EFISIENSI PEMANFAATAN RADIASI MATAHARI, AIR, PUPUK DAN LAHAN PADA TANAMAN SAYURAN SISTEM PERTANAMAN VERTIKAL BERMEDIA ABU VULKAN

MULYONO NITISAPTO, Prof. Dr. Ir. Azwar Maas, M.Sc.

2018 | Disertasi | DOKTOR ILMU PERTANIAN

Pemanfaatan abu vulkan sebagai media tanam memiliki kendala, yaitu cepat mengalami sedimentasi dan pengerasan apabila terkena air. Salah satu upaya untuk memperbaiki kondisi fisik dari abu vulkan yaitu dengan memanfaatkan biochar. Biochar merupakan salah satu bahan pembenah tanah yang dapat memperbaiki kualitas tanah. Abu vulkan perlu mendapat tambahan asupan unsur hara dari pupuk, dalam penelitian ini digunakan pupuk kompos sampah kota. Penelitian ini terdiri atas 5 tahap penelitian (1) Karakteristik bahan : abu vulkan, biochar dan kompos sampah kota. (2) Percobaan takaran kombinasi campuran abu vulkan, biochar dan pupuk kompos sampah kota yang optimal menghasilkan tanaman selada pada sistem pot. (3) karakteristik campuran media setelah inkubasi tanpa tanaman. (4) Efisiensi pemanfaatan air, pupuk dan lahan tanaman sayuran sistem pertanaman vertikal dan (5) Efisiensi pemanfaatan radiasi matahari tanaman sayuran sistem pertanaman vertikal. Abu Vulkan G. Kelud didominasi debu 52,24%, pasir 43,81% dan lempung 3,95% termasuk tekstur geluh debuan. Berat jenis 2,36 g.cm-3 dan berat volume 1,48 g.cm-3, porositas 37%, pori drainase cepat 9,27% dan pori drainase lambat 2,36%. Kapasitas lengas tersedia 23,12%, kemasaman (pH) aktual berharkat agak masam (6,31) dan pH potensial dengan nilai 5,38 (harkat masam). Kapasitas Penukaran Kation memiliki nilai 2,74 cmol+.kg-1 atau berharkat sangat rendah. Abu vulkan tidak mengandung bahan organik dan N total, P tersedia berharkat sedang dengan nilai 9,88 mg.kg-1, K tersedia sebesar 0,12 cmol+. kg-1 atau berharkat rendah. Bahan pembenah arang sekam padi mempunyai nilai pH (H2O) 7,07 dan nilai DHL 0,5 mS/cm. Kandungan C organik sebesar 5,71% setara dengan kandungan bahan organik 11,24%. Nilai KPK arang sekam padi 5,34 cmol(+).kg-1. Kandungan N total arang sekam 0,52%, kandungan P total 0,33% dan kandungan K total 0,96%. Pupuk organik yang digunakan adalah pupuk kompos sampah kota. Kemasaman pupuk kompos agak alkalis (8,19), tingkat kegaraman sangat rendah, KPK tinggi (22,51 cmol+.kg-1), N, P dan K total rendah. Pupuk kompos sampah kota dapat memberikan peran perbaikan sifat fisik, kimia dan biologi tanah, antara lain struktur tanah, sumber unsur hara bagi tanaman, meningkatkan aktivitas jasad renik, meningkatkan KPK. Perlakuan 100% abu vulkan tanpa arang sekam dan pupuk kompos tidak menunjukkan pertumbuhan. Perlakuan takaran terbaik di pot adalah 25% abu vulkan, 25% arang sekam, dan 50% pupuk kompos sampah kota dengan bobot hasil ekonomi 50,38 gram per tanaman. Perlakuan terbaik pada pertanaman vertikal dengan perlakuan yang sama menghasilkan berat segar konsumsi tertinggi 557 g/kolom. Efisiensi pemanfaatan air, pupuk dan lahan juga tertinggi pada perlakuan yang sama dengan nilai efisiensi air 2,2 g.kg-1, efisiensi pupuk 0,11 kg.kg-1 dan efisiensi lahan 2,0 kg.m-2. Hasil pengukuran dan perhitungan intensitas radiasi selama musim tanam (35 hari) berturut-turut sebagai berikut: musim tanam satu sebesar 400 MJ musim tanam kedua sebesar 269 MJ dan musim tanam ketiga sebesar 359 MJ. Nilai efisiensi pemanfaatan radiasi matahari tertinggi diperoleh pada musim tanam kedua sebesar 0,17 g.MJ-1, berikutnya musim tanam satu sebesar 0,11 g.MJ-1 dan terendah musim tanam ketiga sebesar 0,06 g.MJ-1.

Utilization of volcanic ash as planting media has a constraint, that is quickly experienced sedimentation and hardening when exposed to water. One effort to improve the physical condition of volcanic ash is by utilizing biochar. Biochar is one of the soil enhancers that can improve soil quality. Volcanic ash need to get additional nutrient intake from fertilizer, in this research used compost garbage city. This research consists of 5 research phases (1) Material characteristics: volcanic ash, biochar and compost of city waste. (2) Experiment of mixed dosage of volcanic ash, biochar and optimum municipal compost fertilizer produces lettuce plant in pot system. (3) characteristics of mixed media after incubation without plants. (4) Efficiency of water utilization, fertilizer and vegetable plant land of vertical cropping system and (5) Efficiency of radiation utilization of vegetable crop of vertical cropping system. Volcanic ash of Mt. Kelud is dominated by 52.24% silt, 43.81% sand and 3.95% clay including texture of silty loam. Specific gravity 2.36 g.cm-3 and Bulk Density 1.48 g.cm-3, porosity 37%, fast drainage pores 9.27% and drainage pore slow 2.36%. The available moisture capacity is 23.12%, actual acidity (pH) is slightly acidic (6.31) and potential pH of 5.38 (acidic). Cation Exchange Capacity has a value of 2.74 cmol +.kg-1 or very low. Volcanic ash does not contain organic material and Nitrogen, P is available with medium value with value 9.88 mg.kg-1, K available equal to 0,12 cmol+. kg-1 or low end. Charcoal husk materials have pH value (H2O) 7.07 and EC value 0.5 mS / cm. Content of organic C of 5.71% is equivalent to the organic matter content of 11.24%. The value of CEC of charcoal husk chaff 5.34 cmol +.kg-1. The total N content of the husk husk is 0.52%, the total P content is 0.33% and the total K content is 0.96%. The organic fertilizer used is the compost of municipal solid waste. The acidity of compost fertilizer was slightly alkaline (8,19), very low salinity rate, high CEC (22,51 cmol+.kg-1), N, P and K total were low. Municipal waste compost fertilizers can provide improved physical, chemical and biological properties of soil, including soil structure, nutrient source for plants, increasing microorganism activity, increasing CEC. Treatment 100% volcanic ash without charcoal husk and compost fertilizer did not produce. The best dosage treatment in pots is 25% volcanic ash, 25% charcoal husk, and 50% of city waste compost fertilizer with economical yield weight at 50.38 gram per plant. The best treatment on vertical croping system is the mentioned treatment with economical yield weight 500 g.column-1. Efficiency of water utilization, fertilizer and also highest land at that treatment with a water efficiency ratio of 2.2 g.kg-1, fertilizer efficiency of 0.11 kg.kg-1 and land efficiency of 2.0 kg.m-2. The results of measurement and calculation of radiation intensity during the planting season (35 days) are as follows: the first planting season with 400 MJ, the second planting season with 269 MJ and the third planting season with 359 MJ. The highest efficiency of solar radiation was obtained during the second growing season 0.17 g.MJ-1, the first growing season with 0.09 g.MJ-1 and the lowest at the third growing season with 0.06 g.MJ-1.

Kata Kunci : Charcoal husk, Curly lettuce, Municipal Waste Compost Fertilizer, Volcanic Ash, Vertical Croping System