Growth Performance of Sorghum in Coastal Land with Different Methods of Land Preparation and Plant Spacing

Abstract

Sorghum (Sorghum bicolor L.) is a cereal plant that has high adaptability on marginal coastal soils. Sorghum can be used as a source of food and feed, while high biomass production has the potential to be used as an industrial raw material for bioethanol production. The objective of this research was to study the combination of land preparation methods with spacing of sorghum in coastal land. The study was done at Muara Bangkahulu District, Bengkulu City. Initial observation found that the research field was sandy soil and dominated by Imperata cylindrica. The experiment was arranged in a split plot design and replicated 3 times. The main plots were land preparation methods that included no-tillage using glyphosate at 1.5 kg/ha for land clearing, using paraquat at 1.0 kg/ha for land clearing, and two times tillages or conventional tillage. Sub plots were variations of spacing that included 50 cm x 20 cm, 60 cm x 20 cm, and 75 cm x 20 cm. The results showed that there was no interaction between land preparation methods with variations of spacing on the growth of sorghum. However, the method of land preparation significantly affected only the leaf area, where the treatment of no-tillage using glyphosate and paraquat increased leaf areas and was significantly different from conventional tillage. Variation of spacing also affected leaf areas and panicle length where the broadest leaf was 9,064.56 cm 2 and the longest panicle was 20.37 cm observed at 70 cm x 20 cm spacing. Thus, no-tillage using glyphosate or paraquat for land clearing are recommended for growing sorghum in coastal lands.