Wheat growers on soils with reasonable levels of phosphate and potash could boost yields and profit by switching to spring dressings of those nutrients. 

Such an approach gave yield responses worth up to £60/ha in trials in Lincs last season (see table), according to Yara UK.

The work compared the impact of an autumn dressing of 60kg/ha each of P and K (as a 0:26:26 blend) followed by 60kg/ha of N, against the same amount of all three nutrients in Yara’s Universal 16 (16:16:16) in one spring application. 

All other inputs were identical. 

“Yield increases ranged up to 5%, the biggest being with Solstice,” said the firm’s head of agronomy Mark Tucker. 

With the grain valued a ‘realistic’ £130/t that gave an extra £60/ha in yield alone, he noted. 

“The true financial benefit would be even greater when taking into account reduced application costs.” 

All varieties were sown on the same day in early September which perhaps explains why Einstein, which tends prefer later sowing, yielded less well with the spring approach, added Mr Tucker. 

Spring top dressing of P and K is particularly recommended on soils above index 1 and has two key benefits, Mr Tucker explained. 

“Firstly, phosphate and potash applied over winter is at a greater risk of run off which is environmentally bad practice and wastes a significant investment. 

“Secondly, in a year when crops are so valuable, maximising output is vital.”

Fields with P and K indices of 0 and 1 will respond immediately to applications of fertiliser, he noted.