• Korean Journal of Weed Science
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• v.16 no.2
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• pp.100-107
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• 1996

Pre- and post-emergent control of Aneilema keisak was investigated in no-till paddy fields. In addition, a pot trial was conducted to determine use rates of the experimental post-emergent herbicide LGC40863. For pre-emergent control, butachlor(1,800g ai/ha), pretilachlor(600g ai/ha), pretilachlor plus pyrazosulfuron(300+18g ai/ha, respectively), thiobencarb plus bensulfuron(2,100+51g ai/ha, respectively), and molinate plus pyrazosulfuron(1,500+21g ai/ha, repectively) were treated at 20 days before seeding. Among the herbicides, molinate plus pyrazosulfuron was the least effective (23% control), while all other herbicides provided excellent(>95%) control of A. keisak. None of these herbicides caused rice phytotoxicity. However, rice yield in the plot treated with molinate plus pyrazosulfuron decreased about 50% due to poor A. keisak control. LGC40863 controlled A. keisak completely, by foliar application, across wide growth stages from the 5- to 15-leaf at 50g ai/ha in pot tests. In the field, treatment of LGC40863(30 to 50g ai/ha) provided >95% control of A. keisak when treated either at 15 days after transplanting or at non-productive tillering stage. Efficacy of 2,4-D and bentazon was insufficient when treated at non-productive tillering stage. These results suggest that, in no-till paddy fields, A. keisak is controlled by pre-emergent application of butachlor, pretilachlor, pretilachlor plus pyrazosulfuron, or thiobencarb plus bensulfuron, and by post-emergent application of LGC40863.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.7
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• pp.53-63
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• 2002

Runoff, sediments and nutrient losses were studied under different patterns of paddy field management: (1) fall and spring plowing (Plowing)i (2) fall plowing for half of plot and spring plowing (Semi-plowing); (3) no-till for fall and spring plowing (Un-plowing) during the non-cropping period in the southern Korea for two years. The runoff amount and initial abstract were significantly affected by plowing practices. Un-plowing plot showed the highest runoff amount among treatments. The concentrations of sediment from Plowing plot were much higher than those from Un-plowing plot, especially after (all plowing. Sediment losses from Plowing plot were 25% more than those from Un-plowing plot. There was significant difference in nutrient losses via runoff water and sediment according to plowing practice. Two-year average of losses of N from paddy field during non-cropping period were 9.42 kg ha$\^$-1/, 8.17kg ha$\^$-1/, and 7.76 kg ha$\^$-l/ for Un-plowing, Semi-plowing, and Plowing plot, respectively, while losses of P were 0.64 kg ha$\^$-1/, 0.58 kg ha$\^$-1/, and 0.58 kg ha$\^$-1/ for each tillage system. Losses of total-N, ammonia-N, nitrate-N, Total-P from Un-plowing plot was larger than those from Plowing and Semi-plowing plots during study period.

• Journal of Environmental Science International
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• v.22 no.11
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• pp.1509-1517
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• 2013

So far, most studies associated with soil carbon sequestration have been focused on long term aspect. However, information regarding soil carbon sequestration in short term aspect is limited. This study was conducted to determine changes of soil organic carbon content and stability of carbon in response to compost application rate and tillage management during rice growing season(150 days) in short term aspect. Under pot experiment condition, compost was mixed with an arable soil at rates corresponding to 0, 6, 12, and 24 Mg/ha. To determine effect of tillage on soil carbon sequestration, till and no-till treatments were set up in soils amended with application rate of 12 Mg/ha. Compost application and tillage management did not significantly affect soil organic carbon(SOC) content in soil at harvest time. Bulk density of soil was not changed significantly with compost application and tillage management. These might result from short duration of experiment. While hot water extractable organic carbon(HWEOC) content decreased with compost application, humic substances(HS) increased. Below ground biomass of rice increased with application of compost and till operation. From the above results, continuos application of compost and reduce tillage might improve increase in soil organic carbon content and stability of carbon in long term aspect.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.191-196
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• 1998

This experiment was conducted to investigate the mulch effect of rice straw and dead water foxtail treated with herbicides on weed germination, seedling establishment, and early growth of rice under the no-till culture condition. The percent seedling establishment of rice straw + dead water foxtail mulch was decreased significantly compared to rice straw mulch and non-mulch. Rice straw mulch and rice straw + dead water foxtail mulch inhibited the early growth of no-till direct seeded rice remarkably. However, they promoted rice growth after active tillering stage. Rice straw mulch and rice straw+dead water foxtail mulch in no-till direct seeding decreased weed occurrence significantly. The control value of barnyardgrass, compared with non-mulch, was 96.5% in the rice straw mulch and 75.6% in the rice straw + dead water foxtail mulch, respectively. The pH and concentration of dissolved oxygen in irrigated water were reduced significantly by both rice straw mulch and rice straw+dead water foxtail mulch during early rice growth stage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2003.10a
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• pp.124-125
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• 2003

• Korean journal of applied entomology
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• v.16 no.1 s.30
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• pp.7-12
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• 1977

In order to find out the optimum weeding date for growing barley in paddy field, several kinds of weeding dates and frequencies were made and compared. The results are summarized as follows: 1. As far as the weeding frequencies were fixed with one time, an immediate weeding after wintering resulted better barley grain yield and yield components by causing decreased yield of weed. 2. Maximum allowable date to be free from the weed competition were estimated as not late than February 10 or at most february 25. 3. It is considerable that the effect of weeding was continuously found till March 11 but no significant weeding effect was found when the weeding was done after April. 4. The competition of weed and barley was relatively so higher from February 25 to March 30 that the control during this period seemed to be very effective by causing little decrease in barley grain yield. 5. Major overdominant weeds observed in the paddy field for barley growing period were Alopecurus aequalis S., Stellaria alsine G., and Galium aparin L., in the order of degrees.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.371-374
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• 2011

The objectives of the present study evaluated aquatic animals on the water in a rice field. Field investigation was carried out in conventional tillage without rice straw or green manure crop treatment (CTFS, check plot), no-tillage without cover crops (NTNT), no-tillage amended with rape (NTRA), no-tillage amended with rye (NTRY), no-tillage amended with hairyvetch (NTHV), and no-tillage amended with Chinese milk vetch (NTCM). Total dense population of aquatic animals in HTHV was significantly higher than the other plots (p<0.05) on May 30. Dense populations of Daphniidae and Culicidae on June 20 were lowest in CTFS compared to no-tillage plots (p<0.05). Furthermore, in principal component analysis (PCA), PC1 explained 44.9% of variance, whereas PC2 explained 26%, for a cumulative total of 70.9% and the PC1 of the PCA separated the samples from NT treatments and CFS (p<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.3
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• pp.375-379
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• 2011

This study was conducted to evaluate the effect of rice cover crop cropping systems on rice root growth in a rice field as affected by conventional tillage without rice straw or green manure crop treatment (CTFS, check plot), no-tillage without cover crops (NTNT), no-tillage amended with rape (NTRA), no-tillage amended with rye (NTRY), no-tillage amended with hairyvetch (NTHV), and no-tillage amended with Chinese milk vetch (NTCM). In 0-5 cm soil depth, dry weight of root in NTRS ($128g\;m^{-2}$) was significantly higher than in the other plots (p<0.05) at harvesting stage. In addition, content of active organic matter at 0-5 cm soil depth was $1,684g\;m^{-2}$ in NTCM, $1,309g\;m^{-2}$ in NTRA, $1,295g\;m^{-2}$ in NTRS, $1,072g\;m^{-2}$ in NTRY, $917g\;m^{-2}$ in NTHV, $434g\;m^{-2}$ CTFS, and $426g\;m^{-2}$ in NTNT treatment. In no-tillage rice cover crop cropping system, our findings suggest that NTRS and NTCM should be enhanced root growth and active organic matter in paddy field.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.1
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• pp.105-112
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• 2010

Applications of plant residues and green manures generally improve the properties of soil under conventional farming system. Therefore, we investigated the improvement of selected soil physical properties, bulk density, porosity, and water content, soil penetration resistance, and soil microbial biomass carbon (SMBC) content as affected by different management practices: 1) conventional tillage without rice straw or green manure crop treatment (TNT, check plot), 2) no-tillage amended with rice straw (NTRS), 3) no-tillage amended with rye (NTR), 4) no-tillage amended with Chinese milk vetch (NTCMV), 5) no-tillage without rice straw or green manure crop treatment (NTNT), The values of bulk density, porosity, and water content ranged from 1.22 to 1.37 Mg $m^3$, from 48.3 to 54.0%, and from 35.0 to 40.2%, respectively. The management practices might positively influence the changes in the selected soil properties, especially in the second experimental year. The soil penetration resistance and SMBC content were also improved after applying rice straw and green manure crops as comparing with TNT. Therefore, applications of the rice straw and green manure crop management practices under no-tillage system positively influenced soil physical properties and soil microbial activities in paddy field.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.209-216
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• 2010

This study was to find out optimum rice cultivars for organic farming in no-tillage paddy. A field research was conducted the yield, yield components, and qualities of thirty two Korean rice cultivars, and two Japanese rice cultivars. The column length of early rice plant was shorter in medium maturing rice cultivars compared to early, and medium-late maturing rice cultivars. Planthopper population per20-plant was lower in Ilpumbyeo, Dongjinbyeo, Hojinbyeo, Donganbyeo, and Sobeebyeo in that order while was higherin rice cultivars of early maturity. The disease severity of sheath blight was higher in Saechucheongbyeo>Chucheongbyeo>Namwonbyeo>Sangmibyeo in that order, on the other hand, that was lowerinHwaseongbyeo>Junambyeo>Saesangjubyeo=Hitomebore>Ilpumbyeo>Hwayeongbyeo in that order, respectively. The grain yield of Korean rice cultivars was significantly higher in 2.95 Mg $ha^{-1}$ for Hwasinbyeo, 2.91 Mg $ha^{-1}$ for Ilpumbyeo, 2.86 Mg $ha^{-1}$ for Sobeebyeo, 2.73 Mg $ha^{-1}$ for Naepungbyeo, and 2.70 Mg $ha^{-1}$ for Saegyehwabyeo compared with 1.38 Mg $ha^{-1}$ for Hwabongbyeo, 1.62 Mg $ha^{-1}$ for Hwayeongbyeo, and 1.78 Mg $ha^{-1}$ for Haepyeongbyeo of medium maturing rice cultivars, respectively. Toyo taste value of medium maturing rice cultivars tended to higher than that of early, and medium-late maturing rice cultivars. Ripening rate of rice cultivars was significantly positive correlated with Toyo taste value while negative correlated with protein content. According to principal component analysis, these results show that Sangmibyeo, Sangsanbyeo, and Odaebyeo for early maturity, Naepungbyeo, and Sobeebyeo for medium maturity, and Hwasinbyeo, Chucheongbyeo, and Sindongjinbyeo for medium-late maturity were optimum rice cultivars for organic farming in no-tillage paddy.