Aboveground dry biomass partitioning and nitrogen accumulation in early maturing soybean 'Merlin'

Abstract

The aim of the study was to determine the biomass and nitrogen accumulation in early maturing soybean plants experiencing contrasting weather conditions. Soybean (Glycine max) is a species of agricultural crop plant that is widely described in scientific publications. During 2014-2016, a field experiment with early maturing soybean 'Merlin' was carried out at Grodziec Slaski, Poland (49°48'01" N, 18°52'04" E). Results showed that the morphological traits of the plants, the yield of individual plants, and the soybean crop were all closely related to the climatic conditions. A high amount of precipitation stimulated seed development, resulting in a high production potential. The harvest index calculated for soybean 'Merlin' was high and exceeded 0.5 g g-1. The nitrogen content of the aboveground biomass increased during ontogenesis. The maximum yield of dry matter was noted at the green maturity phase, which subsequently decreased at the full maturity phase because of the loss of the leaf fraction. The variation in the effectiveness of nitrogen accumulation in seeds between 2015 and 2016 was 30%. The nitrogen harvest index values were high in each year of the experiment and exceeded 0.92 g-1. For the production of 1 ton of seeds with an adequate amount of soybean straw, plants needed, on average, 68 kg of nitrogen.