Forage Production and Nutritional Quality of Sorghum bicolor cv. Samurai-1 in Response to Urea and Arbuscular Mycorrhizal Fungi on Post-Coal Mining Land in South Kalimantan

¹ Nutrition and Feed Science Study Program, Graduate School of IPB University, IPB Dramaga Campus, Bogor-West Java, 16680, Indonesia
² Animal Feed Technology Study Program, Politeknik Negeri Tanah Laut, Tanah Laut Regency-South Kalimantan, 70815, Indonesia
³ Department of Nutrition and Feed Technology, Faculty of Animal Science, IPB University, IPB Dramaga Campus, Bogor-West Java, 16680, Indonesia
⁴ National Research and Innovation Agency (Badan Riset dan Inovasi Nasional/BRIN) of Indonesia, KST Cibinong, Bogor-West Java, Indonesia
⁵ Department of Animal Husbandry, Faculty of Agriculture, Universitas Islam Kalimantan Muhammad Arsyad Al Banjari Banjarmasin. Banjarmasin-South Kalimantan, Indonesia
⁶ PT Arutmin Indonesia, Asamasam Mine, Tanah Laut Regency-South Kalimantan, Indonesia

^* Corresponding author: kuswoyo@politala.ac.id
^† Corresponding author: labdull@apps.ipb.ac.id

Abstract

Forage is a critical component in ruminant nutrition, yet the availability of land for cultivating quality forage is increasingly limited. Post-coal mining lands offer a promising alternative for forage production, despite their poor soil fertility and degraded structure. This study aimed to evaluate the forage production and nutritional quality of Sorghum bicolor cv. Samurai-1 in response to different urea fertilization rates and the application of arbuscular mycorrhizal fungi (AMF) on post-coal mining land in South Kalimantan, Indonesia. A Completely Randomized Design (CRD) with a two-factorial arrangement and four replications was employed. Factor A consisted of urea rates (200, 300, and 400 kg/ha), while Factor B involved AMF application (with and without). Results indicated that both urea and AMF treatments had a highly significant effect (p < 0.001) on sorghum agronomic traits, including plant height, stem diameter, leaf length, leaf width, and number of leaves. Biomass yield (both fresh and dry matter) was significantly enhanced, while the combined application of urea and AMF also improved crude protein, crude fat, and crude fiber contents. These findings suggest that integrating urea fertilization with AMF inoculation can substantially enhance the productivity and forage quality of sorghum cultivated on degraded post-mining land.