• Korean Journal of Soil Science and Fertilizer
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• v.36 no.5
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• pp.333-343
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• 2003

This experiment was carried out to improve the utilization of liquid pig manure (LPM) for rice at the two textures of valley soil in 2000 and 2001. The soil textures were coarse loamy and fine loamy in Sachon and Jisan series, respectively. Treatments consisted of no fertilized plot, chemical fertilized plot, LPM 150%, LPM 100%, LPM 100%+NK (top dressing) 30%, LPM 70%+NK 30%, LPM 50%+NK 50% plot. LPM was applied as basal fertilizer compare to nitrogen of chemical fertilized plot. Total N contents in the LPM were 6.0 and $4.5g\;kg^{-1}$ in 2000 and 2001, respectively. After the experiment, P and K contents of soils were not difference between chemical and LPM application plots. But heavy metal contents in soils were slightly higher in LPM application plots than in chemical fertilized plot. Immediately after LPM application, ammonia gas content was $18mg\;kg^{-1}$ in LPM 150% plot, but it was $3mg\;kg^{-1}$ in LPM 50% plot. Two days after LPM application, ammonia gas content was 3 times higher in coarse loamy than in fine loamy soil. After rotary tillage, ammonia gas was not detected at all LPM treatments. This result suggests that rotary tillage can reduce the nasty smell of LPM quickly. Inorganic nitrogen, $NO_3$ and $NH_4$, contents in water of paddy was higher at coarse loamy soil from rice transplanting to tillering stage. After that season, inorganic nitrogen contents of water were not different according to soil texture and treatments. Content of $NH_4-N$ in soil solution was higher at LPM plots than chemical fertilizer plot. Total nitrogen contents in rice plant after harvesting were higher at chemical fertilization plot than LPM application plot, but K contents showed an opposite tendency. Rice yield was decreased only in LPM plots at two soil textures. But yield was not significantly difference between chemical fertilizer and LPM+top dressing plots at coarse loamy soil and increased 5% at LPM 50%+NK 50% plot at fine loamy soil in 2001.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.34-40
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• 2011

Cover crop can be used to suppress weeds by competition for light and nutrient. Objective of this study was to evaluate the effectiveness of legume cover crops on change of weed community in no-till corn cultivation. Two legume cover crops, hairy vetch and crimson clover were grown in the field, and succeeding corn was sown on 4 May, 2010. The distribution of weed was surveyed at 15 April, 1 June, and 20 August. At 15 April, the weed biomass in hairy vetch field was higher than in crimson clover field. The dominant weeds were Capsella bursa-pastoris L. and Stellaria aquatica L. in hairy vetch and crimson clover fields, respectively. At vegetative stage of corn, occurred weeds in hairy vetch and crimson clover fields were four and six species, respectively, while the weed was occurred with nine species in conventional. Also the dry weight of weed was decreased by 82 and 75% in hairy vetch and crimson clover fields compared to conventional. On the other hand, after harvest of corn, occurred weed in hairy vetch, crimson clover and conventional was five, four and five species, respectively. Dry weight percentage of occurred weed in conventional was 23.5%, and the value was higher than 13.8 and 14.7% in hairy vetch and crimson clover fields, respectively. Stellaria aquatica L. as winter annual weed only occurred in cover crop field during corn growing season. It is these possibilities that low soil temperature and light interception by soil cover of legume cover crop.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.4
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• pp.216-222
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• 2002

Field experiments were conducted to investigate the effect of various cultural practices on methane($CH_4$) emission in tillage and no-tillage practice in a clayey paddy soil from 1998 to 2000. The factors evaluated in tillage and no-tillage methods were types of nitrogen fertilizers, application method of chemical fertilizers, rice straw application and cultivation method. Of the nitrogen fertilizers, the amount of $CH_4$ emission in ammonium sulfate plot was the lowest, regardless of tillage and the application method. 26.4~41.1% of reduction by ammonium sulfate compared with urea. But in no-tillage which have problem of poor rice yield than tillage, coated urea was more effective nitrogen fertilizer because that showed similar $CH_4$ emission and highest rice yield at 80% of dosage of nitrogen. No-tillage plot emitted lower $CH_4$ than tillage plot where the fertilizers were incorporated. On the contrary, no-tillage plot showed a little higher $CH_4$ emission compared with tillage plot for the surface application. When rice straw was applied, no-tillage practice reduced methane emission by 26.6% compared with tillage practice, but showing a little difference of 10.7% in no application. With cultivation method, no-tillage practice reduced methane emission 26.6% compared with tillage for the 30-d-old seedling transplanting. But for the dry direct seeding practice, no-tillage was a less effective because considerable amounts of rice straw incorporated by tillage were more decomposed aerobically in the soil and emitted as $CO_2$ to the atmosphere with flooding in no-tillage soil.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.1
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• pp.72-77
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• 1989

A study was conducted to obtain acid tolerant and superior Rhizobium meliloti strain for alfalfa on hilly acid soils. With host plant, eight isolates of R, meliloti selected in the vicinity of Milyang were evaluated for their ability to establish symbiotic effectiveness in acidified tube culture medium and vermiculite pot with different urea levels. Among isolates "YA03" was characterized for the ability to manifest to acid tolerance in three different soils of which pH were 5.0, 6.0, and 7.5. The results obtained were summarized as follows: 1. Of eight isolates "YA03" and "YA09" performed nodule in the tube medium of pH5.0, and in the symbiotic effectiveness YA03 was superior to others. 2. Alfalfa growth and $N_2-fixing$ activity by the inoculation of "YA03" isolate were better than others at the level of urea 1.25mM as well as nonurea. 3. Application of urea with inoculation of "YA03" islate to alfalfa was one of the effective factors for symbiotic effectiveness. 4. In infertile soil of pH5.0 inoculation of R. meliloti "YA03" to alfalfa caused the increase of shoot dry matter of 320% as compared to the control, and the total amount of yield was 131% as much yield in moderate fertile soil of pH7.5. Finally R. meliloti "YA03" isolate was selected as an acid tolerant strain.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.847-852
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• 2011

Green manure crops are mainly used to reduce the application of chemical fertilizers. Mixture of green manure crops have beneficial effects in agroecosystem. In this study, experiments were conducted to evaluate the effects of monoculture and mixtures of crimson clover (Trifolium incarnatum) on rice growth and yield in paddy. This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts) from Oct. 2007 to Oct. 2009 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Seeding rates of crimson clover (CC) were consisted of monoculture (CC2, 3, 4 kg and hairy vetch 5 kg $10a^{-1}$) and mixtures (CC 2 + barley 7, CC 3 + barley 7, CC 4 + barley 7, and CC2 + hairy vetch $5kg\;10a^{-1}$). Seeds were drilled by partial tillage machine on 9th Oct. in 2007. Monoculture and mixture of crimson clover as a green manure crop was incorporated in soil for rice cultivation on 15th May in 2008. Chemical fertilizers had not been applied to monoculture and mixture plots. The biomass and N production of monoculture plots were lower than mixture plots. The biomass and N production of CC 2 + hairy vetch $5kg\;10a^{-1}$ plot were the highest among mixtures treatments. In rice growing season, ammonium nitrogen concentrations in soil were a little high trends at CC 2 + hairy vetch $5kg\;10a^{-1}$ plot. And soil bulk density and porosity were improved at mixture plot after rice harvesting. The rice yield of CC 2 + hairy vetch $5kg\;10a^{-1}$ plot was not significantly different from conventional practice plot. These results indicated that cropping of crimson clover with hairy vetch mixture was better than barley mixture for environmental friendly rice cultivation.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.853-858
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• 2011

The cultivation methods are important for determining crop yield of green manure. The effect of cultivation methods of green manure crops (GMC) on biomass and rice yield was investigated. This experiment was conducted at Sinheung series (fine loamy, mixed, nonacid, mesic family of Fluvaquentic Endoaquepts from Oct. 2007 to Oct. 2008 at the National Institute of Crop Science (NICS), RDA, Suwon, Gyeonggi province, Korea. Seven GMC (hairy vetch, barley, Chinese milk vetch, rye, crimson clover, oats, rattail fescue) were cultivated and incorporated on paddy soil by broadcasting before rice harvesting (BBRH) and partial tillage seeding (PTS). Among the three leguminous GMC, the biomass and N production were the highest at the hairy vetch of PTS. Among the four gramineae GMC, the biomass and N production tended to be higher in the rye of BBRH and barley of PTS. The C/N ratio (56.5~74.2) of rye was high compared with hairy vetch (14.1). Among the GMC, the incorporation of hairy vetch increased $NH_4$-N contents in rice paddy soil at 14 and 42 days after transplanting. These results showed that hairy vetch had no significant to rice yield compared with conventional fertilization. Therefore, hairy vetch seems to be the most efficient green manure crop as an alternatives to chemical N fertilizer in the central regions of Korea.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.709-716
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• 2011

In order to collect basic data of soil environment in the Vicinity of King Sejong Station, King George Island, Antarctica, the physico-chemical characteristics of soils were investigated. Soil samples were collected in Barton Peninsula from 13 sites according to direction from the Sejong Cape. Soils from 13 sites were divided into three groups. The sand percentage of soils were much higher as above 90% than silt and clay percentages of soils at the all sites. Soil texture was classified sandy (10 sites) and loamy sand (3 sites). In distribution characteristics at different soil particles according to direction, large particles ($>500{\mu}m$) were higher in the order of Group 1 (Marian cove coast regions) > Group 2 (Inland regions) > Group 3 (Maxwell bay coast regions). On the other hand, small particles ($<355{\mu}m$) were higher in the order of Group 3 > Group 2 > Group 1. Chemical characteristic of soils showed significant differences at different areas. pH ranged 4.5-6.7, showing it was slightly acid and EC ranged $0.06-0.16dS\;m^{-1}$. T-N, OM and T-C contents were high at #6, #8, #12 and #13 sites. T-P and P2O5 contents were high at #9 and #12 sites. The results of this study will be helpful to understand soil environment in the Antarctic Peninsula and surrounding islands.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.794-800
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• 2011

To develop biochar for soil conditioner using water plants, characteristics of nutrients release of biochars were investigated under different water plants, manufacturing times and manufacturing temperatures. Under different water plants for manufacturing biochar, the concentrations of T-N and $P_2O_5$ in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. The concentrations of $K_2O$ in the water were in the order of TYHOR ${\fallingdotseq}$ CRXDM > ZIZLA > PHRCO > MISSA. Under different manufacturing times for biochar, the concentrations of T-N, $P_2O_5$ and $K_2O$ in the water with biochars were higher in the order of 2 hr > 30 min ${\fallingdotseq}$ 1 hr. The concentrations of T-N, $P_2O_5$ and $K_2O$ in the water with biochars were on the order of $350^{\circ}C$ > $500^{\circ}C$ > $600^{\circ}C$ under different manufacturing temperatures. Total amounts of T-N and $K_2O$ releases in the water with biochars were higher in the order of CRXDM > ZIZLA > PHRCO > TYHOR > MISSA. Using biochars by water plants, total amounts of $P_2O_5$ releases in the water with biochars were on the order of CRXDM > ZIZLA > MISSA >PHRCO > TYHOR. The results of this study suggest that biochars by water plants can supply some of the nutrient requirements of crops and can be a valuable fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1095-1102
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• 2011

The effect of mixed cultivation with green manure crops and liquid pig manure on rice growth was investigated. Field experiment in site 1 (Astragalus sinicus L.) and site 2 (Lolium multiflorum Lam.) were designed with control (non-green manure crop), PLM 100 (non-green manure crop + liquid pig manure 100%), A(L)PLM 0 (green manure crop + PLM 0%), A(L)PLM 50 (green manure crop + PLM 50%), A(L)PLM 75 (green manure crop + PLM 75%), and A(L)PLM 100 (green manure crop + PLM 100%). The results of 1,000 grain in rice plant were in the order of APLM 100 ${\geqq}$ APLM 75 ${\fallingdotseq}$ PLM 100 ${\fallingdotseq}$ APLM 0 ${\fallingdotseq}$ APLM 50 ${\fallingdotseq}$ control for site 1 and LPLM 100 ${\geqq}$ LPLM 75 = LPLM 50 = PLM 100 ${\geqq}$ LPLM 0 ${\fallingdotseq}$ control for site 2. The yields of rice in site 1 and site 2 were $636kg\;10a^{-1}$ (increasing yield 10%) for APLM 100 and $775kg\;10a^{-1}$ (increasing yield 12%) for LPLM 100, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.465-472
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• 2011

To investigate the effect of inorganic ($GeO_2$) and organic (Ge-132) germanium treatment on Brasica juncea C. plant, growth characteristics and Ge contents were examined with various inorganic or organic germanium treatments (0, 5, 10, 25, 50, 75 and $100mg\;L^{-1}$), respectively. Brasica juncea C. growth did not much inhibited until Ge $10mg\;L^{-1}$ concentration under both Ge-132 and $GeO_2$ treatments as compared to control. On the other hand, at Ge concentration higher than $25mg\;L^{-1}$ concentration, Brasica juncea C. growth was inhibited under both Ge-132 and $GeO_2$ treatments. Under treatment of $GeO_2$, length of root and shoot slightly increased until $5mg\;L^{-1}$ concentration and dry weight slightly increased until $10mg\;L^{-1}$ concentration. Under treatment of Ge-132, length of root and shoot slightly increased until $10mg\;L^{-1}$ concentration and dry weight slightly increased until $25mg\;L^{-1}$ concentration. Total Ge contents in Brasica juncea C. early seedlings with $GeO_2$ treatment were a bit higher than those with Ge-132 treatment. Germanium was primarily accumulated in the roots (77%) with organic Ge (Ge-132) treatments, whereas Ge was primarily accumulated in the leaf (70%, respectively) with $GeO_2$ treatments. The Ge uptake rates in inorganic Ge treatments were slightly high than those in organic Ge treatments. Under inorganic Ge treatment with $2.5mg\;L^{-1}$, about 3% of Ge was accumulated into plant and distribution in leaf and root was 84.8% and 15.2%, respectively. Under organic Ge treatment with $2.5mg\;L^{-1}$, about 2.6% of Ge was accumulated into plant and distribution in leaf and root was 66.4% and 33.6%, respectively.