• Journal of The Korean Society of Grassland and Forage Science
• /
• v.35 no.2
• /
• pp.87-92
• /
• 2015

This experiment was conducted to evaluate the effect of seeding methods and application levels of nitrogen fertilizer on the yield and forage quality of whole crop rice (WCR). The WCR variety "Namil" was directly seeded on April 25 and transplanted on May 25. Five levels of nitrogen fertilizer were applied (90, 110, 140, 170 and 200 kg/ha). There were no significant differences (p<0.05) of the emergence date, heading date and disease resistance based on the nitrogen fertilizer rates; however, the WCR became dark at higher nitrogen fertilizer rates. The plant height increased at higher nitrogen fertilizer rates and the tiller number showed the same trend. In contrast to a direct seeding method, transplanting increased the tiller number. The dry matter (DM) content did not show a certain tendency based on nitrogen fertilizer rates, while the fresh and dry matter yields increased with incremental changes of the nitrogen fertilizer rates (p<0.01), and the transplant method increased the yield size. In yield analysis, the plot direct-seeded with 140 kg N/ha and the transplanting with 170kg N/ha showed the highest yields. The crude protein (CP) content increased with higher nitrogen fertilizer rate, but there was no significant differences between transplant and direct-seeding methods. The content of ADF (acid detergent fiber) and NDF (neutral detergent fiber) increased with higher nitrogen fertilizer rate, but total digestible nutrient (TDN) content decreased with increased nitrogen levels. Although high nitrogen applications increased the fresh and DM yields, the 140 kg/ha nitrogen fertilizer level is recommended as the proper nitrogen fertilizer level, considering both yield and the environments.

• Korean Journal of Environmental Agriculture
• /
• v.31 no.4
• /
• pp.378-380
• /
• 2012

BACKGROUND: In Korea, green manure has been cultivated for reducing chemical fertilizer application, maintaining soil fertility, and feeding livestock in winter season. We evaluated the phosphate balance under green manure-rice cultivating system with different removal rates of green manure for maintaining soil fertility. METHODS AND RESULTS: The barley and hairy vetch mixture was selected as the green manure in this study. The barley and hairy vetch was sowed at a rate of 135 and 23 kg/ha, respectively, without fertilizer application. Total aboveground biomass was 12000 (barley: 5400 kg/ha, hairy vetch: 6600 kg/ha) kg/ha, and these green manure were incorporated with different input rates before rice planting. The input rates of green manure in this study were 0 (NPK+0%), 25 (NPK+25%), 50 (NPK+50%), 75 (NPK+75%) and 100 % (NPK+100) and the standard fertilization (NPK) without green manure cultivation. All treatments were applied with standard fertilizer (N-P-K: 90-19.6-48.3 kg/ha) before rice planting. The highest rice yield was observed in NPK+50% which was 20% higher compared with NPK. The phosphate balance with different incorporation rates of green manure was-104.0,-76.8,-52.9,-27.4, and 6.0 kg/ha for NPK+0%, NPK+25%, NPK+50%, NPK+75%, and NPK+100%, respectively. CONCLUSION(S): The use of green manure for livestock feeding in green manure-rice cropping systems could remove a huge amount of phosphate. This cropping system strongly requires phosphate application before green manure seeding for maintaining soil fertility.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.46 no.6
• /
• pp.473-477
• /
• 2001

Chinese milkvetch (Astragalus sinicus L.) has been traditionally used as a green manure supplying mineral N and organic matters to soil. In rice-Chinese milkvetch interrelay cropping system, three rice cultivating methods (no-till direct seeding, no-till transplanting, and tillage transplanting) were evaluated for stand reestablishment without reseeding Chinese milkvetch with two cropping times (May 25 and June 4) for two years. Chinese milkvetch incorporated was decomposed rapidly in the first week. Decomposition was fast in topsoil than in subsoil. Natural milkvetch reestablishment (NMR), following harvest of no-till-direct-sown rice was good enough to cover the paddy field in both cropping times, but rice yield of this method was lower than that of transplanted rice on paddy field without milkvetch cultivation. Even though good NMR was secured in no-till rice transplanting, the shoot of milkvetch should be removed before machine-transplanting of rice seedlings. NMR was better in rice cropping at the mid-ripening stage of milkvetch (June 4) than at the late-bloom stage (May 25). Rice yield was higher in tillage transplanting at the mid-ripening stage of milkvetch (June 4) than in the other rice cropping method.

• Korean Journal of Soil Science and Fertilizer
• /
• v.27 no.2
• /
• pp.117-124
• /
• 1994

A study was conducted to dectermine the days with optimum soil moisture after drainage or rain for machine workability and seeding establishment on dry seeding in paddy soils(Jeon buk Series, Haplaquepts). The results are summarized as follows. 1. The possible days of tractor-rotary plough were 5days or more for non-mole hole plot(control). The possible days were 2~4days and the optimum days were 5~6days for mole hale plat. 2. The ratio of soil clod(<1cm) was 1 % and 15% for control and mole hole plats, respectively. The optimum soil moisture range for seeding establishment was 31~32% in this soils. 3. The possible days of combine harvesting work were 9days and 5days after drainage for control and mole hole plots, respectively. 4. Soil physical properties were improved but soil organic matter calcium and magnesium in the soil were decreased in the mole hole plats. 5. Yield was 415kg/10a at seeding after 6day drainage in control and 440kg/10a at seeding after 4day drainage in the mole plots.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.4
• /
• pp.360-365
• /
• 1993

The infant seedling of rice(8-to 10-day-old) has often suffered from submergence just after transplanting due to the too short seedling height, 5 to 8cm, This experiment was conducted to elucidate the effect of gibberellic acid($GA_3 : 25% soluble liquid) with the application methods of foliar spray and seed-soaking on the elongation of seedling height of infant rice seedling in machine transplanting, We used a japonica rice variety, Hwaseongbyeo, and the seeding rate was 200g per seed tray(30$\times60$\times3cm). Generally,$GA_3 and Metalaxyl increased the elongation of seedling height of infant seedling while Tetracycle decreased the seedling height, To increase the seedling height of infant seedling, the foliar spary application of $GA_3 was better than seed-soaking treatment. The optimum concentration of $GA_3 for the foliar spray was about l0ppm and the optimum application time of $GA_3 was 3 to 4 days after sowing.

• Korean Journal of Organic Agriculture
• /
• v.16 no.3
• /
• pp.299-308
• /
• 2008

In this study, the effect of commercial organic growth medium amended with different ratios of vermicast on the growth of rice seedlings. The amended ratios of vermicast were 0% (control), 5%, 10%, 20% and 40%, respectively. A bioassay with two rice varieties (Chucheng and Black) was conducted to assesses the amendment effect of vermicast on the seedling growth in two potting methods. In potting treatment, the Chucheng variety with late maturity showed significantly higher values on growth parameters excepted root weight (RW) up to 20% and Black variety with early maturity up to 10% amended with vermicast, respectively. In floor layering treatment, all of the growth parameters significantly increased up to 5% amended with vermicast in both rice variety. The seedling growth of rice in floor layering treatment attained the highest values at lower amended ratios of vermicast than those of potting treated only, it may correspond with increased uptake of nutrient by elongated root grown under the layering amendment of vermicast. Vermicasts can be used as soil amendments or components of plant growth medium for seeding organic agriculture.

• Korean Journal of Weed Science
• /
• v.4 no.1
• /
• pp.26-38
• /
• 1984

To investigate the varietal differences of weed competitive functions under the four different seeding and transplanting methods, rice cultivars, Milyang 23 and Sadominori, were used with the seven weeding methods, namely, weedy check, weed-free, once weeding at 3, 6, 9, and 12 weeks and two times weeding at 3 and 9 weeks after seeding/transplanting, respectively. As a result, the proper and reasonable weeding stages and times by total and respective weed group were estimated. Also the constructive characteristics for yield formations were evaluated under the different competitive conditions as affected by various cropping patterns.

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

• Journal of Biosystems Engineering
• /
• v.37 no.6
• /
• pp.335-341
• /
• 2012

Purpose: While an unmanned helicopter has been extensively used for spraying chemicals on agricultural crops, its low utilization (two months per year from July to August) has recently become an issue. This study aimed to increase the utilization of the unmanned helicopter. The centrifugal rice seeder, a mounting device for rice seeding for unmanned helicopter was developed and assessed its performance. Methods: The concept of the centrifugal spraying device was to obtain design criteria for centrifugal distribution. Four types of blade shapes namely straight, curved, straight wing and curved wing were developed and used. The rotational speed of the blades was tested at 1,000, 1,200 and 1,400 rpm. Results: The blade shapes, rotational blade speed and angle of trajectory were theoretically analyzed and results were validated with a series of laboratory experiments. Conclusions: The curved wing blades provided the distribution uniformity (DU) at 1,200rpm of rotational speed and 60 degree of seed drop point. The spray uniformity of 4.2% was also achieved.

• Proceedings of the Korean Society of Crop Science Conference
• /
• 2001.05a
• /
• pp.96-97
• /
• 2001