The effect of method and rate of application of common salt and muriate of potash on sugar beet

Abstract

SummaryTwelve experiments in the East of Scotland tested a hypothesis that the smaller yield responses to salt in Scotland than in England shown by previous work was due to the adverse effects of soluble salt concentration brought about by ridging, and also to test a wider range of salt and potash than used previously. All combinations of three rates of salt (0, 315, 630 kg/ha) and three rates of muriate of potash (0, 315, 630 kg/ha) were applied in four ways: (1) ploughed down in winter, (2) on the furrow in February, (3) in the seed bed and (4) half as (1) and half as (3). Plant emergence was decreased by salt and potash in only three experiments and then only when the larger amounts of both fertilizers together, along with nitrogen and superphosphate, were applied in the seed bed prior to ridging. Both experiments were in a year when the weather was dry while the plants emerged. Yield of sugar was greatest with the February application on the furrow and smallest with the ploughing down method. At equal weights, salt and muriate of potash had similar effects on sugar yield. Equations derived from the response surface gave the most profitable dressing as 377 kg/ha of salt plus 127 kg/ha of K2O which gave a £4.90 greater margin per hectare over costs than the best potassium application without salt.