• Journal of Biosystems Engineering
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• v.38 no.2
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• pp.73-80
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• 2013

Purpose: This study was conducted to compare tillage and loads characteristics of three types of rotavators in farmland working condition of Korea. Methods: Tillage operations using three types of rotavators, i.e. rotary-type, crank-type and plow-type, were carried out in a dry field of Korea. The same prime mover tractor was used for driving three types of rotavators, and under several operational conditions, tillage characteristics such as actual working speed, rotavating depth, rotavating width, actual field capacity, flow of tilled soil, soil inversion ratio, and pulverizing ratio were measured. In addition, loads characteristics like torque and required power of Power Take-Off (PTO) shaft were calculated. Results: The average rotavating depth was smaller than the nominal value for all rotavators, and the difference was the greatest in the plow-type rotavator. Nevertheless, the plow-type rotavator showed the largest rotavating depth. The rotavating width was the same as the nominal value of all rotavators. The flow of tilled soil at the same operational conditions was the greatest in the plow-type rotavator and was the smallest in the rotary-type rotavator. In the most commonly used gear conditions of L2 and L3, the average soil pulverizing ratio was the greatest in the rotary-type rotavator, and followed by crank-type and plow-type rotavators in order. In the gear L2 and L3, the plow-type rotavator also had the lowest average soil inversion ratio while the rotary-type and crank-type rotavators had the same soil inversion ratio each other. The average torque and power of PTO shaft in the gear L2 and L3 were the highest in the plow-type rotavator. The load spectra of PTO shaft applying rain flow counting method and Smith-Waston-Topper equation to the measured torque showed that the modified torque amplitude was the greatest in the crank-type rotavator. This may come from the large torque fluctuation of crank-type rotavator during tillage operations. Conclusions: The three types of rotavators had different tillage and loads characteristics. The plow-type rotavator had the deepest rotavating depth, the smallest soil inversion ratio, the largest soil pulverizing ratio and required PTO power. Also, the crank-type rotavator showed a large torque fluctuation because of their unique operational mechanism. This study will help the farmers choose a suitable type of rotavator for effective tillage operations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.346-351
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• 2017

This study was conducted to establish the type and method of fertilization for no-tillage during the third year of No-tillage (NT) and Conventional-tillage (CT) practices, towards different kinds of fertilizers. In this experiment, the livestock manure showed higher in response to fertilizer effects of no-tillage. Comparing growth characteristics and yield in NT and CT. Regarding yield, there is no significant between livestock fertilizer and chemical fertilizer, but between livestock fertilizer and chemical fertilizer in conventional fertilization has significant differences. Based on the result, livestock fertilizer is effective way on the quantity of the crop. Nitrogen absorption of plant in livestock of no-tillage is more effective than conventional fertilization. In case of the phosphorus absorption and potassium absorption of plant, fertilizer effect has no significant. Nitrogen is highly absorbed in livestock fertilization of NT. Absorption of phosphorus and potassium are similar.

• 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.6
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• pp.798-803
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• 2010

Experiments were conducted to find out the optimum amount of compost and tillage depths in pepper cultivation. Red pepper was grown in different plots with 10 cm, 30 cm, and 50 cm in tillage depth, and was applied with 1 ton, 3 ton, and 5 ton $10a^{-1}$, respectively. The pH value in soil showed lower level after experiment than before experiment, however, the contents of the EC, Av. $P_2O_5$, K, Ca, Mg, and Na were increased after experiment. The chemical contents in soil after experiment showed higher level in compost 5 ton $10a^{-1}$. The growth of red pepper in field was enhanced in the compost treatment of 3 ton, 5 ton $10a^{-1}$, and tillage 50 cm plot. In tillage 10 cm plot, yields of red pepper showed the highest amount as 5,880 kg $ha^{-1}$ with compost 3 ton $10a^{-1}$. In tillage 30 cm plot, the yields of red pepper showed the highest as 5,610 kg $ha^{-1}$ with compost 5 ton $10a^{-1}$. The T-N contents and uptake in the red pepper plant increased in the compost in 3 ton $10a^{-1}$ and 5 ton $10a^{-1}$ compared to 1 ton $10a^{-1}$. These results suggest that different amounts of compost should be applied when we cultivate crops with different tillage depth.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.6
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• pp.634-643
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• 2017

No-tillage is an effective practice to save labor input and reduce methane emission from the paddy. Effects of tillage and cultivation methods on carbon accumulation and soil properties were investigated in the treatments of tillage-transplanting (T-T), tillage-wet hill seeding (T-WS), minimum tillage-dry seeding (MT-S) and no-tillage dry seeding (NT-S) of rice. Soil carbon was higher in NT-S and MT-S, compared to T-T and T-WS. In NT-S and MT-S, soil carbon contents were the highest in the top soil (5 cm depth) and decreased with soil depth. In T-T and T-WS, however soil carbon contents showed no significant difference up to soil depth of 15 cm from the top. Carbon content was the highest in the soil particle size under $106{\mu}m$ and decreased as the soil particle size increased. Contents of water-stable aggregates in NT-S and MT-S were higher than those of T-T and T-WS. In NT-S and MT-S, contents of water-stable aggregates were the highest in the top soil and significantly decreased with soil depth while no significant difference up to the soil depth of 15 cm in T-T and T-WS. Available $SiO_2$ contents in the top soil were the highest in NT-S and MT-S while the lowest in T-T and T-WS. It is concluded that minimum or no disturbance of soil in rice cultivation can increase carbon accumulation in the soil, especially in the top layer, and subsequently contribute to the formation of the water-stable soil aggregates.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.551-557
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• 1996

In order to establish a labour-saved and environment friendly paddy rice system in southern Korea, no-tillage paddy system was proposed and investigated from 1992 to 1993. Basically this system includes a complete return of crop residules into the soil, and zero-tillage. In an effort to minimize labour requirement in rice farming, several cultivars were directly sown and grown under the system and the characteristics of the growth and yield potential of the cultivars were compared with those grown in an ordinary paddy soil. Joryeongbyeo, Dongjinbyeo, Daeyabyeo and Calose rices showed high level of seedling establishment in the no-tillage padddy system. However, the value was significantly lower than in those of the cultivars direct-sown in an ordinary tillage paddy condition. The rice direct-sown and grown under the no-tillage paddy system showed significantly decreased number of tillers per square meter and plant height, but increased ripened grains. The lodging-related characteristics of rice plant, such as band breaking weight, the length of top 3rd ∼4th internodes, the height of weight center, and lodging index, were observed positive aspects in cultivars such as Hwasungbyeo, Hwayongbyeo, Joryeongbyeo, Calose and Calose 76 and being considered adaptable to direct-sown under the no-tillage paddy system.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.200-208
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• 2010

The objectives of this study were to evaluate no-tillage cover crop cropping systems for organic farming in paddy. The experiment was performed at Ihyeon series (silt loam: 9.1% sand, 73.0% silt and 17.9% clay) which affected by different management practices. Planthopper population per 20 plant was significantly higher 65.3 for conventional tillage with chemical compounds (control) compared with 3.4~9.6 for no-tillage treatments (without rice straw or green manure, amended with rice straw, hairy vetch, rape, rye, and Chinese milk vetch). Also, disease severity of sheath blight was significantly higher 10.5% for control compared to 0.7~2.9% for no-tillage treatments. Four weed species, namely Monochoria vaginalis, Ludwigia prostrata, Rotala indica, and Aneilema keisak occurred in no-tillage paddy, whereas Monochoria vaginalis occurred in control only. The pH, available phosphate, and microbial biomass C in paddy were steeply decreased in response to submerging, but increased at first heading stage. Soil $NH_4$-N content at first heading stage was significantly higher in no-tillage treatments compared with control. The grain yield was significantly higher in 4.30 Mg $ha^{-1}$ for control than other treatments. Meanwhile, rice productivity was significantly higher in 2.69 Mg $ha^{-1}$ for no-tillage amended with Chinese milk vetch compared to other no-tillage treatments. The number of panicle per plant, grain number perpanicle, and percent ripened grain were highly related for increasing the yield of rice. These results show that Chinese milk vetch was optimum cover crop for organic farming in no-tillage paddy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.259-263
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• 2007

Sowing time of barley after cultivation of rice has frequently been delayed because of rainfall or some other reasons by rice cultivation. Partial tillage direct grain seeder with eight row, which had been developed for rice sowing and showed many advantages in wet field, were tested for barley sowing. After flooding during $2{\sim}3days$, plots were designed to make wet condition. Three sowing methods were tested; high ridged broadcasting, plat drill seeding and partial tillage direct grain seeding. It were impossible to sow properly even in 27% of soil water content by high ridged broadcasting, plat drill seeding but could be possible to sow normally by partial tillage direct grain seeder in 42% of soil water content as good as in 27% of soil water content. Initial growth condition after sowing in plots of partial tillage direct grain seeder were normal even in plots sown in more than 50% of soil water content. No. of spike, which was $508/m^2$, in plot of partial tillage direct grain seeder sowed at 30% soil water content was better than plat drill seeding, $404/m^2$. Yield and yield components of plot of partial tillage direct grain seeder, were higher than plot sowed by plat drill seeder in same soil water content. Partial tillage direct grain seeding can be a good sowing way for barley especially in wet condition. However, parts of seeder have to be improved for barley sowing; 1) ridged width of partial tillage direct grain seeder should be $10{\sim}20cm$ wider than 10 cm, which is necessary for drainage during barley growing season in wet paddy field. 2) sowing width of partial tillage direct grain seeder was not same with one of drill seeder which was the best width for light interception and should be shorter than 30cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.2
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• pp.167-173
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• 2015

Green manure crops are organic materials that can supply organic matter and substitute chemical fertilizer, yet emit methane while being decomposed. Therefore, we experimented with different kinds of Green manure crops and tillage depth in order to decrease the amount of methane emitted when utilizing Green manure crops in paddy soil. The amount of methane emitted during the cultivation period of rice started to increase after transplanting and peaked at 63, and 74 days after transplanting, than decreased to almost none starting from 106 days. According to the kind of Green manure crop, it was highest in barley, then hairy vetch and chemical fertilizer. Depending on the tillage depth, the amount of methane emitted decreased by 22.5% in chemical fertilizer, 12.4% in hairy vetch and 11.7% in barley in 20cm tillage compared to 10cm tillage. The air temperature of methane test period was $30{\sim}40^{\circ}C$, and the soil temperature was more than about $2{\sim}10^{\circ}C$ lower than the air temperature. Due to the irrigation started before transplanting, the oxidation-reduction potential (Eh) of soil was rapidly reduced, and showed negative (-) values. Eh values mostly kept the range of -300~-500 mV during rice cultivation. It rapidly increased 106 days after transplanting. Rice yield the highest in hairy vetch and did not show differences according to tillage depth. Methane emission could be effectively reduced if the paddy soil was tilled by 20 cm during the application of hairy vetch.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.65-74
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• 2020

BACKGROUND: Soil carbon sequestration has been investigated for a long time because of its potential to mitigate the greenhouse effect. No- or reduced tillage, crop rotations, or cover crops have been investigated and practiced to sequester carbon in soils but the roles of soil biota, particularly microorganisms, have been mostly ignored although they affect the amount and stability of soil organic matters. METHODS AND RESULTS: In this study we analyzed the organic matter and microbial community in organically cultivated corn field soils where no-tillage (NT) or conventional tillage (CT) had been practiced for about three years. The amounts of organic matter and recalcitrant carbon pool were 18.3 g/kg dry soil and 4.1 g C/kg dry soil, respectively in NT soils, while they were 12.4 and 2.5, respectively in CT soils. The amounts of RNA and DNA, and the copy numbers of bacterial 16S rRNA genes and fungal ITS sequences were higher in NT soils than in CT soils. No-tillage treatment increased the diversities of soil bacterial and fungal communities and clearly shifted the bacterial and fungal community structures. In NT soils the relative abundances of bacterial phyla known as copiotrophs, Betaproteobacteria and Bacteroidetes, increased while those known as oligotrophs, Acidobacteria and Verrucomicrobia, decreased compared to CT soils. The relative abundance of a fungal phylum, Glomeromycota, whose members are known as arbuscular mycorrhizal fungi, was about two time higher in NT soils than in CT soils, suggesting that the higher amount of organic matter in NT soils is related to its abundance. CONCLUSION: This study shows that no-tillage treatment greatly affects soil microbial abundance and community structure, which may affect the amount and stability of soil organic matter.