Model berbagi sumberdaya (Resources Sharing) dalam sistem agroforestri

SURYANTO, Priyono, Prof.Dr.Ir. Tohari, M.Sc

2005 | Tesis | S2 Agronomi

Faktor penentu keberhasilan agroforestri salah satunya pemahaman sistem berbagi sumberdaya (cahaya, hara dan air). Penelitia n ini dilakukan untuk mengetahui parameter kunci sistem berbagi sumberdaya, model kompetisi pohonpohon, respon tanaman semusim dan model berbagi sumberdaya antara pohon dan tanaman semusim. Penelitian ini dilakukan pada sistem agroforestri pola trees along border/TAB) dan lorong (alley cropping/AC). Interaksi pohon-pohon didasarkan pada indeks kompetisi. Respon tanaman semusim (jagung) diambil pada 6 sistem agroforestri (3 TAB dan 3 AC) yang dibagi menjadi 3 zona dan sebagai kontrol kondisi terbuka. Penga matan dilakukan terhadap luas daun; bobot kering; status air tanaman; kandungan klorofil; kehijauan daun; panjang akar; luas akar dan kandungan N,P,K pada daun, akar serta total tanaman. Analisis tanaman jagung menggunakan General Linear Model. Apabila terjadi perbedaan diantara rata -rata perlakuan maka dilakukan uji lanjut dengan DMRT taraf 5%. Hasil penelitian menunjukkan bahwa kompetisi pohon-pohon mempunyai persentase berbagi sumberdaya paling tinggi yaitu akasia -sonokeling 91,7 % (IKO =5,1444e-0,0942dbh, PKK=0,4268e-0,0797dbh); diikuti jati-sonokeling 87,87% (IKO = 4,6417e-0,0794dbh,PKK=0,386e-0,0794dbh); jati-mahoni 85,71% (IKO = 3,6659e-0,05 dbh ,PKK=0,188e-0,05dbh); jati-akasia 67,74% (IKO =1,9921e-0,0457dbh,PKK=0,0932e- 0,0457dbh) dan mahoni-sonokeling 66,53% (IKO = 11,585e-0,1259dbh,PKK=1,9921e- 0,0457dbh). Hasil analisis tanaman jagung menunjukkan luas daun, berat kering (daun,batang, biji 100 buah, total biji, tongkol dan klobot) pada zona 2 dan 3 tidak terdapat perbedaan yang nyata namun keduanya berbeda nyata dengan zona 1. Urutan penangkapan sumber energi paling bagus yaitu zona 3, 2 dan 1. Status nutrisi dan kadar air pada zona 1, 2 dan 3 tidak berbeda nyata, sedangkan sistem perakaran terdapat perbedaan antar zonasi pada variabel: berat akar kedalaman 10-20 cm; panjang akar kedalaman 0-10-20 cm dan luas permukaan akar 0-10 cm dan 20-30 cm. Sistem berbagi sumberdaya dalam agroforestri awal menunjukkan bahwa zona 1 (pemanfaatan energi didominasi oleh pohon/tanaman semusim sangat tertekan); zona 2 (tanaman semusim tertekan) dan pada zona 3 (tanaman semusim optimal). Skenario untuk peningkatan penangkapan dan pemanfaatan cahaya dari zona 1 ke 2, atau zona 2 ke 3 melalui pruning tajuk sedangkan dari zona 1 ke zona 3 dapat dilakukan melalui polarding dan commercial thinning sebagai skenario tindakan sistem di atas tanah. Skenario untuk peningkatan penyerapan sumberdaya pada sistem di bawah tanah dapat dilakukan melalui pruning akar pohon penyusun dengan jarak 2 m dari baris pohon pada kedalaman minimal 30 cm.

The success of agroforestry depends on the understanding of resources sha ring systems (light, nutrient and water). Research was conducted to investigate key parameter of resources sharing; trees competition models, growth of annual crops, and resources sharing model between trees and annual crops. Research was conducted on trees along border/TAB and alley cropping/AC to estimate trees competition index. Response of annual crops (maize) was taken on 6 agroforestry systems (3 TAB and 3 AC) divided into 3 zones with open area as control. Observed parameter were leaf area, dry weight, plant water status, chlorophyll content, leaf greenness, length and area of root surface, and the N,P,K contents of leaf, root and a whole plant. General linear model was used to analyze the maize parameters. Further significances were then analyzed by DMRT 5%. The highest resources sharing percentage was found on sonokeling-acacia trees competition 91,7% (optimum competition index/OCI=5,1444e-0,0942dbh, competition capability decreasing/CCD=0,4268e-0,0797dbh); followed by teaksonokeling 87,87% (OCI =4,6417e-0,0794dbh , CCD =0,386e-0,0794db); teak-mahogany 85,71% (OCI =3,6659e-0,05dbh, CCD=0,188e-0,05dbh); teak-acacia 67,74% (OCI 1,9921e-0,0457dbh , CCD=0,0932e-0,0457dbh); and the lowest was mahoganysonokeling 66,53% (OCI = 11,585e-0,1259dbh, CCD=1,9921e-0,0457dbh). There were no significance found on the respons of the area of leaf, dry weight (leaf, stem, 100 grains of seeds, total of seeds, stalk) of maize on zone 2 and 3; while that of zone 1 was significant. Nutrient status and water content were not significant by difference at zone 1, 2 and 3. Rooting system have significant among zone exactly at root weight 10-20 cm soil depth, root length at 0-10-20 cm soil depth and area of root surface at 0-10 cm and 20-30 cm soil depth. Resources sharing in agroforestry active shown that zone 1 (energy resources is dominated by trees/annual crops very stressed), zone 2 (annual crops stressed) and zone 3 (annual crops optimal). The enhancement of light trapping and their use was done by canopy pruning to increase the light status from zone 1 to 2, or 2 to 3; while that of 1 to 3 was done by pollarding and commercial thinning; as a scenario for aboveground systems treatment. The enhancement of belowground uptake was done by root pruning on trees at 2 m distance fr om trees rows at 30 cm depth.

Kata Kunci : Agroforestri,Cahaya,Hara dan Air,agroforestry, resouces sharing, competition index