Evaluasi Status Nitrogen Tanah Sawah Irigasi Terhadap Produktivitas Padi Di Desa Raja Maligas Kecamatan Huta Bayu Raja Kabupaten Simalungun Provinsi Sumatera Utara

Abstract

Tanah sawah irigasi merupakan lahan utama dalam produksi padi, namun produktivitasnya sangat dipengaruhi oleh status unsur hara tanah, terutama nitrogen. Nitrogen berperan penting dalam pertumbuhan vegetatif dan pembentukan hasil tanaman padi, namun ketersediaannya di dalam tanah sawah sering mengalami penurunan akibat proses kehilangan hara. Penelitian ini bertujuan untuk mengevaluasi status nitrogen irigasi serta hubungannya dengan produktivitas padi di Desa Raja Maligas, Kecamatan Huta Bayu Raja, Kabupaten Simalungun, Provinsi Sumatera Utara. Penelitian dilaksanakan pada Oktober– Desember 2025 menggunakan metode survei dengan pengambilan sampel tanah secara purposive random sampling pada 10 titik pengamatan yang mewakili luas lahan sawah irigasi 500 ha. Analisis laboratorium dilakukan untuk menentukan nitrogen total, C-organik, dan pH tanah sedangkan data produktivitas padi diperoleh melalui wawancara petani. Hasil penelitian menunjukkan bahwa pH tanah berada pada kisaran 4,9–5,3 dengan kriteria masam hingga sangat masam, kandungan C-organik tergolong sangat rendah hingga rendah (0,55–1,19%), dan status nitrogen total tanah sangat rendah hingga rendah (0,05-0,13). Analisis korelasi menunjukkan adanya hubungan positif dengan tingkat sedang antara pH tanah dan nitrogen total serta hubungan positif antara C-organik dan nitrogen total. Disimpulkan bahwa kondisi pH tanah dan rendahnya C-organik mempengaruhi ketersediaan nitrogen pada lahan sawah irigasi, sehingga diperlukan perbaikan pH tanah dan peningkatan bahan organik untuk mendukung peningkatan produktivitas padi secara berkelanjutan. Paddy soils are the main land resources for rice production; however, their productivity is strongly influenced by soil nutrient status, especially nitrogen. Nitrogen plays a crucial role in vegetative growth and yield formation of rice plants, yet its availability in paddy soils often decreases due to nutrient loss processes. This study aimed to evaluate the status of nitrogen, of irrigated rice fields and their relationships with rice productivity in Raja Maligas Village, Huta Bayu Raja Subdistrict, Simalungun Regency, North Sumatra Province. The research was conducted from October to December 2025 using a survey method with purposive random sampling at 10 observation points representing 500 ha of irrigated paddy soils. Laboratory analyses were carried out to determine total nitrogen, organic carbon, and soil pH, while rice productivity data were obtained through farmer interviews. The results showed that soil pH ranged from 4.9 to 5.3, classified as acidic to strongly acidic. Organic carbon content was categorized as very low to low (0.55–1.19%), and very low to low soil total nitrogen status (0.05-0.13). Correlation analysis indicated a moderate positive relationship between soil pH and total nitrogen, as well as a positive relationship between organic carbon and total nitrogen. It can be concluded that soil pH conditions and low organic carbon content affect nitrogen availability in irrigated rice fields; therefore, soil pH and the enhancement of organic matter are necessary to support sustainable increases in rice productivity.