Influence of irrigation and nitrogen fertilization on grain yield and some baking quality characteristics of spring wheat

Authors

• Paavo Elonen Agricultural Research Centre, Department of Soil Science, 01301 Vantaa
• Sirkka-Liisa Rinne Agricultural Research Centre, Department of Soil Science, 01301 Vantaa
• Hilkka Suomela University of Helsinki, Department of Plant Husbandry, 00710 Helsinki

DOI: https://doi.org/10.23986/afsci.71845

Abstract

In the years 1967—70 twelve irrigation experiments of spring wheat were carried out in southern Finland (60-62° N, 22-26° E). Sprinkler irrigation (2 X 30 mm) increased the grain yields on an average by 1240±470kg/ha (from 2740 to 3980 kg) or 45±17 %. The increases in yield were significant on clay soils (9 trials) and loam (1 trial) but insignificant on fines and (1 trial) and mould (1 trial). Additional nitrogen fertilization (from 76 to 143kg/ha N) increased the grain yields on an average by 350± 200 kg/ha or 11±6 %. The ripening of wheat was significantly promoted by irrigation in one year but slightly retarded in three years. Nitrogen fertilization slightly retarded ripening every year The falling number of grains tended to be slightly improved by irrigation (from 285 to 321, on an average), but in most trials irrigation and nitrogen fertilization had no significant influence on the falling number. Irrigation decreased the crude protein content of grains in all trials, on an average by 2.2 ± 0.7 %-units (from 16.3 to 14.1%). This unfavourable effect was, however, avoided with additional nitrogen which increased the protein content by 1.9±0.4%-units (from 14,3 to 16.2 %). The effects of irrigation and nitrogen fertilization on those characteristics of wheat that are correlated with protein, were similar to the effects on the protein content. Thus, irrigation decreased the zeleny value (from 64 to 53 ml), cold viscosity (from 214 to 114 seconds), water absorption (from 66.5 to 64.9 %) and the valorimeter value (from 68 to 60), while these characteristics were improved by nitrogen fertilization. Irrigation did not decrease the Pelshenke value but increased significantly the ratio of the Pelshenke value/protein content (from 5,1 to 6.1). This indicates that the quality of protein was improved by irrigation, while the effect of nitrogen fertilization was the reverse. In fact, irrigation and additional nitrogen fertilization affected the quantity and quality of protein and the baking quality characteristics of wheat in opposite directions but the quantity of grain yield in the same direction. With these two methods combined it was possible to produce 60 % higher grain yields without any noteworthy changes in the baking quality characteristics of spring wheat.