Crops characteristics suitable for sustainable agriculture under low fertilizer application

该研究在东京大学研究生院农业和生命科学研究科的大学农场进行。玉米和大麦或小麦在一年内轮换种植。在大麦的情况下，CV。在低肥和薄田条件下，短秆品种Dorirumugi和两个短秆品种的产量没有降低。而高秆小麦品种在施肥条件下易倒伏，在肥沃的土壤中易减产。造成倒伏的因素因品种而异。在玉米上，过量的氮素以硝酸盐形式被吸收并储存在茎中，但这可能会引起小麦和大麦的生长和倒伏。在另一块田地上，小麦在一半施肥量下生长，几乎没有观察到倒伏。在这片土地上，除了玉米外，小麦也存在空间变异，并且这种变异在三年内具有一定的时间稳定性。因此，土壤和肥料中过量营养元素与小麦生长和倒伏的关系有待进一步研究。

The research had been conducted in the University Farm, Graduate School of Agricultural and Life Sciences, The University of Tokyo. Corn and Barley or Wheat were grown in one year rotation. In case of barley, cv. Dorirumugi and two short-culmed varieties, the yield was not reduced even under low fertilizer application and in the infertile field. However, the wheat varieties with high culm tend to lodge with chemical fertilizer application and in the fertile field, and the yield of these varieties reduced in fertile conditions. The factors to cause lodging were various depending on the varieties. In case of corn, excess nitrogen had absorbed and stored in the culm as nitrate form, though it might cause rank growth and lodging in wheat and barley.ln the other field, wheat grew with half amount of fertilizer application, almost no lodging have observed. In this field there were spatial variability of wheat in addition to corn, and the variability was somewhat temporally stable for three years. Therefore, we concluded that the relationship between excess nutritive elements both from soil and fertilizer and growth and/or lodging is necessary to study further.