Pengaruh Variasi Pemupukan NPK terhadap Parameter Fisika-Kimia Perairan serta Kadar Protein dan Lemak Ulva lactuca dalam Sistem Budidaya

Abstract

Produksi rumput laut yang masih bergantung pada kondisi alam dan cuaca cenderung fluktuatif dan belum memberikan hasil maksimal. Budidaya disertai dengan sistem pemupukan menjadi salah satu pendekatan yang dapat meningkatkan produktivitas. Namun, dosis pupuk yang efektif untuk memperoleh hasil optimal masih belum diketahui. Penelitian ini bertujuan menganalisis pengaruh pemberian variasi dosis pupuk NPK terhadap parameter fisika-kimia perairan, kadar protein, dan kadar lemak U. lactuca dalam sistem budidaya. Metode budidaya yang digunakan metode tali (long-line method) dengan masa perawatan 60 hari. U. lactuca diberi lima perlakuan dengan tiga ulangan pada setiap perlakuan. Rancangan perlakuan terdiri atas kontrol, 0 ppm, 10 ppm, 20 ppm, dan 30 ppm pupuk NPK, dengan masing-masing perlakuan dilakukan dalam 10 liter air laut. Perlakuan kontrol merupakan air laut yang tidak diberi rumput laut, perlakuan 0, 10, 20, dan 30 ppm secara berturut-turut merupakan air laut diberi pupuk NPK dengan dosis 0; 0,1; 0,2; dan 0,3 gram. Pemberian pupuk NPK dengan dosis tersebut dilakukan setiap 7 hari sekali. Analisis kadar protein dan kadar lemak U. lactuca dilakukan dengan metode proksimat. Penelitian menunjukkan dosis pupuk optimal berdasarkan pertumbuhan mutlak dan parameter fisika-kimia perairan didapatkan pada perlakuan 10 ppm serta berdasarkan kadar protein dan lemak didapatkan pada perlakuan 20 ppm.

Seaweed production, which still depends on natural conditions and weather, tends to be fluctuating and has not yet yielded maximum results. Cultivation accompanied by a fertilization system is one approach that can increase productivity. However, the effective fertilizer dosage to obtain optimal results is still unknown. This study aims to analyze the effect of varying NPK fertilizer doses on water physicochemical parameters, protein content, and fat content of U. lactuca in a cultivation system. The cultivation method used is the long-line method with a cultivation period of 60 days. U. lactuca was subjected to five treatments with three replicates per treatment. The treatment design consisted of a control, 0 ppm, 10 ppm, 20 ppm, and 30 ppm NPK fertilizer, with each treatment conducted in 10 liters of seawater. The control treatment consisted of seawater without seaweed, while the 0, 10, 20, and 30 ppm treatments consisted of seawater with NPK fertilizer doses of 0, 0.1, 0.2, and 0.3 grams, respectively. The NPK fertilizer was applied at these doses every 7 days. Protein and fat content analysis of U. lactuca was performed using the proximate method. The study showed that the optimal fertilizer dose based on absolute growth and water physicochemical parameters was obtained at the 10 ppm treatment, while based on protein and fat content, it was obtained at the 20 ppm treatment.