Building Yield – the type of ‘N’ matters
It was not so long ago we were wishing it would stop raining, now we find ourselves wishing it would rain [again] to help spring crops germinate and wash in spring applied fertiliser! The recent warm dry weather has in quite a few cases turned wet sodden soils into what resembles cracked slabs of concrete in which poorly rooted crops may be at risk of drought conditions later on if rain does not materialise during stem extension (the construction phase).
The construction phase of growth is the period during which ‘both’ canopy expansion and root growth occur at their most rapid rate and it is therefore no surprise that this also coincides with when the bulk of nitrogen fertiliser is applied to the crop. Nitrogen (N) is what largely drives green canopy expansion, with the majority of the N taken up as nitrate-N. However, if robust canopy growth is not balanced with strong root growth [to provide the canopy with adequate moisture and essential nutrients], large crop canopies may only serve to waste resources that could have been used for yield.
Robust crop canopies (supported by strong lateral roots) are more sustainable into the ‘production phase’ of growth, maintaining Green Leaf Area (GLA) when solar radiation is at its strongest maximising the use of light energy [via photosynthesis] for crop yield. As already stated, strong rooting is very important to support strong/sustainable canopy growth and whilst nitrate-N does promote root growth, this growth is generally straight down, however, most of the essential nutrients a crop requires are in the top 30cm of soil. So whilst deep rooting is important [for moisture] it is also important that plants can source the essential nutrients they require (such as phosphorus) from the top layer of the soil to support growth and ultimately yield. Feeding plants on a mixed source of nitrate-N and amine-N will encourage more lateral root proliferation enabling plants to better source nutrients they require from the soil. In addition, the enhanced rooting will also be of benefit to crop anchorage [in a year when many crops may be compromised!] via the promotion of crown roots that aid plant anchorage and therefore help reduce root lodging.
‘LimiN Technology’ within the Elona crop range stabilises nitrogen in the amine form (SAN) supporting robust canopy growth by promoting strong lateral rooting. Research carried out by Dr Sally Wilkinson (2020) by exposing winter wheat plants to bursts (foliar applications) of Elona containing ‘LimiN Technology’ demonstrates how rooting is promoted over the control and an industry standard product (figure 1), whilst also promoting thicker tiller diameter (figure 2) and chlorophyll leaf index (figure 3), helping to support improved crop architecture, standing ability and photosynthetic potential.
Figure 1. Comparison between the effects of SAN (Elona), control and industry standard (IS) foliar N fertilisation treatments on root length.
Figure 2. Comparison between effects of SAN (Elona), control and industry standard (IS) foliar N fertilisation treatments and tiller diameter.
Figure 3. Effect of foliar SAN (Elona) application on leaf chlorophyll content of wheat plants 7 days after treatment, compared to conventionally fertilized control and industry standard (IS) treated plants.
The crops we see in front of us in 2020 are in many cases atypical due to the autumn and winter that has gone before. Typical growth stages around which normal T0 and T1 fungicide timings would normally be planned are in many cases merging, with T0 not happening, leaving only a well-timed T1 to address disease issues. With this being the case it also means that other important management interventions may not take place [such as PGR application to aid rooting or application of essential plant micronutrients] that would have otherwise occurred alongside the T0 fungicide. This will make the next spray timing all the more important to address potential crop issues.
When considering crop rooting it is important to understand that varietal influence is quite low [most likely due to varietal screening having not selected for this trait], with the biggest influence on rooting coming from date of sowing [which in most cases was compromised due to late drilling], field drainage and soil structure [again compromised in many cases due to conditions last autumn/winter]. With this in mind the use of ‘LimiN Technology’ found within the Elona crop range from levity Crop Science is worth considering to aid robust crop growth helping to maximise crop yields in a less than ideal year!
(121g/l N, 22g/l MgO, 80g/l Mn, 5g/l Zn, 1.3g/l Cu) – May be applied at 1.5-3l/ha with repeat applications as required.
(180g/l N, 84g/l K2O) – May be applied at 2-4l/ha with repeat applications as required.
(135g/l N, 150g/l MgO, 15g/l Zn) – May be applied at 2-4l/ha with repeat applications as required.