Growth, yield and composition of four winter cereals. 2. Nitrogen and carbon economy.

A field experiment with 3 cultivars each of wheat, rye, triticale and barley, grown at a density of about 320 plants/m, was conducted in 1986 on a fertile clay soil at East Flevoland, Netherlands. N at 120 kg/ha for wheat and triticale and 60 kg/ha for rye and barley was split-dressed in 2 applications. N yield was highest in wheat (196 kg/ha) and lowest in rye (123 kg/ha). The amounts taken up were influenced by the N rate. The triticale cv. Lasko and the barley cv. Marinka had a higher N-uptake than the other triticale and barley cultivars. N harvest index (i.e. the ratio of N in grains and N in above-ground DM at final harvest) was lowest in rye and highest in barley. N concentration in plant organs (grains, chaff, leaves, stems and roots) was higher in wheat and triticale than in rye and barley. This was probably caused by the difference in the level of N application. N use efficiency, expressed as grain DM production/kg N taken up, was 53 in wheat, 68 in rye, 50 in triticale and 61 in barley. In all species, the largest reserves of water-soluble carbohydrates (WSC) were found in the stems. Rye allocated more dry matter to stem growth before flowering than wheat, triticale and barley. Averaged over these cereals, 26% of WSC, produced before flowering, was used for redistribution and respiration during grain production