Study On Forage Cropping System Adapted to Soil Characteristics in Reclaimed Tidal Land.

This study was conducted to find out the optimum cropping system for the stable production of forage crops in the newly reclaimed land located at Gwanghwal and Gyehwa region of Saemangum reclaimed land from October, 2009 to October, 2011. Whole-crop-barley(WCB, Yeongyang), Rye(Gogwoo) and Italyan rye grass(IRG, passerel plus) as winter forage crops and Corn(Gwangpyeongok) and sorghum×sudangrass hybrid(SSH,G7) as a summer crops were cultivated. Soil chemical properties, forage quality, growth and yield were examined. The testing soil showed saline strong alkali soil where the contents of organic matter, available phosphate and exchangeable calcium were very low, while exchangeable sodium and magnesium were higher. Changes of soil salinity during the growing season of forage crops were less than 0.1%, and the growth of forage crops was not affected by salt injury. Standing rates of winter crops were higher in the order of Rye, WCB, and IRG, while the dry matter yield of winter crops was higher in the order of Rye, IRG and WCB. The highest crude protein (CP) content was recorded in IRG, and total digestive nutrients (TDN) contents were increased in the order of WCB, IRG, and Rye. The total digestive nutrients(TDN) content was higher in corn, whereas other feed value was higher in SSH. After experiment, the pH value was lowered, and the contents of available phosphate, exchangeable calcium and potassium were increased. But the contents of organic matter and exchangeable magnesium, sodium were decreased. After continually cultivating winter and summer crops in cropping system, fresh matter yield increased, compared to WCB-Corn(74,740kg/ha), IRG- SSH 10%, IRG-Corn 7%, Rye-SSH 6%, Rye-Corn and WCB-SSH 3%. Dry matter yield increased, compared to WCB-Corn(20,280kg/ha), IRG- SSH 7%, Rye-SSH 6%, IRG-Corn/WCB-SSH/Rye-Corn 3%. The TDN yield increased, compared to WCB-Corn(13,830kg/ha), IRG-SSH 2%, WCB-SSH and IRG-Corn 1%. Therefore, we suggest that the crop combination of IRG-SSH and WCB- SSH would be preferred for silage stable production.

Key words: Forage crops, Cropping system, Soil characteristics, Reclaimed tidal land