The Effect of Planting Distance and Fertilization on the Land Equivalence Ratio of Intercropping Indigofera zollingeriana and Brachiaria decumbens Based on Dry Matter Production

Pengaruh Jarak Tanam dan Pemupukan terhadap Nisbah Kesetaraan Lahan Tumpangsari Indigofera zollingeriana dan Brachiaria decumbens Berdasarkan Produksi Bahan Kering

Abstract

The productivity and quality of forage in Indonesia remain relatively low, particularly during the dry season. This study aimed to analyze the effects of planting spacing and fertilization on the Land Equivalent Ratio (LER) of an intercropping system involving the legume Indigofera zollingeriana and the grass Brachiaria decumbens, based on dry matter production. The experiment employed a Completely Randomized Design (CRD) with a factorial pattern, comprising Factor A (planting patterns and spacing K1–K8) and Factor B (manure fertilization at 10 tons/ha versus no fertilization), with three replications. Observed variables included leaf and stem dry matter production for each plant species and the LER value. The results showed that the K3P planting spacing combination (I. zollingeriana 1.00 m × 1.50 m and B. decumbens 0.25 m × 0.25 m) combined with fertilization yielded the most optimal growth. This combination recorded an LER value of 2.39 (LER > 1), indicating that this intercropping system was 139% more efficient in land use compared to monoculture systems. The integration of this legume and grass proved effective in enhancing productivity as well as the efficiency of nutrient, water, and sunlight utilization.

Keywords: Brachiaria decumbens, land equivalent ratio, Indigofera zollingeriana