Optimization of Productivity of Three Soybean Varieties Through Fertilization in Dry land Acid Soils in South Lampung

ABSTRACT The large area of dry land acidsoils in Lampung area are potentially developed to increase soybean production through phosphate fertilization. The objective was to determine optimal dosage of P fertilizers for growth and yield of soybeans in dry land acid soils. The experiment was conducted in October‐December 2016 in Natar Experimental Station, South Lampung District,using factorial randomized block design and replicated 3 times. The treatments consisted of threesoybean varieties: soybean varieties (V1 = Grobogan, V2 = Anjasmoro,V3 = Gepak Kuning), and P fertilization (P0 = no fertilizer P, P1 = 50 kg SP36/ha, P2 = 111 kg SP‐36/ha, P3 = 222 kg SP‐36/ha,P4 =333 kg SP‐36/ha, P5 = 132 kg Rock Phosphate/ha, P6 = 264 kg Rock Phosphate/ha, and P7 = 396 kg Rock Phosphate/ha). Agronomic variables observed were plant growth, plant height, number of leaves, number of root nodules per plant, root length, and yield of dry seeds per hectare. The result showed that interaction of varieties and dosage of P fertilizer affected significantly plant growth. The significant differences between varieties on number of leaves, number of root nodules, root length and yield of dry seeds, but no significantly different for plant growth. Yield of dried seed of varieties of Grobogan, Anjasmoro, Gepak Kuning reached 2.5; 1.4; and 2.0 t/ha, respesctively