Pengaruh Metode Aplikasi Pupuk terhadap Sebaran Akar dan Kandungan Hara pada Kelapa Sawit

Abstract

Kelapa sawit merupakan komoditas perkebunan yang produktivitasnya sangat bergantung pada ketepatan cara pemberian pupuk. Metode pemupukan u-shape diterapkan dengan menabur pupuk membentuk setengah lingkaran pada tiga sisi di sekeliling tanaman agar terjangkau oleh perakaran aktif. Kajian dilaksanakan di Sukamandang Estate, PT Minamas Plantation, Kalimantan Tengah, pada lima pohon berusia sepuluh tahun (n=5), dengan mengukur bobot kering akar dan kadar hara N, P, K, Ca, Mg, serta S pada zona aplikasi pupuk dan tanpa aplikasi pupuk, pada jarak 1 m, 2 m, dan 2,5 m dari pangkal batang. Bobot akar lebih tinggi pada zona tabur dan terus meningkat seiring bertambahnya jarak dari pangkal batang. Kadar N, K, dan Ca lebih unggul di zona u-shape, didukung bobot akar yang juga lebih besar. Mg dan S tetap terserap lebih banyak meski kadarnya lebih rendah, karena massa akar yang lebih tinggi. Kadar P relatif setara di seluruh titik, namun serapannya tetap berbeda mengikuti bobot akar. Metode pemupukan u-shape dinilai telah sesuai prinsip efisiensi pemupukan.

Oil palm is a plantation crop whose productivity is highly dependent on the accuracy of fertilizer application methods. The u-shape fertilization method was applied by spreading fertilizer in a semicircle on three sides around the plant so that it could be reached by the active root system. The study was conducted at Sukamandang Estate, PT Minamas Plantation, Central Kalimantan, on five ten year old trees (n=5), by measuring dry root weight and nutrient levels of N, P, K, Ca, Mg, and S in both fertilized and unfertilized zones at distances of 1 m, 2 m, and 2.5 m from the base of the trunk. Root weight was higher in the fertilized zones and continued to increase with greater distance from the base of the trunk. Concentrations of N, K, and Ca were higher in the u-shape zones, supported by greater root weight. Although Mg and S concentrations were lower, their uptake remained higher due to the greater root mass. P levels were relatively similar across all points, but uptake varied according to root weight. The u-shape fertilization method was found to align with the principles of fertilization efficiency.