scholarly journals Factors Influencing the Phytotoxicity of Cafenstrole to Transplanted Rice Plants in Paddy Fields.

2001 ◽  
Vol 46 (3) ◽  
pp. 169-174 ◽  
Author(s):  
Mitsuru Kanzaki ◽  
Kazuo Toriu ◽  
Hiromi Oishi ◽  
Norio Shirakawa
2011 ◽  
Vol 45 (24) ◽  
pp. 10524-10530 ◽  
Author(s):  
Fabiane G. Antes ◽  
Eva Krupp ◽  
Erico M. M. Flores ◽  
Valderi L. Dressler ◽  
Joerg Feldmann
Keyword(s):  

1994 ◽  
Vol 353 ◽  
Author(s):  
Shigeo Uchida ◽  
Yasuyuki Muramatsu

AbstractTransfer factors of iodine from soil to rice were obtained by laboratory experiments using 125I tracer. Two typical soil types in Japan, Andosol and Gray lowland soil, were used. The transfer factor (TF) is defined as ’concentration of the nuclide in a plant organ at harvest’ divided by ’concentration of the nuclide in dry soil’. The TFs for brown (hulled) rice were 0.006 for Andosol and 0.002 for Gray lowland soil. The TFs for different organs of rice plants decreased in the order of blade > stem > rachis > unhulled rice >> brown rice.The concentration of iodine in soil solution under flooded conditions varied with time during cultivation. The iodine concentration in rice plants seemed to be influenced by the soil solution.The effect of removal of 1–129 from paddy fields by harvesting rice plants was also modelled. Even assuming continuous deposition of 1–129 onto the field, annual harvesting of the blades and stems of rice plants could effectively reduce the amount of the nuclide in the root zone.


2016 ◽  
Vol 208 ◽  
pp. 562-570 ◽  
Author(s):  
Baolu Yang ◽  
Yuichi Onda ◽  
Yoshifumi Wakiyama ◽  
Kazuya Yoshimura ◽  
Hitoshi Sekimoto ◽  
...  

2013 ◽  
Vol 16 (4) ◽  
pp. 325-334 ◽  
Author(s):  
Shuichi Miyagawa ◽  
Maki Seko ◽  
Mari Harada ◽  
Sengdeaune Sivilay

2007 ◽  
Vol 7 (1) ◽  
pp. 38-43 ◽  
Author(s):  
SEISHU TOJO ◽  
MASAHIRO YOSHIZAWA ◽  
TAKASHI MOTOBAYASHI ◽  
KENGO WATANABE
Keyword(s):  

2020 ◽  
Vol 7 (2) ◽  
pp. 147-154
Author(s):  
Jusran Jusran ◽  
Radite Praeko Agus Setiawan ◽  
I Dewa Made Subrata

Most of paddy fields in Indonesia are not consolidated, therefore, soil hardpan usually did not exist.  With no soil hardpan, mobility of any machine for crop maintenance is very difficult even in some places is almost impossible.Until now crop maintenance such as weeding, spraying and spreading fertilizer was done manually by labor. Then mechanization is required to replace the labour which is not available or very expensive. Hence, this study conducted with objective to make a prototype II of a single wheel tractor  for crop maintenance operated in deep mud field or in an unconsolidated paddy field. The study also did performance test of a single wheel tractor to measure the tractor speed, traction, sinkage, and slip of wheel  when operated in rice plants field. The results of performance test showed that the speed average of wheel with straight lug and curved lug were 1.15km/hour and 0.97 km/hour. The average of sinkage and slip both of wheels with straight lug and curved lug respectively were 24.8 cm, 25.9 cm and 38.7 %, 26.12%. The results of performance test olso showed that the traction average of wheel with straight lug and curved lug respectively were 45.8 kg and 41.5 kg


Author(s):  
Y. Yamada

Kim and van Zyl (2001) proposed a kind of radar vegetation index (RVI). RVI = 4*min(λ1, λ2, λ3) / (λ1 + λ2 + λ3) They modified the equation as follows. (2009) RVI = 8 * σ<sup>0</sup>hv / (σ<sup>0</sup>hh + σ<sup>0</sup>vv +σ<sup>0</sup>hv ) by L-band full-polarimetric SAR data. They applied it into rice crop and soybean. (Y.Kim, T.Jackson et al., 2012) They compared RVI for L-, C- and X-bands to crop growth data, LAI and NDVI. They found L-band RVI was well correlated with Vegetation Water Content, LAI and NDVI. But the field data were collected by the multifrequency polarimetric scatterometer. The platform height was 4.16 meters from the ground. The author tried to apply the method to actual paddy fields near Tsukuba science city in Japan using ALOS/PALSAR, full-polarimetry L-band SAR data. The staple crop in Eastern Asia is rice and paddy fields are dominant land use. A rice-planting machine comes into wide use in this areas. The young rice plants were bedded regularly ridged line in the paddy fields by the machine. The space between two ridges of rice plants is about 30 cm and the wave length of PALSAR sensor is about 23 cm. Hence the Bragg scattering will appear depending upon the direction of the ridges of paddy fields. Once the Bragg scattering occurs, the backscattering values from the pixels should be very high comparing the surrounding region. Therefore the radar vegetation index (RVI) would be saturated. The RVI did not follow the increasing of vegetation anymore. Japan has launched ALOS-2 satellite and it has PALSAR-2, L-band SAR. Therefore RVI application product by PALSAR-2 will be watched with deep interest.


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