TIME-COURSE OF Nz FIXATION AND ITS CONTRIBUTION TOWARDS N DEMAND IN 'JS-335' SOYBEAN (GLYCINE MAX)
Citation :- TIME-COURSE OF Nz FIXATION AND ITS CONTRIBUTION TOWARDS N DEMAND IN 'JS-335' SOYBEAN (GLYCINE MAX).Legume Research-An International Journal.2005.(28):178 183
The N yield ill soybean increased sharply after 45th day of sowing and attained the maximun level at 85 DAS (days after sowing). The rate of N2 fixation also increased sharply after 45th day and 78% of the total fixed N (111.9 kg/ha) was accrued by the crop during 45–75 DAS. After 75th day, N2 fixation decreased and no significant improvement in the amount of symbiotically fixed N was observed. Soil N uptake, however, increased significantly even after 75th day and its highest level was recorded on 85th day. The contribution towards total N yield by symbiotical1y fixed N decreased from 61.9% at 75 DAS to 54.1% at 85 DAS. The same by soil N increased from 30.4% at 75 DAS to 40.2% at 85 DAS. Symbiotic N2 fixation fulfilled the entire requirement on N only during 55–65 DAS. It was concluded that peak period of N2 fixation was 45–75 DAS in ‘JS 335’ soybean.
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