• Title/Summary/Keyword: direct-seeded rice

Search Result 167, Processing Time 0.031 seconds

Effect of Seed Coating with Polymers on Seed Vigour and Seedling Stand in Direct Seeded Rice

  • Song, Dong-Seog;Lee, Sheong-Chun
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.43 no.4
    • /
    • pp.214-222
    • /
    • 1998

  • These experiments were conducted to investigate water uptake, electrical conductivity, germination percentage, seedling growth, and seedling establishment rate in direct seeding cultivation of rice. The rice seeds of six japonica type varieties were coated with 12 kinds of polymers in a standard concentration of 0.2% using seed coating machine. The water absorption of the polymer-coated seeds under saturation conditions was not different among varieties, and was the highest in kulcel, maltrin, and waterlock on the polymer-coated seeds. The electrical conductivity with waterlock (55.0 $\mu scm^{-1}g^{-1}$) was higher than the control plot (45.6 $\mu scm^{-1}g^{-1}$) and other treatments. The germination of the polymer-coated seeds was 95.9% at control plot, 92.7% at low temperature and 35.7% at high temperature. The total dry weight of seed decreased in the order of low temperature, control plot, and high temperature, and was effective in pvp (polyvinyl pyrrolidone), opadry, and sacrust. The seedling establishment rate in direct seeding cultivation ranged from 74.9 to 81.0% in flooded paddy surface, and ranged from 64.7 to 76.6% in dry paddy. In both cases, it decreased in the order of early, medium and medium-late varieties, but was enhanced in daran 8600, sepirect, and sacrust. According to this study the recommended polymers for direct seeding cultivation of rice are daran 8600, sepirect, and sacrust.

  • PDF

Distribution and Leaching of Basal Nitrogen in Direct Seeding Rice on Dry Paddy (벼 건답직파 재배에서 기비질소의 토층간 분포와 용탈)

  • 한상준;이호진
    • KOREAN JOURNAL OF CROP SCIENCE
    • /
    • v.42 no.6
    • /
    • pp.752-758
    • /
    • 1997

  • Urea, which is the major nitrogenous fertilizer used in Korea, has been used inefficiently in direct-seeding on dry soil by farmers. This study was conducted to investigate changes in concentrations of basal N within soil layers and its loss during early stage of rice growth. Urea fertilizer was applied in the rates of 7, 5.25, 3.5, 1.75, 0kg- N /10a under direct-seeded rice in dry paddy soil. The concentrations of ammonium and nitrate were determined in soil samples with different depths during period from seeding to the 3rd leaf stage. Futhermore, N leaching was measured in lysimeter designed with pot in greenhouse. ${NH_4}^+ \; and\; {NO_3}^-$ adsorption by soil increased with increasing concentration of added urea and decreased as deeper in soil layers. ${NH_4}^＋$ concentration reached its peak at 7 days after urea application (DAA) and disappeared almostly at 14 DAA. ${NO_3}^-$ reached its peak at 10 DAA and decreased slowly until 14 DAA. ${NO_3}^-$N leaching started next day after urea application and completed until 11 DAA. We concluded that most of basal N applied to direct-seeded paddy was lost by leaching and not useful for rice plant which was in stage of germination. It is urgent need to develop new nitrogen application method for direct-seeding rice on dry soil.

  • PDF

Effect of Rice Straw Treatment and Nitrogen Split Application on Nitrogen Uptake by Direct Seeding on Dry Paddy Rice (벼 건답직파 재배시 볏짚처리 및 질소분시가 질소 흡수에 미치는 영향)

  • Lee, Kyeong-Bo;Kim, Sun-Kwan;Kang, Jong-Gook;Lee, Deog-Bae;Kim, Jong-Gu
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.30 no.4
    • /
    • pp.309-313
    • /
    • 1997

  • Field experiments were conducted on Jeonbug series (Fine silty, mesic family of Aeric Fluventic Haplaquepts), to study the effect of split application of N fertilizer in combination with rice straw on N use efficiency of dry-soil-direct seeded paddy rice. Treatments involved conventional application of N (in three splits; 40% at planting, 30% at five leaf stage and at heading stage) without rice straw, all basal application of N with straw application (5000 kg/ha), N application in two splits (70% at planting and 30% at heading stage) with rice straw application and N application in three splits (40% at planting, 30% at five leaf stage, 30% at heading stage) with application of rice straw. There was Zero N plot too for the estimation of N use efficiency. Seeding was done on dry soil and the filed was flooded 32 days after seeding. The fertilizer application rates were 160, 70, and 80 kg/ha of N, $P_2O_5$ and $K_2O$, respectively. The experiment was conducted for two years, in the same filed. The apparent use efficiency of fertilizer N by rice tended to be higher under the application of rice straw when N was applied in three splits. This, however, did not increase the yield of rice significantly. Even under the application of rice straw, the apparent N use efficiency was lower when N fertilizer was applied in one dose at the planting and in two splits. The lower N use efficiency in these cases, did not yield of rice significantly. The periodical analysis of mineral N in the soil suggested that higher mineral N in the soil at the early stages was responsible for the lower apparent N use efficiency.

  • PDF

Establishment of Control System of Weedy Rice(Oryza sativa) and Barnyardgrass(Echinochloa crus-galli) in Direct-seeded Rice - I. Effect of Oxadiazon, Molinate, Thiobencarb on Control of Red Rice and Barnyardgrass in Water-seeded Rice (벼 직파재배에 있어서 잡초성벼 및 피 방제체계 확립에 관한 연구 - I. 담수표면산파 재배시 앵미와 피에 대한 oxadiazon, molinate, thiobencarb의 파종전 처리 효과)

  • Ryang, H.S.;Kim, J.K.;Kyoung, E.S.;Kim, J.S.;Ma, S.Y.
    • Korean Journal of Weed Science
    • /
    • v.18 no.2
    • /
    • pp.106-115
    • /
    • 1998

  • This study was conducted to investigate the effect of oxadiazon, molinate, thiobencarb before seeding on control of red rice and barnyardgrass in water-seeded rice. High application rate plot among oxadiazon treatment plots could observe phytotoxicity symptoms depending on field conditions, but these injury recovered gradually with time. Molinate and thiobencarb application plots at the concentration of 225~400, 210~420g ai/l0a respectively were not observed phytotoxicity. Control of red rice was different according to kinds of herbicides and application rates. Oxadiazon showed higher control performance at the concentration of more than 60g ai/10a. Control effect of molinate and thiobencarb against red rice was enhanced with the increase of application rate, and both herbicides showed satisfactory effect at more than 300g ai/10a. Control of barnyardgrass showed up to 90~100% in all tested herbicides. There was no significant yield reduction by oxadiazon, molinate, and thiobencarb application before seeding in all tested field. In the pot experiment, crop injury, seedling stand, and early growth were more advantageous at time of drainge after one day after seeding than flooding until rooting.

  • PDF