Regularity of Nitrogen Accumulation in Soybean and Its Simulation

Nitrogen (N) is considered as an important yield and quality-determining factor in soybean production. The objective of the current experiment was to determine the regularity of N accumulation and its simulation among different varieties. This work was conducted with frame tests (pot without bottom), and three cultivars, HH41, SN14, HN40, and one feed soybean variety MSD was used as materials. The results showed that the regularity of N accumulation in four varieties with the same tendency increased during the whole growth period, which was up to the maximum when the plant was harvested. The longer growth period was, the higher N accumulation of cultivars was, HN40>SN14>HH41, N accumulation of MSD was the highest because of the property for feed soybean. Regularity of N accumulation in plants could be accurately described by the Logistic equation. During the growth there was a period when N accumulation in the whole plant occurred at an intense rate. The time of onset and its duration varied with different varieties. The maximum daily N accumulation was on seed filling stage, pod bearing stage, seed filling stage and pod bearing stage in HH41, SN14, HN40 and MSD, respectively.