Nitrogen Utilization in the Supernodulating Soybean Variety “Sakukei 4” and Its Parental Varieties,“Enrei” and “Tamahomare”

Control of Soybean Nodule Formation by a Crack Fertilization Technique

“…In fact, supernodulation studies indicated that the super-nodulation itself does not promise the high yielding of the soybean due to the higher competition between nodule and seed. Nakamura et al (2010) recently showed that the supernodulating Sakukei 4 (presently Kanto 100) could not exceed Enrei or Tamahomare in seed productivity, which was consistent with previous reports (Maekawa et al, 2003;Takahashi et al, 2005). Moreover, waterlogging tolerance, which is one of the major stresses restricting the high yielding of Japanese soybean cultivation, in supernodulating cultivar was analyzed by Jung et al (2008).…”

“…Improvement of soybean yield by a cultivation technique is thus still important considering the present situation of food production in Japan. For example, enhancement of nitrogen fi xation by a cultivation technique, not by the genetic improvement such as the use of supernodulating soybean cultivars (Takahashi et al, , 2005Nakamura et al, 2010), is one of the potential targets to improve soybean yield in Japan. In this paper, we report a new method of enhancing soybean nodulation by a cultivation technique called "crack fertilization" which is a combination of two existing concepts; deep layer fertilization (Takagi et al, 1963;Takahashi et al, 1991;Kaushal et al, 2004Kaushal et al, , 2006Kaushal et al, , 2007Watanabe et al, 2007) and subsoiling during soybean growth (Hamada et al, 2003;Ochiai et al, 2004;Iijima et al, 2005;Honjo et al, 2007).…”

Autoregulation of Nodulation in Soybean Plants

“…The peculiar supernodulating variety of soybean "Sakukei 4" showed the improved growth [24], so it was expected high yield. However, Sakukei 4 could not produce higher seed yield compared with the parental varieties Enrei or Tamahomare, because N use efficiency of Sakukei4 was low [25]. One of the reason of low N efficiency might be nodule formation on distal region of root in Sakukei 4.…”

Continuous Application of Biochar Inoculated with Root Nodule Bacteria to Subsoil Enhances Yield of Soybean by the Nodulation Control using Crack Fertilization Technique

“…Nakamura et al (2010), however, indicated that the supernodulating Sakukei 4 (presently Kanto 100) could not exceed Enrei (parental cultivar) or Tamahomare in seed productivity, despite the inconsistencies of former reports (Maekawa et al, 2003;Takahashi et al, 2005). Moreover, Jung et al (2008) suggested that the supernodulating cultivar Kanto 100 was more susceptible to waterlogging than its normal-nodulating ancestral cultivar, Enrei.…”