@inproceedings{oai:niigata-u.repo.nii.ac.jp:00030876,
 author = {Ohyama, Takuji and Takahashi, Yoshihiko and Nagumo, Yoshifumi and Tanaka, Kazuya and Sueyoshi, Kuni and Ohtake, Norikuni and Ishikawa, Shinji and Kamiyama, Satoshi and Saito, Masaki and Tewari, Kaushal},
 book = {19th World Congress of Soil Science. Division Symposium 3.2 Nutrient best management practices. Soil Solutions for a Changing World, Brisbane, Australia 1-6　August 2010, 19th World Congress of Soil Science. Division Symposium 3.2 Nutrient best management practices. Soil Solutions for a Changing World, Brisbane, Australia 1-6　August 2010},
 month = {},
 note = {Average soybean yield is low compared with the potential yield. N is derived from three sources; N_2 fixation, soil N, and fertilizer N. A heavy supply of N fertilizer often depresses nodule development and N_2 fixation activity, which sometimes results in the reduction of seed yield. We developed a new fertilization technique for soybean cultivation by deep placement (at 20 cm depth from the soil surface) of slow release N fertilizers, coated urea and lime nitrogen (calcium cyanamide) at the rate of 1OOkgN/ha. These treatments consistently promoted seed yield compared with conventional cultivation in the field with various types of soils. Fertilizer N was efficiently used to supplement N during seed filling stage without concomitant depression of nitrogen fixation and nodule growth. In this research, the effect of deep placement of lime nitrogen was evaluated using a rhizobox to investigate the distribution of nodules and roots. The result showed that deep placement of lime nitrogen promoted nodulation in the upper layers of the root system at pod filling stage. The fate of lime nitrogen in soil was investigated by incubation test, and it was suggested that cyanamide is rapidly degraded in 2 weeks, but nitrification was depressed for a long period.},
 pages = {32--35},
 publisher = {19th World Congress of Soil Science, Soil Solutions for a Changing World},
 title = {Deep placement of lime nitrogen promotes nitrogen fixation and seed yield of soybean with efficient utilization rates},
 volume = {19},
 year = {2010}
}