Sorghum cultivation of the ratoon system for increased yields in dry land

Abstract

Planting sorghum twice a year on dry land is constrained by the short duration of rainfall, so it requires technology to increase yields with the ratoon cropping system. The research was carried out in Agricultural Technology Research and Assessment Installation of Bajeng, Gowa, South Sulawesi from March to October 2019. The superior genotypes of sorghum were planted on marginal land as the main crop with a spacing of 75 cm x 20 cm (66,666 plants/ha). The ratoon plant used a split-split plot design. The main plot consisted of two mulches: M1=no mulch + 50% dose of main crop fertilization and M2=sorghum stover mulch + biodecomposer 1kg/ha without NPK fertilizer. The sub-plots consisted of 2 populations: P1=population of 66,666 plants/ha (1 shoot/hole), P2=133,332 ratoon plants/ha (2 shoots per hole). The sub-sub-plots consisted of 5 (five) genotypes/varieties of sorghum: V1=Numbu, V2=No.58-1, V3=No. 86.1, V4=No.103-1 and V5=No. 113-1, so that 20 treatment combinations were obtained with 3 replications. The results showed that to obtain high grain yield in ratoon cultivation in dry land, NPK fertilization (150-100-50)/ha is still necessary. The increase in population density of ratoon from 66,666 to 133,333 plants/ha significantly affected the increase in grain yield. Sorghum genotype No. 58-1, No. 86-1, No. 103-1 and No. 113-1 is technically and economically feasible to be developed in the cultivation of the double harvest ratoon system with the profit (Rp 10,989,000-12,247,500/ha) from the cultivation of sorghum once the main crop (Rp 4,003,000-4,856,000). The R/C value is 2.00-2.10 and the MBCR value is 2.27-2.38.