| dc.contributor.advisor | Putra, Heriansyah | |
| dc.contributor.advisor | Erizal | |
| dc.contributor.advisor | Nasrullah, Nizar | |
| dc.contributor.author | S, Genesis Lorenzo | |
| dc.date.accessioned | 2026-08-04T10:43:09Z | |
| dc.date.available | 2026-08-04T10:43:09Z | |
| dc.date.issued | 2026 | |
| dc.identifier.uri | http://repository.ipb.ac.id/handle/123456789/177054 | |
| dc.description.abstract | Bencana longsor di wilayah tropis dengan curah hujan tinggi merupakan ancaman serius yang umumnya dimitigasi melalui pendekatan rekayasa bio-teknik menggunakan tanaman vetiver (Chrysopogon zizanioides (L.) Roberty). Meskipun perakarannya efektif berfungsi sebagai tulangan tanah hidup, penerapan metode ini memiliki keterbatasan teknis, yaitu terdapatnya jeda waktu rentan erosi antara fase awal penanaman hingga terbentuknya sistem perakaran yang kuat. Dalam mengatasi kesenjangan tersebut, penelitian ini bertujuan menganalisis respons pertumbuhan morfologi dan distribusi biomassa akar akibat induksi stimulan biologis (mikoriza dan Plant Growth-Promoting Rhizobacteria / PGPR) serta kimiawi (Indole-3-Butyric Acid / IBA), mengevaluasi besaran peningkatan kohesi tanah dan efisiensi biomekanis akar, serta menentukan potensi akselerasi waktu pencapaian target kekuatan tanah sebagai solusi mitigasi longsor jangka pendek. Eksperimen ini dirancang menggunakan Rancangan Acak Kelompok (RAK) pada kolom tanah terkontrol berupa pipa yang ditempatkan di lingkungan terbuka. Evaluasi parameter mekanika tanah kemudian dilakukan melalui uji geser langsung (direct shear test) pada interval pengamatan 30, 45, 60, 75, dan 90 Hari Setelah Tanam (HST). Hasil penelitian menunjukkan bahwa aplikasi stimulan secara nyata memodulasi arsitektur perakaran vetiver tanpa mengganggu keseimbangan fisiologis rasio tajuk-akar, sekaligus meningkatkan kohesi tanah total (??) dan kohesi akar (????') secara substansial. Seluruh perlakuan stimulan terbukti memberikan peningkatan parameter kohesi akar (????') yang jauh melampaui tanaman tanpa perlakuan (kontrol) yang memiliki efisiensi kohesi dasar sebesar 9,56 kPa per satuan rasio massa akar. Perlakuan Mikoriza memberikan efisiensi perkuatan kohesi akar (????') tertinggi sebesar 23,11 kPa, atau meningkat 2,42 kali lipat dibandingkan kontrol . Perlakuan hormon IBA menempati peringkat kedua dengan efisiensi kohesi akar (????') sebesar 22,02 kPa, atau meningkat 2,30 kali lipat terhadap kontrol. Sementara itu, perlakuan PGPR memberikan efisiensi kohesi akar (????')sebesar 19,38 kPa, atau meningkat 2,03 kali lipat dibandingkan kontrol. Pada akhir pengamatan (90 HST), kohesi tanah perlakuan berstimulan konsisten mencapai 14–15 kPa, jauh melampaui tanaman kontrol yang melandai di bawah 9 kPa. Perlakuan Mikoriza terbukti mengakselerasi stabilisasi lereng, di mana kapasitas perkuatan tanah kontrol umur 90 HST mampu disamai hanya dalam waktu 45 HST. Pemangkasan jeda waktu (temporal lag) ini efektif meminimalkan risiko kerentanan awal lereng sebagai solusi mitigasi jangka pendek rekayasa biogeoteknik. | |
| dc.description.sponsorship | Landslides in tropical regions with high rainfall are a serious threat that is generally mitigated through a bio-engineering approach using vetiver grass (Chrysopogon zizanioides (L.) Roberty). Although its root system effectively functions as living soil reinforcement, the application of this method has technical limitations, namely, the presence of a time window vulnerable to erosion between the initial planting phase and the formation of a strong root system. To address this gap, this study aims to analyze the response of root morphological growth and biomass distribution resulting from the induction of biological stimulants (mycorrhizae and plant growth-promoting rhizobacteria (PGPR)) and chemical stimulants (Indole-3-Butyric Acid / IBA), to evaluate the extent of improvement in soil cohesion and root biomechanical efficiency, and to determine the potential for accelerating the time required to achieve target soil strength as a short-term landslide mitigation solution. This experiment was designed using a Randomized Block Design (RBD) on controlled soil columns in the form of pipes placed in an open environment. Evaluation of soil mechanical parameters was then conducted via direct shear tests at observation intervals of 30, 45, 60, 75, and 90 Days After Planting (DAP). The results of the study indicate that the application of the stimulant significantly modulates the root architecture of vetiver without disrupting the physiological balance of the shoot-to-root ratio, while substantially increasing total soil cohesion (??) and root cohesion (????'). All stimulant treatments were found to increase the root cohesion parameter (????') to levels far exceeding those of untreated plants (controls), which had a baseline cohesion efficiency of 9.56 kPa per unit root mass ratio. The mycorrhiza treatment yielded the highest root cohesion efficiency (????') at 23.11 kPa, representing a 2.42-fold increase compared to the control. The IBA hormone treatment ranked second with a root cohesion efficiency (????') of 22.02 kPa, representing a 2.30-fold increase compared to the control. Meanwhile, the PGPR treatment yielded a root cohesion efficiency (????') of 19.38 kPa, representing a 2.03-fold increase compared to the control. At the end of the observation period (90 HST), the soil cohesion of the stimulated treatment consistently reached 14–15 kPa, far exceeding that of the control, which declined to below 9 kPa at the same time. The mycorrhizal treatment accelerated slope stabilization, as the soil reinforcement capacity of the 90-HST-old control was matched in only 45 HST. Reducing this temporal lag effectively minimizes the risk of initial slope vulnerability as a short-term biogeotechnical mitigation solution. | |
| dc.language.iso | id | |
| dc.publisher | IPB University | id |
| dc.title | Stimulasi Perakaran Vetiver untuk Meningkatkan Kuat Geser Tanah dalam Usaha Mitigasi Longsor | id |
| dc.title.alternative | Vetiver Root Stimulation to Increase Soil Shear Strength for Landslide Mitigation | |
| dc.type | Tesis | |
| dc.subject.keyword | Bio-engineering | id |
| dc.subject.keyword | Kohesi | id |
| dc.subject.keyword | stabilitas lereng | id |
| dc.subject.keyword | Stimulan akar | id |
| dc.subject.keyword | Vetiver | id |
| dc.subtype | Theses | |
