Since lentil is harvested close to the ground, smooth soil surfaces and stone-free conditions are desirable. A land roller can be used between seeding and the fifth node stage (no later) to level fields and push down stones. Be mindful of crop staging; rolling after the fifth node stage can damage stems and branches and can seriously reduce yields. Water ballast is not needed, since packing is not the goal of this operation.
Do not roll:
- before emergence if soil is excessively wet and/or prone to crusting.
- after emergence if a frost has just occurred, which may cause crop damage and yield loss due to increased crop stress
- when plants are damp from rain or dew – in these conditions, plant leaves adhere to the roller and tear, spreading diseases like ascochyta
To avoid possible yield reductions and crop damage due to stress, leave at least a two-day break between rolling and herbicide applications. Herbicide application is the recommended first operation if a choice has to be made between the two. The damage to yield by weed competition will be more severe than losses associated with a crop that has not been rolled.
N starvation may occur during and immediately following emergence. Lentil plants begin root nodule formation about two weeks after plant emergence. During this period, plants may turn pale green, called the “period of N starvation,” and it is normal. With proper inoculation, nodules will soon start to function and eliminate this problem.
- check the nodulation process by digging individual plants approximately four weeks after emergence – root surfaces and especially areas of the crown should display small swellings, which are the nodules
- if no nodules are visible at four weeks after emergence, plants should be re-sampled in another week or two. If nodulation failure is occurring, a nitrogen application may be advisable to preserve yield potential
- yellowing of a lentil crop may also be due to flooding, which deprives roots of needed oxygen (these conditions, if they persist, will also cause inoculant failure). Yellowing may also be a condition of seedling root rot
- soils with high N content prior to planting will inhibit nodule formation and are unsuitable for lentil production
- sample plant root systems at early flowering (nodule presence and color are the important factors):
- at flowering, each lentil plant should have several elliptical shaped nodules on its root system
- these nodules will appear in clusters and should be pink – the pink colour indicates that the nodules are active
- the proper number of nodules may be difficult to determine because nodules adjust their size and activity level in relation to their number
Lentil Irrigation & Water Use
Eston, a determinate type, is better suited for production under irrigation. This type does not display the delayed maturity, increased disease and lower yields normally associated with high moisture. Even with Eston, however, excess water can cause problems.
Irrigated lentil production requires careful management because lentil dies quickly when flooded.
Irrigation research in Alberta has shown that Eston yields are highest when plants use 8 to 14 in. (20 to 36 cm) of water. Although lentil uses water efficiently, it is a shallow-rooted plant and therefore needs significant soil moisture to produce optimum yields.
- when irrigating, don’t let water accumulate on the soil surface, especially at seeding time
- apply 0.8 to 1.2 in. (2 to 3 cm) of water in early June to prevent plant stunting and yield reduction, especially if plants are starting to display drought symptoms
- if metribuzen (Sencor® or Lexone®) is applied to the crop, delay irrigation for at least two weeks after spraying – this will prevent leaching of the herbicide into the lentil rooting zone, which could result in crop damage
- irrigation is usually discontinued when flowering begins – moisture stress at this time is desirable and will promote flowering
- approximately 4 in. (10 cm) of water is recommended after the stress period – this will encourage pod formation and filling.
- after this time, irrigation should be discontinued – moisture stress on the crop will be needed to enhance crop maturity