POTENSI BIOMASA DAN KARBON ORGAN AKAR TANAMAN KAKAO (Theobroma cacao) DI LAHAN AGROFORESTRI DESA NGLANGGERAN, KABUPATEN GUNUNGKIDUL, DIY

DEWA AYU AGUNG SURYA DEWI, Dr. Ir Ris Hadi Purwanto, M.Agr.Sc.

2015 | Skripsi | S1 KEHUTANAN

Sistem agroforestri yang dikembangkan di hutan rakyat merupakan salah satu jenis pemanfaatan lahan yang efektif sebagai penyedia kebutuhan kayu dan non kayu serta jasa lingkungan yang berpengaruh besar terhadap pengurangan emisi gas karbondioksida (CO2) melalui proses fotosintesis. Penyusunan allometrik dilakukan untuk menduga potensi biomasa, karbon dan serapan gas CO2 pada jenis tanaman kakao di lahan agroforestry Desa Nglanggeran, Kecamatan Patuk, Kabupaten Gunungkidul, DIY. Penyusunan allometrik dilakukan melalui pengambilan sampel organ akar dengan cara menggali tanah pada pohon yang sudah ditebang berdasarkan variasi ukuran diameter batang tanaman kakao dari diameter 1-30 cm. Analisis biomasa dilakukan dengan cara mengeringtanurkan sampel sampai mencapai berat kering konstan. Analisis karbon dilakukan dengan metode Walkley dan Black yaitu dengan cara diserbukkan dan kadar karbon terekstrak diukur menggunakan spektofotometer. Hasil penelitian ini menunjukkan bahwa kadar karbon akar adalah 40,04% dari berat biomasanya. Rata-rata biomasa akar dalam satu pohon sebesar 9,29 kg/pohon, rata-rata kandungan karbon akar sebesar 3,71 kg/pohon dan serapan gas CO2 pada organ akar sebesar 13,63 kg/pohon. Persamaan allometrik yang dihasilkan dengan menghubungkan antara Dbh dengan biomasa adalah Bt = 0,035 Dbh 2,325 , dan menghubungkan antara Dbh dengan kandungan karbon adalah C = 0,014 Dbh2,319 serta menghubungkan antara Dbh dengan serapan gas CO2 adalah CO2 = 0,051 Dbh 2,319 . Dari hasil inventarisasi pada 30 sampel responden pemilik hutan rakyat yang menanam kakao dengan sistem agroforestri, diperoleh rata-rata kandungan biomasa sebesar 23,26 ton/ha, rata-rata kandungan karbon adalah 10,31 ton/ha dan rata-rata serapan gas CO2 adalah 33,39 ton/ha. Penanaman kakao di hutan rakyat Desa Nglanggeran dengan sistem agroforestri perlu dikembangkan karena mempunyai prospek yang baik di masa yang akan datang

Agroforestry systems that developed in a community forest is one kind of land use that is effective as a provider of timber and non-timber needs as well as environmental services which have a great impact on reduction of carbon dioxide emissions (CO2) through photosynthesis. Allometric compilation conducted to estimate the potential of biomass, carbon and absorption of CO2 on the kind of cocoa trees on the agro-forestry area at Nglanggeran Village, Patuk District, Gunungkidul, Yogyakarta. The compilation of the allometric was done through the root sampling by digging in the soil which the trees have been cut down based on variations in the size of the cocoa plant stem diameter of 1-30 cm. The analysis of biomass is conducted by drying the sample until reaching its constant weight. The analysis of carbon is conducted with using a method of Walkley and Black that is by grinding the sample into powder and the extracted carbon content which is measured by using a spectrophotometer. The result of this research indicates that the root carbon content is 40,04% of the biomass weight. The biomass of the root in average of one tree is 9,29 kg / tree, for the carbon content of the root in average is 3,71 kg/ tree. For the absorbtion of CO2 on root organs in average is 13,63 kg/ tree. The allometric equation that generated by connecting between DBH and biomass is Bt = 0,035 Dbh 2.325, and the allometric equation by connecting between DBH and carbon content is C = 0,014 Dbh 2.319, furthermore, the allometric equation by connecting between DBH and CO2 absorption is CO2 = 0,051 Dbh 2.319. From the results of sampling on 30 private forest owners that planting the cacao on their land using the agroforestry system, has been gained an average for biomass content of 23.26 tons / ha, the average for carbon content is 10,31 tons / ha and the average CO2 absorption is 33,39 tons / ha. The cocoa cultivation with the agroforestry systems in the community forest at Nglanggeran village requires to be developed because of having a good prospect in future.

Kata Kunci : Agroforestri, biomasa, karbon, CO2, Persamaan allometrik