• Korean Journal of Organic Agriculture
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• v.16 no.1
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• pp.115-125
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• 2008

This study was conducted to determine adequate forage crop choice and optimal level of livestock manure, when different types and levels of the livestock manure were applied in corns or sorghum$\times$sorghum hybrids for the production of organic roughages by utilizing livestock manure. For the corn, yields of annual dry matter (DM) and total digestible nutrients (TDN) were highest in N+P+K-applied treatments, showing 17.3 and 11.7 ton/ha, respectively. Treatments applied 100% composted cattle manure (8.9 and 6.1 ton/ha) and 100% cattle slurry (9.4 and 7.5 ton/ ha) in contrast with chemical fertilizer-N had higher yields of DM and TDN than no fertilizer (4.8 and 2.7 ton/ha) and P+K-applied treatments (8.8 and 6.0 ton/ha). Particularly, treatments applied 150% composted cattle manure and 150% cattle slurry were markedly higher, which represented 11.4 and 7.6 ton/ha and 10.3 and 7.3 ton/ha, respectively. Crude protein (CP) contents for corns applied livestock manure ranged from 5.6 to 6.6%, which were significantly (p<0.05) higher than those of no fertilizer (3.9%) and P+K-applied treatments (5.5%). ADF (42.4%) and NDF (58.3%) contents for no fertilizer treatment were significantly (p<0.05) higher than those of other treatments. However, TDN contents were higher for livestock manure treatments than for no and/or chemical fertilizer treatments. In particular, TDN contents of treatments applied 150% composted cattle manure and 150% cattle slurry showed 72.3 and 70.8%, respectively and both treatments were significantly (p<0.05) higher than all of the other treatments. For the sorghum$\times$sorghum hybrid, yields of annual DM and TDN for 100% (12.4 and 7.4 ton/ha) and 150% (13.1 and 7.6 ton/ha) cattle slurry-applied treatments, and N+P+K-applied treatments (12.6 and 7.7 ton/ha) were significantly (p<0.05) higher than those of the others. In the others, 150% composted cattle manure (9.3 and 5.2 ton/ha) had higher annual DM and TDN yields than P+K-applied (8.4 and 4.8 ton/ha) and 100% composted cattle manure treatments (7.4 and 4.2 ton/ha), with no significant difference. Crude protein contents for sorghum$\times$sorghum hybrid applied P+K and cattle slurry were 8.8 and 8.6%, respectively. CP contents for both treatments were significantly higher than those of composted manure ($7.5{\sim}8.3%$) and no fertilizer (4.0%) treatments, but 100% livestock manure treatments had higher CP contents than 150%-applied treatments. ADF and NDF contents for N+P+K and cattle slurry-applied treatments were significantly (p<0.05) lower than the others. However, TDN contents were highest in N+P+K and cattle slurry-applied treatments, showing 61.2 and 58.3 to 59.4%, respectively. These results indicated that application of livestock manure instead of chemical fertilizer to the soil of forage crops might not only improve yields of DM and TDN, but also reduce environmental pollution by producing organic roughages through recycling of livestock manure.

• Korean Journal of Organic Agriculture
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• v.16 no.4
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• pp.421-434
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• 2008

This study was carried out to estimate the selection of appropriate forage crops, proper application levels of livestock manure, and carrying capacity per unit area for organic livestock, as influenced by livestock manure application levels compared with chemical fertilizer to corn and sorghum $\times$ sorghum hybrid, in order to produce organic forages by utilizing livestock manure. For both corns and sorghum $\times$ sorghum hybrids, no fertilizer plots had significantly (p<0.05) lower annual dry matter (DM), crude protein (CP) and total digestible nutrients (TDN) yields than those of other plots, whereas the N+P+K plots ranked the highest yields, followed by 150% cattle manure plots and 100% cattle manure plots. Dry matter, CP and TDN yields of cattle manure plots were significantly (p<0.05) higher than those of no fertilizer and P+K plots. In applying cattle manure, the yields of cattle slurry plots tended to be a little higher than those of composted cattle manure plots. Assuming that corns and sorghum $\times$ sorghum hybrids produced from this trial were fed at 70% level to 450kg of Hanwoo heifer with 400g of average daily gain, livestock carrying capacity (head/year/ha) ranked the highest in N+P+K plots of the case of corns (mean 6.7 heads), followed by 150% cattle slurry plots (mean 5.6 heads), 150% composted cattle manure plots (mean 4.8 heads), 100% cattle slurry plots (mean 4.4 heads), 100% composted cattle manure plots (mean 4.3 heads), P+K plots (mean 4.1 heads), and no fertilizer plots (mean 3.1 heads). Meanwhile, in case of sorghum $\times$ sorghum hybrids, N+P+K plots (mean 5.7 heads) ranked the highest carrying capacity, followed by $100{\sim}150%$ cattle slurry plots (mean $4.8{\sim}5.2$ heads), 150% composted cattle manure plots (mean 4.7 heads), 100 % composted cattle manure plots (mean 4.3 heads), P+K plots (mean 3.8 heads), and no fertilizer plots (mean 3.4 heads). The results indicated that replacing chemical fertilizer by livestock manure application to cultivation soil for forage crops could enhance not only DM and TDN yields, but also organic stock carrying capacity. In conclusion, it was conceived that organic forage production by reutilizing livestock manure might contribute to reduced environmental pollution and the production of environment friendly agricultural products through resources recycling.