Effects of applying potassium at different growth stages on dry matter accumulation and yield of winter wheat in different soil-texture fields

Abstract

: To investigate the effects of potassium applying on the grain yield formation of winter wheat, the experiments were carried out on different soil textures with high-yield winter wheat variety Taimai 198. To analyze the effects of potassium application at different stages on winter wheat flag leaf photosynthetic characteristics, dry matter accumulation and distribution, and grain yield under different soil texture conditions, two soil texture test fields [sandy loam (S) and silty loam (F)] and three treatments [no potassium fertilizer (K0), potassium fertilizer base application (100% applicating at sowing, K1), and split application (50% applicating at sowing stage + 50% topdressing at the jointing stage, K2)] was arranged. The results showed that the interaction of soil texture and potassium application significantly affected the grain number per spike and dry matter assimilated after anthesis and grain yield. Under the two soil texture conditions, potassium application significantly increased the grain yield of winter wheat, and K2 treatment had the highest yield. Compared with K1 treatment, the grains number per ear, the SPAD and net photosynthetic rate of flag leaves after anthesis, the accumulation of dry matter per stem after anthesis, and the transfer of assimilation to the grain after anthesis were increased under K2 treatment. Under sandy loam conditions, grain yield of K2 treatment was by 12.4% and 10.4% higher than that of K1 treatment, respectively. Under silt loam conditions, grain yield was by 5.2% and 5.4% higher than that of K1 treatment. Those results indicated that wheat yield was significantly increased by changing potassium fertilizer base application to 50% base application with 50% topdressing at jointing stage, and the wheat yield was higher in sandy loam field.