Evaluasi Status Nitrogen Tanah Pada Berbagai Kondisi Topografi Di Perkebunan Kelapa Sawit (Elaeis Guineensis Jacq) Desa Juma Tombak Kecamatan Sinembah Tanjung Muda Hilir Kabupaten Deli Serdang

Abstract

Nitrogen merupakan unsur hara esensial yang berperan penting dalam pertumbuhan dan produktivitas tanaman kelapa sawit. Kandungan nitrogen tanah dipengaruhi oleh berbagai faktor lingkungan, salah satunya kondisi topografi yang berhubungan dengan proses erosi, pencucian, dan distribusi bahan organik tanah. Penelitian ini bertujuan untuk mengevaluasi status nitrogen tanah pada berbagai kondisi topografi di perkebunan kelapa sawit rakyat Desa Juma Tombak, Kecamatan Sinembah Tanjung Muda Hilir, Kabupaten Deli Serdang. Penelitian dilaksanakan pada tiga kelas topografi, yaitu datar (0–8%), landai (8–15%), dan agak curam (15–25%), dengan pengambilan sampel tanah pada dua kedalaman, yaitu 0–40 cm dan 40–80 cm. Analisis nitrogen total dilakukan menggunakan metode Kjeldahl, sedangkan pH tanah dianalisis secara potensiometri dan C-organik menggunakan metode spektrofotometri UV–VIS. Data dianalisis secara deskriptif kuantitatif dan diuji secara statistik menggunakan Analysis of Variance (ANOVA). Hasil penelitian menunjukkan bahwa kandungan nitrogen total tanah pada seluruh kondisi topografi umumnya tergolong rendah hingga sedang, dengan nilai yang lebih tinggi pada lapisan tanah 0–40 cm dibandingkan lapisan 40–80 cm. Hasil uji ANOVA menunjukkan bahwa faktor kedalaman tanah berpengaruh nyata terhadap kandungan nitrogen tanah, sedangkan kondisi topografi dan interaksinya dengan kedalaman tanah tidak berpengaruh nyata. Hal ini menunjukkan bahwa distribusi nitrogen tanah di lokasi penelitian lebih dipengaruhi oleh perbedaan lapisan tanah daripada variasi topografi. Hasil penelitian ini diharapkan dapat menjadi dasar dalam perencanaan pengelolaan tanah dan strategi pemupukan nitrogen yang lebih efektif pada perkebunan kelapa sawit dengan kondisi topografi beragam. Nitrogen is an essential nutrient that plays a crucial role in the growth and productivity of oil palm plantations. Soil nitrogen availability is influenced by various environmental factors, including topographic conditions, which are closely related to erosion, leaching, and the distribution of soil organic matter. This study aimed to evaluate soil nitrogen status under different topographic conditions in a smallholder oil palm plantation located in Juma Tombak Village, Sinembah Tanjung Muda Hilir District, Deli Serdang Regency, North Sumatra. The research was conducted on three topographic classes, namely flat (0–8%), gently sloping (8– 15%), and moderately steep (15–25%) areas. Soil samples were collected at two depths, 0–40 cm and 40–80 cm. Total nitrogen content was analyzed using the Kjeldahl method, soil pH was measured by the potentiometric method, and soil organic carbon was determined using UV–VIS spectrophotometry. The data were analyzed descriptively and statistically using Analysis of Variance (ANOVA). The results showed that total soil nitrogen content across all topographic conditions generally ranged from low to moderate, with higher values observed in the 0–40 cm soil layer compared to the 40–80 cm layer. ANOVA results indicated that soil depth had a significant effect on soil nitrogen content, whereas topographic conditions and their interaction with soil depth had no significant effect. These findings suggest that soil nitrogen distribution in the study area is more strongly influenced by soil depth than by variations in topography. This study provides scientific information that can support soil management planning and the development of more effective nitrogen fertilization strategies in oil palm plantations with varying topographic conditions.