Penerapan Metode VESS (Visual Evaluation of Soil Structure) pada Lahan Agroforestri dan Hutan Alam

Abstract

Konversi hutan menjadi lahan non-hutan seperti pertanian dan perkebunan dapat menurunkan kualitas fisik tanah. Agroforestri menjadi alternatif pengelolaan lahan yang memberikan manfaat ganda, yaitu dari segi ekologi dan ekonomi. Penelitian ini bertujuan menganalisis nilai Visual Evaluation of Soil Structure (VESS), sifat fisik tanah, serta hubungan keduanya pada hutan alam, agroforestri kompleks, dan agroforestri sederhana di Kabupaten Tapanuli Utara. Parameter yang diukur meliputi skor VESS, bobot isi, porositas, kadar air, dan kerapatan vegetasi dengan analisis uji pengaruh dan korelasi Pearson. Hasil menunjukkan nilai VESS berkisar Sq 1,16–2,40, dengan hutan alam terbaik (Sq 1,16), diikuti agroforestri kompleks (Sq 1,52), dan agroforestri sederhana (Sq 2,40). Sifat fisik tanah menunjukkan pola yang sama, yaitu hutan alam dan agroforestri kompleks memiliki bobot isi lebih rendah serta porositas dan kadar air lebih tinggi dibandingkan agroforestri sederhana. Nilai VESS berkorelasi sangat kuat dengan sifat fisik tanah, sehingga dapat digunakan sebagai metode yang cepat dan efektif dalam menilai sifat fisik tanah pada berbagai tipe tutupan lahan.

The conversion of forests into non-forest land, such as agriculture and plantations, can reduce soil physical quality. Agroforestry serves as an alternative land management system that provides both ecological and economic benefits. This study aimed to analyze Visual Evaluation of Soil Structure (VESS) scores, soil physical properties, and their relationships in natural forest, complex agroforestry, and simple agroforestry in North Tapanuli Regency. The parameters measured included VESS scores, bulk density, porosity, soil moisture content, and vegetation density, which were analyzed using analysis of variance and Pearson correlation. The results showed that VESS values ranged from Sq 1.16 to 2.40, with natural forest having the best condition (Sq 1.16), followed by complex agroforestry (Sq 1.52), and simple agroforestry (Sq 2.40). Soil physical properties showed a consistent pattern, where natural forest and complex agroforestry had lower bulk density and higher porosity and soil moisture compared to simple agroforestry. VESS values showed very strong correlations with soil physical properties, indicating that the VESS method can be used as a rapid and effective approach for assessing soil physical quality across different land cover types.