• Agricultural and Biosystems Engineering
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• v.6 no.2
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• pp.59-64
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• 2005

In the study, the cone index, the cohesion and the internal resistant angle of soil were measured before and after tillage in order to suggest relative improvement in soil properties. The tillage methods tested in the study were five combinations of plow and rotary tillage operation and the experiments were performed on five selected test fields. The maximum tillage depth was 20 cm under the ground. The CIs for all the tillage operations were improved in comparison with those before tillage. The best combination of tillage operations for improving the CIs of soil was one plow operation followed by one rotary. After applying the tillage operations, the internal resistance angle reduced by 7-8 degree and the cohesion decreased up to about $1N/cm^2$ in comparison with those before tillage. We concluded that the cone index, the cohesion and the internal resistant angle of soil could be used as measures for representing the relative degree of tillage for a specific tillage operation. In addition, the study was useful as a basic research tool for developing an decision making system that determines an optimal tillage method with soil properties.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.4
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• pp.326-329
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• 2007

Quantifying soil organic carbon (SOC) has long been considered to improve our understanding of soil productivity, soil carbon dynamics, and soil quality. And also SOC could contribute as a major soil management factor for prescribing fertilizers and controlling of soil erosion and runoff. Reducing tillage intensity has been recommended to sequester SOC into soil. On the other hand, determination of traditional SOC could barely identify the tillage practices effect. Physical soil fractionation has been reported to improve interpretation of soil tillage practices impact on SOC dynamics. However, most of these researches were focused onupland soils and few researches were conducted on paddy soils. Therefore, the objective of this research was to evaluate paddy soil tillage impact on SOC by physical soil fractionation. Soils were sampled in conventional-tillage (CT), partial-tillage (PT), no-tillage (NT), and shallow-tillage (ST)plots at the National Institute of Crop Science research farm. Samples were obtained at the three sampling depth with 7.5-cm increment from the surface and were sieved with 0.25- and 0.053-mm screen. Soil organic carbon was determined by wet combustion method. Significant difference of SOC contentwas found among sampling soil depth and soil particle size. SOC content tended to increase at the ST plot with increasing size of soil particle fraction. We conclude that quantifying soil organic carbon by physical soil particle fractionation could improve understanding of SOC dynamics by soil tillage practices.

• 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.48 no.4
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• pp.285-294
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• 2015

Ordination has been recognized useful method to analyze the effects of multiple environmental factors on dozens of species in vegetation ecology because of summarizing community data by producing a low-dimensional graphics. Main objective of this study was the application of ordination method, especially principal components analysis (PCA), to analyze the soil characterization on paddy treated by different green manure crops and tillage methods. Treatments included the three tillage treatments and two green manure crops as the following; (i) moldrotary + rotary tillage without green manure crop (Con), with (ii) hairy vetch (ConHv), and (iii) hairy vetch + green barely (ConHvGb), (iv) rotary tillage without green manure crop (Rot), with (v) hairy vetch (RotHv), and (vi) hairy vetch + green barly (RotHvGb), and (vii) no-tillage (Notill). Vectorial distance result from PCA of soil properties including physical, chemical, and microbial properties showed the two main difference. Firstly, soil properties among plots without green manure were strongly affected by tillage strength [Vectorial distance: Con-Notil (5.88) > Rot-Notill (4.58)] at PC1 (35.0%) axis. But it was difficult to find the fixed trend among plots when green manure crop was added in plot. Nevertheless, two groups were separated by adding green manure crop at PC2 (29.2%) axis. These results show that PCA ordination methods could be used the research for change of soil characterization.

• Korean Journal of Organic Agriculture
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• v.11 no.1
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• pp.79-88
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• 2003

Saved labor cost, energy conservation, reduced soil erosion, and increase of emergence rate would be expected from no-tillage cultivation of corn. Few research has been reported on the no-tillage effects for waxy corn hybrid. Five waxy com hybrids were tested under conventional and no-tillage practices to investigate responses of early growth, plant characters, ear characters, fresh yield, and grain yield. Emergence rates under no-tillage were lower than under conventional tillage. Plant heights at early growth stages under no-tillage were higher than those under conventional tillage. Plant height under no-tillage was higher than that under conventional tillage. There were no differences between conventional tillage and no-tillage for ear length, number of kernel rows, number of kernels per row, 100 kernels weight, fresh yield, and grain yield. This result indicates that no-tillage practice might be recommended for practical method for waxy com production. Days to tasseling and silking, plant height, ear height, ear length, and number of kernels per row were correlated with fresh and grain yields.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.5
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• pp.285-292
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• 2008

To investigate the effect of tillage methods on the silage barely growth and the soil environment in paddy field, liquid pig manure(LPM) was applied after harvesting rice at Jisan series soil for 2 years. Five plots, a LPM applied rate as N%; 0, 100, 150, 200(basal dressing) and 100(basal dressing)+50(additional fertilizer) were divided by tillage methods; non-tillage, non-tillage+rice straw and rotary tillage method. Emission amounts of $NH_3$ gas highly decreased in the rotary tillage and the non-tillage+rice straw plot compared to non-tillage plot. The contents of soil organic matter and exchangeable cation were increased in the applied LPM plot. $NH_4-N$ and $NO_3-N$ contents in soil were the highest in the non-tillage+rice straw plot and followed by the rotary tillage and highly decreased along with the growth of plant. Run-off rate of mineral components were higher in order of the rotary tillage plot£æthe non-tillage plot£æthe non-tillage+rice straw plot and then leached to $SO_4$, $NO_3-N$, K plentifully. The yield of silage barley in dry weight was higher in order of the non-tillage+rice straw plot>the rotary tillage plot>the non-tillage plot. To estimate the feed value of silage barley, crude protein, acid detergent fiber(ADF) and neutral detergent fiber(NDF) contents were analyzed. Crude protein and ADF contents were the highest at rotary tillage N150% plot as 9.7 and 29.4%, respectively. NDF contents was the highest at non-tillage+rice straw N150% plot as 56.7%. In conclusion, we recommend not to incinerate rice straw and to apply LPM at non-tillage status in cultivating the silage barley. This may prevent water pollution and increase barley yields.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.593-598
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• 2006

This study was conducted to investigate the effect of tillage methods such as plowing and rotary tillage (PRT), rotary tillage (RTG), no-tillage after barley straw application (NTB), and barley straw mulching after plowing and rotary tillage (BPR) on the growth and the yield of soybean when cultivated after the cultivation of barley. The methods were compared with the control method in which plowing and rotary tillage after barley straw incineration was applied. Barley straw application resulted in increase in organic matter, total nitrogen, phosphate, and exchangeable cation regardless of tillage methods. Porosity and moisture level in paddy soil was ranked as follows : PRT > RTG > BPR > control > NTB. Decomposition rate of barley straw dramatically increased to 41.7% toward 30 days after soybean sowing, higher in NTB, DRB, and RTG than in BPR. Weed occurrence was decreased 36% in NTB and 40% in BPR. Root activity, nodulation and the dry weight per plant of soybean at flowering stage were highest in NTB and lowest in PRT. Soybean yield in NTB was 3,070 kg/ha increasing 19%, whereas that in PRT was not increased. Therefore in case of a frequent rain during the cultivation of soybean in paddy field PRT could result in excess moisture level in soil, the cultivation without tillage is desirable.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.510-518
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• 2013

Corn was mainly cultivated in slope land during summer season when heavy rain falls so that soil loss occurs severely. Especially, soil disturbance and exposure of topsoil by conventional tillage intensifies soil loss by heavy rain. The aim of this study was to develop surface covering and tillage methods for reducing soil loss in corn cultivation. The experiment was conducted in 17% sloped lysimeter with 8 treatments including strip tillage after surface covering with rye residue, strip tillage after residue covering of several crops and sod culture, black polyethylene film covering after conventional tillage and control. Amount of runoff water and eroded soil, and corn growth were investigated. Amounts of runoff water in all plots except black polyethylene plot ranged from 152 to 375 $m^3\;ha^{-1}$, accounting for 13~32% of 1,158 $m^3\;ha^{-1}$ in control. Amount of eroded soil decreased by 94 to 99% (3 to 89 kg $ha^{-1}$) in plots of strip tillage after covering with crop residues compared to control with 1,739 kg $ha^{-1}$. Corn yields in plots of strip tillage after covering with crop residues ranged from 6.0 to 6.9 Mg $ha^{-1}$, while that of control was 6.5 Mg $ha^{-1}$. The results suggest that strip tillage methods after surface covering with crop residues are very effective on soil conservation of slope land in corn cultivation.

• Journal of Drive and Control
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• v.16 no.4
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• pp.23-31
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• 2019

The purpose of this study was to evaluate the PTO severeness for an agricultural tractor during disk plow and rotary tillage. The PTO load measurement system was constructed with data acquisition and a PTO torquemeter. Field experiments were conducted at a combination of traveling speed (L3 Low, L3 High) and PTO speed (P1, P2). The load spectrum was generated using the rain-flow counting method, and the SWT method was used to consider the range and mean of the PTO load. The damage sum was calculated by applying a modified miner rule, which is a cumulative damage law. The relative severeness was expressed as the ratio of the lowest damage sum. Relative severeness was higher with the lower PTO gear stage, and higher driving gear stage and it was approximately 40-102 times higher for rotary tillage than disk plow tillage in the same gear stages. The relative severeness was 1010.12 in the rotary tillage under L3 High P1 based on the disk plow tillage under L3 Low P2.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.319-319
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• 2017

Methane is the main greenhouse gas released from rice paddy field. Methane from paddy fields accounts for 11 % of the global total methane emission. The global warming potential (GWP) of methane is 25 times more than that of carbon dioxide on a mass basis. It is well known that most effective practice to mitigate methane in paddy is related to the water management during rice growing season and the use of organic matters. This study was conducted to investigate the effects of tillage and cultivation method on methane emission in paddy. Tillage (tillage and no-tillage) and cultivation methods (transplanting and direct seeding) were combined tillage-transplanting (T-T), tillage-wet hill seeding (T-W), tillage-dry seeding (T-D) and no-till dry seeding (NT-D) to evaluate methane mitigation efficiency. Daily methane emission was decreased on seeding treatments (T-W, T-D, NT-D) than transplanting treatment (T-T). Amount of methane emission during rice growing season is highest in T-T ($411.7CH_4\;kg\;ha^{-1}y^{-1}$) and lowest in NT-D treatment (89.7). In T-W and T-D treatments, methane emissions were significantly decreased by 36 and 51 % respectively compared with T-T. Methane emissions were highly correlated with the dry weight of whole rice plant ($R^2=0.62{\sim}0.93$). T-T treatment showed highest $R^2$ (0.93) among the four treatments. Rice grain yields did not significantly differ with the tillage and cultivation methods used. These results suggest that direct seeding practice in rice production could mitigate the methane emissions without loss in grain yield.