Karakteristik Fisik Tanah pada Berbagai Tipe Penggunaan Lahan di Kawasan Kampus IPB Dramaga

Abstract

Perbedaan tipe penggunaan lahan dan praktik pengolahan tanah di kawasan Kampus IPB Dramaga memengaruhi karakteristik fisik tanah. Penelitian ini bertujuan membandingkan karakteristik fisik tanah dan kandungan C-organik pada tujuh tipe penggunaan lahan serta menganalisis hubungan kemantapan agregat tanah dengan sifat fisik tanah lainnya dan C-organik. Contoh tanah agregat utuh diambil pada kedalaman 0–20 cm dan 20–40 cm menggunakan metode purposive sampling. Hasil analisis ragam (ANOVA) pada taraf nyata 5% menunjukkan bahwa jenis penggunaan lahan berpengaruh sangat nyata terhadap karakteristik fisik tanah, indeks stabilitas agregat, dan kandungan C-organik. Taman Hutan Kampus memiliki bobot isi terendah (0,88 g/cm³), ruang pori total tertinggi (59,57%), dan indeks stabilitas agregat tertinggi (136,39; sangat stabil). Sebaliknya, pertanian konvensional memiliki bobot isi lebih tinggi dan karbon organik lebih rendah akibat pengolahan tanah intensif. Hasil analisis menunjukkan bahwa pada kedalaman 0–20 cm, C-organik memiliki nilai koefisien determinasi (R² = 0,5) tertinggi dibandingkan parameter lainnya, yang menunjukkan bahwa sekitar 50% variasi nilai indeks stabilitas agregat dapat dijelaskan oleh variasi kandungan C-organik. Pada kedalaman 20–40 cm, seluruh parameter memiliki nilai koefisien determinasi yang rendah. Pengelolaan lahan yang mempertahankan tutupan vegetasi dan meminimalkan gangguan mekanis diperlukan untuk menjaga karakteristik fisik tanah yang baik, ditandai dengan bobot isi yang lebih rendah serta ruang pori total dan kemantapan agregat yang lebih tinggi.

Differences in land-use types and soil management practices within the IPB Dramaga Campus area affect soil physical characteristics. This study aims to compare soil physical characteristics and organic C content across seven land-use types and to analyze the relationship between soil aggregate stability and other soil physical properties and organic C. Samples of undisturbed soil aggregates were collected at depths of 0–20 cm and 20–40 cm using the purposive sampling method. The results of an analysis of variance (ANOVA) at the 5% significance level indicate that land-use type has a highly significant effect on soil physical characteristics, aggregate stability index, and organic C content. The Campus Forest Park had the lowest bulk density (0.88 g/cm³), the highest total pore space (59.57%), and the highest aggregate stability index (136.39; very stable). In contrast, conventional agriculture had a higher bulk density and lower organic C content due to intensive tillage. The results of the analysis show that at depths of 0–20 cm, organic C has the highest coefficient of determination (R² = 0.5) compared to other parameters, indicating that approximately 50% of the variation in aggregate stability index values can be explained by variations in organic carbon content. At a depth of 20–40 cm, all parameters had low coefficient of determination values. Land management practices that maintain vegetation cover and minimize mechanical disturbance are necessary to preserve good soil physical characteristics, as indicated by lower bulk density and higher total pore space and aggregate stability.