Screen of Green Manure Crops for Cultivation on Agricultural Land with Spring Season in the Central Regions of Korea

The green manure crops are returned to soil when the plants are still green. The green manure crops play a role in reducing chemical fertilizers, improvement of soil fertility, reduction of soil erosion, weed control, and landscapes effect. Typical green manure crops are barley green manure, hairy vetch, chines milk vetch and clovers. We sowed 49 species of green manure crops in upland soil to increase the usage of green manure crops. We searched the effectiveness of green manure yield, C/N ratio, soil mulching, and landscape effect. The green manure crops that have $5tonha^{-1}$ or more of green manure yield (fresh weight) were 6 gramineous crops, 4 leguminous crops, and 3 others. Green manures yield in a short growth period was higher in gramineous crops than leguminous crops. Among the green manure crops, 3 gramineous crops, 12 leguminous crops, and 3 others were under 25 in C/N ratio. Seven gramineous crops, 8 leguminous crops, and 5 others were over 50% of soil covering rate. Green manure crops that have beautiful flowers were in total 16 kinds, such as 4 gramineous crops, 6 leguminous crops, and 6 others. In result, based on green manure yield and C/N ratio, excellent species in the green manure crops were 4 species (triticale, 2 kinds of hairy vetch, and lupin). Green manure crops that were effective at soil mulching were 20 species, like hairy vetch, oats, sorghum, phacelia, buckwheat, etc. Buckwheat, crotalaria, mustard plant, phacelia, and etc. could be available for landscape crops.