APLIKASI MIKORIZA DAN LIMBAH PADAT KELAPA SAWIT SERTA PENGURANGAN DOSIS PUPUK NPK PADA KELAPA SAWIT

Abstract

Budidaya kelapa sawit dilakukan secara monokultur dan menggunakan bahan kimia pupuk maupun herbisida secara terus menerus yang berdampak pada kesehatan tanah. Salah satu upaya mengurangi pupuk kimia adalah penggunaan pupuk hayati seperti fungi mikoriza arbuskular (FMA) dan pupuk organik yang berasal dari limbah padat kelapa sawit seperti tandan kosong, kompos mapun biochar. Penelitian ini bertujuan mengetahui (i) pengaruh kombinasi dosis mikoriza, berbagai limbah padat kelapa sawit dan pengurangan dosis pupuk NPK terhadap perbaikan sifat biologi, kimia, fisika tanah, tinggi tanaman, kandungan hara daun dan klorofil daun kelapa sawit, (ii) pengaruh aplikasi Mikoriza dengan berbagai limbah padat kelapa sawit terhadap efisiensi pemupukan, (iii) jenis spora FMA tanah perlakuan, spora FMA lokal dan spora FMA komersil. Penelitian menggunakan rancangan acak kelompok faktorial dengan 3 faktor dan 3 ulangan. Faktor pertama adalah dosis mikoriza yaitu 0, 250 g, dan 350 g, faktor kedua yaitu bahan organik tandan kosong kelapa sawit, kompos, biochar, dan faktor ketiga adalah dosis pupuk NPK 12:12:17 100 % dosis dan 50 % dosis rekomendasi. Parameter pengamatan biologi tanah yaitu tingkat kolonisasi akar mikoriza, jumlah spora mikoriza, serta populasi bakteri dan fungi, sedangkan pengamatan sifat kimia tanah meliputi pH, C-organik, kadar N, P, K, dan KTK tanah. Parameter fisika tanah dilakukan terhadap stabilitas agregat tanah. Pengamatan pertumbuhan tanaman meliputi tinggi tanaman, analisis hara N, P, K pada jaringan daun, dan kandungan klorofil daun. Data yang diperoleh dari penelitian dianalisis secara statistik menggunakan uji Analysis of Variance (ANOVA). Jika hasil uji F pada taraf a=5% menunjukkan adanya pengaruh signifikan, maka analisis dilanjutkan dengan uji Beda Nyata Jujur (BNJ) pada taraf 5%. Hasil penelitian menujukkan bahwa tidak terdapat pengaruh kombinasi faktor perlakuan terhadap kolonisasi akar, jumlah spora, total populasi mikrob, kandungan kimia tanah berupa N, P tersedia, K, C-organik, pH, KTK, tinggi tanaman, kandungan klorofil daun, kandungan hara daun, serta kemantapan agregat tanah. Pemberian dosis mikoriza 250 g berpengaruh nyata terhadap tingkat kolonisasi akar oleh FMA yaitu sebesar 16,55% dan terhadap kandungan klorofil daun sebesar 66,9 SPAD. Pemberian bahan organik kompos berpengaruh nyata terhadap jumlah spora FMA yaitu sebesar 614,16 spora/50 g tanah. Pemberian pupuk dosis 50% memberikan respon tinggi tanaman, kandungan klorofil daun, dan hara daun yang sama dengan dosis 100%. Identifikasi molekuler menunjukkan isolat FMA tanah perlakuan adalah Acaulospora koreana/Acaulospora mellea, isolat FMA lokal adalah Scuttelospora cerradensis/Dentiscutata colliculosa dan Acaulospora longula, dan isolat FMA komersil adalah Rhizophagus intraradices.

Oil palm cultivation is carried out in monoculture using chemicals fertilizer and herbicide which is carried out continuously and has an impact on soil health. One effort to reduce the chemical fertilizers is by using biological fertilizers such as arbuscular mycorrhiza fungi (AMF) and organic fertilizers derived from solid palm oil waste such as empty fruit bunches, compost and biochar. This research aims to determine (i) the effect of combintaion mycorrhizal dose with palm oil solid wastes and reducing the dose of NPK fertilizer on improving biological, chemical, and physical soil properties, plant height, leaf nutrient content and chlorophyll of oil palm leaves, (ii) the effect of mycorrhiza application with various palm oil solid waste on fertilization efficiency, (iii) find out the type of AMF spores in the treated soil, local AMF spores and commercial AMF spores. The study used a factorial randomized block design with 3 factors and 3 replications. The first factor is the mycorrhizal dose, namely 0, 250 g and 350 g, the second factor is the organic material of empty palm fruit bunches, compost and biochar and the third factor is the NPK 12 fertilizer dose, namely 100% of the recommended dose and 50% of the recommended dose. The soil biological observation parameters were the level of mycorrhizal root colonization, the number of mycorrhizal spores, bacteria and fungi populations, while observations of the soil chemical properties include pH, organic carbon, N, P, K content, and soil CEC. The soil physical parameters were carried out on the stability of soil aggregates. Observation of plant growth includes plant height, N, P, K nutrient analysis in leaf tissue, and leaf chlorophyll content. The data obtained from the study were analyzed statistically using the Analysis of Variance (ANOVA) test. If the results of the F test at the a = 5% level indicated a significant effect, then the analysis was continued with the Honestly Significant Difference (HSD) test at the 5% level. The results of the study showed that there was no significant effect of the combination of treatment factors on root colonization, spore count, total microbial population, soil chemical properties of N, available P, K, organic C, pH, CEC, plant height, leaf chlorophyll content, leaf nutrient content (N, P, K), and soil aggregate stability. The application of 250 g mycorrhizal had a significant effect on the level of AMF root infection, which reached 16,55 % and on leaf chlorophyll content which was 66,9 SPAD. Compost organic matter had a significant effect on the number of AMF spores, which was 614,16 spores/50 g of soil. 50% dose of fertilizer gives the same response in plant height, leaf chlorophyll content, and leaf nutrients as a 100% dose. Molecular identification revealed Acaulospora koreana/Acaulospora mellea in treated soil, Scutellospora cerradensis/Dentiscutata colliculosa, and Acaulospora longula in local inoculum, and Rhizophagus intraradices in commercial inoculum.