09 g), (3.47 g) and (3.23 g). While the interaction results of F1K3 and K3M18 produced the best value in the shoot dry weight parameter (3.11 g) and (3.27 g), as well as in the crown-root ratio parameter (2.13) and (2.30). F1K3M18 interaction showed the highest chlorophyll content reaching 47.98 µg g-1. Plants inoculated with FMA (F1) showed the highest transpiration and photosynthesis rates (0.00045 mmol H2O m-2 s-1) and (0.55339 µmol CO2 m-2 s-1). While the single treatments K3 and M18 respectively produced the best transpiration rate (0.00057 mmol H2O m-2 s-1) and (0.48555 mmol H2O m-2 s-1). In addition, the highest photosynthetic rate was also found in the single treatments K3 (0.68185 µmol CO2 m-2 s-1) and M18 (0.48555 µmol CO2 m-2 s-1). The M18 treatment showed the highest N-total nutrient content with a value of 3.11%, and the F1K3 interaction showed the highest P nutrient content reaching 3.85%. Single treatment F1 showed the highest results for P (0.14%) and K (1.16%) nutrients, while K2 produced the highest values for P (0.16%) and K (1.45%) nutrients. Single treatment F1 and interaction treatment K2M10 produced the best values for Ca content (59% and 0.70%) and Mg content (0.422% and 0.15%).