Split Application of Potassium Improves Yield and End‐Use Quality of Winter Wheat

Abstract

Many studies have investigated the effects of basal K fertilization on the yield and quality of wheat (Triticum aestivum L.). However, less is known about the influence of the split application of K on yield, size distribution of protein fractions, and quality of wheat. Field studies were conducted in two successive seasons (2010/2011 and 2011/2012) using four winter wheat cultivars, Jimai 20, Gaocheng 8901, Yannong 19, and Jinan 17, and three regimes of K fertilization (K0: no K fertilization; KB: basal K fertilization of 120 kg ha−1; KS: basal K fertilization of 60 kg ha−1 plus topdressing of 60 kg ha−1 at jointing). The yield and its components, protein composition, dough‐mixing properties, and bread‐making quality were determined after harvesting. On average, the KS treatments had a yield advantage over KB treatments mainly resulting from higher kernel weight. The KS treatments improved wheat quality resulted in increased glutenin/gliadin ratio, higher polymerization index (the ratio of sodium dodecyl sulfate to insoluble glutenin in total glutenin), and larger glutenin macropolymer (GMP) particles compared to KB fertilization. No differences in the content of crude protein and wet gluten were found between the KS and KB treatments. Dough development time, stability time, and loaf volume were positively correlated with the glutenin/gliadin ratio, polymerization index, and average size of the GMP, respectively. These results suggest that KS can improve the yield and end‐use quality of winter wheat.