Aplikasi Biochar Limbah Ekstraksi Bromelin Diperkaya N dan K pada Ultisol Lampung Tengah: Sifat-Sifat Kimia Tanah

Abstract

Pencucian hara intensif dan rendahnya efisiensi pemupukan merupakan tantangan utama dalam budidaya pertanian pada lahan kering perkebunan yang didominasi Ultisol. Biochar dari limbah ekstraksi bromelin (LEB) berpotensi digunakan sebagai pembawa pupuk lepas terkendali karena kestabilan karbon dan kemampuannya dalam meretensi hara. Penelitian ini bertujuan mengevaluasi pengaruh aplikasi Biochar LEB diperkaya N dan K (Biochar LEB NK) terhadap sifat-sifat kimia Ultisol lahan perkebunan nanas PT Great Giant Pineapple (GGP) Lampung Tengah. Penelitian ini dilaksanakan di lahan percobaan Plantation Group II 80A menurut Rancangan Acak Kelompok (RAK) faktor tunggal 4 taraf perlakuan, yaitu aplikasi secara alur Biochar LEB NK (0%, 50%, 100%, dan 150% dosis pupuk N dan K reguler) dengan 4 ulangan. Analisis sifat-sifat kimia tanah dilakukan setiap bulan selama 3 bulan pertama pertanaman nanas. Perlakuan berpengaruh nyata pada taraf uji 5% terhadap K dapat dipertukarkan (K-dd) pada ketiga periode pengamatan dan terhadap P-tersedia, Mg-dd, Ca-dd, Na-dd, dan Kejenuhan Basa (KB) pada periode pengamatan tertentu, serta tidak berpengaruh nyata terhadap pH, C-organik, N-total, dan Kapasitas Tukar Kation (KTK) hingga taraf uji 10%. Peningkatan K-dd dan KB cenderung linier terhadap taraf perlakuan.

Intensive nutrient leaching and low fertilizer use efficiency are major challenges in agriculture cultivation on plantation dry lands dominated by Ultisols. Biochar derived from bromelain extraction waste (BEW) has potential as a carrier of controlled release fertilizer due to its carbon stability and nutrient retention capacity. This study aimed to evaluate the application effects of BEW-biochar enriched with N and K (BEW-biochar NK) on the chemical properties of Ultisol at pineapple plantation land of PT Great Giant Pineapple (GGP), Central Lampung. The experiment was conducted at the Plantation Group II 80A field using a single factor Randomized Completely Block Design (RCBD) with four treatment levels of BEW-biochar NK (0%, 50%, 100%, and 150% of the regular N and K fertilizer doses), applied in planting rows, with four replications. Soil chemical properties were analyzed monthly during the first three months of pineapple cultivation. The treatment significantly affected exchangeable-K at all observation periods at 5% test level, and significantly affected available-P, exchangeable-Mg, -Ca, -Na, and base saturation (BS) at certain observation periods. No significant effects were observed on soil pH, organic-C, total-N, or cation exchange capacity (CEC) up to 10% test level. Increases in exchangeable-K and BS tended to be linear to the treatment levels.