Perbandingan Sistem Budidaya Kopi Terhadap Keanekaragaman Vegetasi dan Stok Karbon Tanah Guna Mendukung Mitigasi Perubahan Iklim

Abstract

Perubahan iklim menjadi salah satu tantangan di dalam pengelolaan sistem pertanian, termasuk budidaya komoditas kopi arabika yang sangat dipengaruhi oleh kondisi lingkungan. Sistem agroforestri berbasis kopi dinilai memiliki potensi dalam menjaga keanekaragaman vegetasi, memperbaiki kondisi mikroklimat, dan mendukung penyimpanan karbon tanah. Penelitian ini bertujuan untuk menganalisis perbedaan keanekaragaman vegetasi dan stok karbon tanah antara sistem agroforestri dan non-agroforestri dalam budidaya kopi, menganalisis hubungan indeks keanekaragaman jenis dengan stok karbon tanah, menganalisis pengaruh indeks keanekaragaman jenis terhadap stok karbon tanah, serta mengkaji potensi sistem budidaya kopi guna mendukung mitigasi perubahan iklim. Penelitian dilaksanakan pada lahan petani anggota Koperasi Produsen Kopi Mandalagiri, Kecamatan Cikajang, Kabupaten Garut. Pengambilan data dilakukan pada enam plot, yaitu tiga plot agroforestri dan tiga plot non-agroforestri. Data vegetasi dianalisis menggunakan indeks keanekaragaman Shannon-Wiener, indeks dominansi, indeks kekayaan jenis, dan indeks kemerataan. Data tanah dianalisis melalui bobot isi, C-organik, N-total, dan stok karbon tanah. Analisis data dilakukan menggunakan uji independent sample t-test, uji korelasi, dan regresi linear sederhana. Hasil penelitian menunjukkan bahwa keanekaragaman vegetasi pada sistem agroforestri cenderung lebih tinggi dibandingkan non-agroforestri, tetapi tidak berbeda nyata secara statistik. Stok karbon tanah pada sistem non-agroforestri dan agroforestri juga tidak berbeda nyata. Hubungan antara keanekaragaman vegetasi dan stok karbon tanah tergolong positif sedang antar perlakuan, sedangkan C-organik dan N-total memiliki hubungan yang lebih kuat dengan stok karbon tanah. Hasil regresi menunjukkan bahwa indeks keanekaragaman jenis memiliki arah pengaruh positif terhadap stok karbon tanah, tetapi belum berpengaruh nyata terhadap penambahan stok karbon tanah. Sistem agroforestri berbasis kopi tetap memiliki potensi dalam mendukung mitigasi perubahan iklim, terutama melalui peningkatan kompleksitas vegetasi dan stabilisasi mikroklimat.

Climate change has become one of the challenges in the management of agricultural systems, including the cultivation of arabica coffee, a commodity that is strongly influenced by environmental conditions. Coffee-based agroforestry systems are considered to have potential in maintaining vegetation diversity, improving microclimatic conditions, and supporting soil carbon storage. This study aims to analyze the differences in vegetation diversity and soil carbon stock between agroforestry and non-agroforestry systems in coffee cultivation, to analyze the relationship between the species diversity index and soil carbon stock, to analyze the effect of the species diversity index on soil carbon stock, and to examine the potential of coffee cultivation systems in supporting climate change mitigation. The research was conducted on the land of farmers who are members of the Mandalagiri Coffee Producers Cooperative, Cikajang District, Garut Regency. Data collection was carried out on six plots, consisting of three agroforestry plots and three non-agroforestry plots. Vegetation data were analyzed using the Shannon-Wiener diversity index, dominance index, species richness index, and evenness index. Soil data were analyzed based on bulk density, organic carbon (C-organic), total nitrogen (N-total), and soil carbon stock. Data analysis was performed using the independent sample t-test, correlation test, and simple linear regression. The results showed that the vegetation diversity in the agroforestry system tended to be higher than in the non-agroforestry system, but the difference was not statistically significant. Soil carbon stock in the non-agroforestry and agroforestry systems also did not differ significantly. The relationship between the vegetation diversity and soil carbon stock was classified as moderately positive across treatments, whereas C-organic and N-total showed stronger relationships with soil carbon stock. The regression results indicated that vegetation diversity had a positive direction of influence on soil carbon stock, but it did not yet have a significant effect on the increase of soil carbon stock. Coffee-based agroforestry systems still hold potential in supporting climate change mitigation, particularly through increasing vegetation complexity and stabilizing the microclimate.