Effectiveness of Sludge Organic Fertilizer and its Combination with Inorganic Fertilizer on Growth, Nutrient Uptake, and Yield of Mustard (Brassica rapa L.)

Liquid waste from the dairy industry becomes an environmental problem if it is not processed properly, so several technologies have been created from this waste, one of them is sludge organic fertilizer. The aim of this research is to determine the combination of organic and inorganic fertilizers to support the growth, nutrient uptake and yield of mustard. The factors of this research include S0 = NPK 100% (300 kg.ha-1), S1 = 25% sludge organic fertilizer + 75% NPK (6.25 ton.ha-1+ 225 kg.ha-1), S2 = 50% sludge organic fertilizer + 50% NPK (12.5 ton.ha-1+ 150 kg.ha-1), S3 = 75% sludge organic fertilizer + 25% NPK (18.75 ton.ha-1 + 75 kg.ha-1) and S4 = sludge organic fertilizer 100% (25 ton.ha-1). The research result shows that the combination treatment of sludge organic fertilizer with NPK inorganic fertilizer can increase the uptake of nitrogen, phosphorus, and potassium nutrients and enhance mustard growth and yield. Treatment of sludge organic fertilizer 25% + NPK 75% being the best in nutrient uptake, growth, and yield of mustard. Meanwhile 75% sludge organic fertilizer + 25% NPK treatment produces better soil chemical properties. This research reveals that mustard still need organic and inorganic fertilizers.