Growth, Productivity and Land Equivalent Ratio of Soybean-Corn Intercropping on the Different Potassium and Husk Ash Dose under Saturated Soil Culture on Tidal Swamp

Abstract

Saturated soil culture (SSC) is a cultivation technology that gives continuous irrigation and maintains water depth constantly and makes soil layer in saturated condition. This technology is appropriate to prevent pyrite oxidation on tidal swamp and has been proved to increase the  soybean productivity  on  tidal swamp.Intercropping soybean-corn on the saturated soil culture technology will increase input efficiency  and farmer income in the cultivation system. The experiment was conducted at Mulyasari Village, Tanjung Lago Sub District, Banyuasin District, South Sumatera Province (11 feet above sea level,  2°38'42.35" South Latitude, and 104°45'5.92" East Longitude),  from  May to September.

The experiment used a randomize complete block design with 2 factors,  three replications. The first factor is potassium dose, consisted of :  0, 30, 60, and 90 kg K₂O ha^-1. The second factor is husk ash, consisted of : without husk ash , and 1 ton ha^-1 husk ash. The calculation of land equivalent ratio (LER) was made with comparing  intercropping  to the monoculture of  soybean and corn with treatment potassium  :  0 , 30 , 60, and 90  kg K₂O ha^-1, on without husk ash and plus husk ash .The result showed that the higher productivity of soybean and corn  were obtained on 90 kg K₂O ha^-1 with application husk ash. In this fertilizer combination on the intercropping, the productivity of corn and soybean were 7.41 ton ha^-1and 1.93 ton ha^-1, but on the monoculture the productivity of corn and soybean were 8.77 ton ha^-1 and 3.54 ton ha^-1. The land equivalent ratio of intercropping was obtained > 1, with range 1.37-1.49. This means that intercropping system increased land efficiency