Research Objective
This project aimed to demonstrate, for a range of Saskatchewan environments and soils, small red lentils yield and quality responses to three rates of potassium (K) and sulphur (S) fertilizer and four combinations of these two nutrients.
The 2023 growing season was hot and dry, while 2024 was initially cool and wet but became hot and dry in July. Overall, significant treatment effects were relatively infrequent. There was a minor reduction in emergence with increasing S rates when combined with the highest rate of potassium. There were never any yield responses to K detected. Impacts on seed quality were infrequent and, if they did occur, were minor or inconsistent.
Lentils require relatively significant amounts of K and S but the risk of yield loss due to deficiencies when standard fertility plans are followed is low. Small quantities of either nutrient may be frequently applied as part of longer-term or rotation-wide nutrient management plans. K is rarely limiting in Saskatchewan soils. In general, K and S deficiencies are more likely to occur in coarser textured, low organic matter soils, and regular applications of these nutrients at low rates could help to maintain soil fertility over the long term and reduce the risk of deficiencies in future crops.