Photosynthate and Nitrogen Requirements for Seed Production by Various Crops

Abstract

Seed biochemical composition was the basis for segregating 24 crops into four distinct groups. Nitrogen requirements of pulses and soybeans were so great that sustained seed growth demanded continued nitrogen translocation from vegetative tissues. This translocation must eventually induce senescence in these tissues, restrict the duration of the seed-fill period, and limit seed yield.

Effect of Waterlogging During Vegetative Stage On Growth And Yield in Supernodulating Soybean Cultivar Sakukei 4

“…Soybean seeds accumulate N in large quantities during the seed filling stage. Therefore, a large amount of N accumulated in the vegetative tissues is translocated to seeds; thereby, a rapid decline of leaf N contents occurs, accompanying the decline of photosynthetic capability (Sinclair and de Wit, 1975). This self-destructive N translocation is one factor defining the seed yield of soybean.…”

“…Soybean characteristically requires more N for growth than other major crops (Sinclair and de Wit, 1975). Soybean seeds accumulate N in large quantities during the seed filling stage.…”

“…This self-destructive N translocation is one factor defining the seed yield of soybean. In addition, lack of redistributed N from vegetative plant parts might limit yield by restricting the seed-filling duration (Sinclair and de Wit, 1975;Boote, 1981;Egli et al, 1984). One effective option for enhancing the N supply to plants is increasing application of N fertilizers, either as basal application or as top-dressing during growth (Yoshida, 1979;Watanabe et al, 1983).…”

Effects of Pod Removal on Metabolism and Senescence of Nodulating and Nonnodulating Soybean Isolines

“…Further studies of effects of pod removal on soybean senescence led Nooden (15) to conclude that a senescence factor, produced in the seed late in the reproductive phase, caused leaf senescence. In contrst, Sinclair and DeWit (16) sugested that the high N requirement of soybean seeds led to a depletion of vegetative N which caused plants to 'self-destruct' due to lack of N.…”

Effects of Short-Term Waterlogging on Soybean Nodule Nitrogen Fixation at Different Soil Reductions and Temperatures

“…Soybean is physiologically characterized as requiring more nitrogen (N) for grain production than other major crops (Sinclair and de Wit, 1975), because soybean seeds contain a large amount of protein. Since soybean is symbiotic with rhizobia (Bradyrhizobium japonicum), it can fix nitrogen from the atmosphere and utilize it for plant growth.…”