Nutrient and irrigation management

Abstract

Lentils are often grown in difficult edaphic conditions on stored soil water. This usually results in low yields. While water stress is often responsible for these low yields, low levels of soil fertility can also be a contributing factor. Lentils can usually fix enough N for their own requirements, although if sown into soil with extremely low available N or into cold, wet soil they may require a small amount of starter N to ensure adequate early growth to support nodulation and N fixation. While responses to fertilisers are variable, there are many reports that P at 40-60 kg/ha can help provide increased yields. Also, application of K at around 20 kg/ha may be beneficial in sandy or eroded soils. Sulfur is unlikely to be deficient if fertilisers containing S impurities are applied to other crops in the rotation. Of the micronutrients Zn and B are the two most likely to be deficient.While breeding and management can reduce the effects of drought stress lentils will often respond to irrigation with substantial yield increases. However, their high sensitivity to water logging means that irrigation can be overdone and thus decrease yield. Irrigation requirements are best calculated by considering the limiting water use deficit of the crop and irrigating to control soil moisture deficit to a value suited to the variety and soil type