Effects of rate and timing of nitrogen dressings on grain yield formation of winter wheat triticum aestivum cultivar donata
Ellen, J.; Spiertz, J.H.J.
Fertilizer Research 1(3): 177-190
1980
Accession: 005322818
A field experiment with the winter wheat cultivar Donata was carried out on a fine-textured river clay soil in 1978. The rates of N dressing ranged 0-160 kg N/ha and were split into 1-3 application times: autumn, early spring and late spring. Total aboveground dry matter and grain dry weight yields ranged 9.1-13.7 tons/ha and 4.17-6.35 tons/ha, respectively. Late top-dressings increased the harvest index, whereas an autumn dressing had the opposite effect. Number of culms/m2, grain weight (mg) and grain number/m2 increased from 350 to 430, from 35.5 to 36.8 and from 11,680 to 16,980, respectively, as the N dosage was raised from 0 to 160 kg N/ha. The linear rate of grain growth ranged 111-172 kg dry matter/ha per day with N doses from 0 to 160 kg N/ha. Differences in rate of grain growth per unit area were mainly related to number of grains per m2. The association between grain number and grain yield was reflected by a correlation coefficient of 0.97 (n = 32). A higher level of N dressing enhanced the leaf area index and leaf area duration. Total N yield ranged 71-166 kg N/ha and grain N yield 54-122 kg N/ha with N dosages of 0 and 160 kg N/ha, respectively. The N concentration of the grains varied between 1.3 and 2.0 N. An autumn dressing of 40 kg N/ha generally showed only minor effects on yield and yield components. Top-dressings during spring resulted in a higher recovery and efficiency of the applied N. On fertile soils an autumn dressing of N will not be economical, but split-dressings in spring are beneficial. In particular; a late N application during the boot stage increased grain number, harvest index, grain yield and protein concentration of the grain.