Main Objectives
Nitrogen application technologies that minimise losses and maximise N uptake have been linked to improved fresh weight and sugar yields, Stevens at al (1995). These authors attributed this in part to earlier canopy establishment and improved nitrogen use efficiency. Work by the Nordic Beet Research (NBR) Institute has also indicated small but consistent responses in terms of crop yield and sugar content to the use of placed nitrogen and phosphate fertiliser. The table below shows the range of relative yield increases due to N placement across a series of NBR trials between 1979 & 1994.
|
1979 |
1980 |
1981 |
1982 |
1988 |
1989 |
1990 |
1991 |
1992 |
1993 |
1994 |
|
|
|
|
|
|
|
|
|
|
|
|
|
101% |
102% |
102% |
103% |
106% |
105% |
103% |
102% |
108% |
108% |
105% |
In the USA, the use of placed N fertilisers and placed phosphate as a starter fertiliser to encourage early plant establishment is widely recommended by advisors and practiced by growers. Pilot work has been undertaken in plot work at Nottingham University and commercial farms trials in Norfolk 2016. Interestingly, this work showed some improvement in early season canopy development but the effects diminished over time and by final harvest there were no significant effects on yield. At the commercial site, turkey manure and a cover crops was used prior to the beet and the higher soil N levels may have reduced the impact of placed fertilisers. At the experimental site at Nottingham, plots were affected by Aphanomyces and it not clear to what extent this may have affected results.
However, the published data indicates placement of N fertiliser and the use of starter P is worthy of further investigation. For the UK, it will be important to understand in more detail the interaction between fertiliser placement, soil texture, soil mineral N content and emergence, canopy expansion to assess in what circumstances yield benefit is seen as well as opportunities for improved N use efficiency and reduced N inputs.
It is proposed to build extend the work started in 2016 to more sites over a further two years, allowing us to make a full assessment of both the efficiency of nutrient utilisation and the practical and financial aspects of fertiliser placement. This will provide a total of 3 years of data (including 2016 trials) on which to base informed advice to growers. It will also support any specific recommendations in the next planned edition of RB209 (The Nutrient Management Guide) in 2019.
Latest Report
Outcomes / Key Message For Growers And Industry
- There were no significant effects of different fertiliser regimes on sugar yield. Plots receiving 60Kg yielded the same as plots receiving 120kg/ha. The effects of phosphate was not tested in 2017 but will be tested in subsequent seasons.
- The absence of responses is likely due to the very favourable weather conditions in 2017. Post germination temperatures and rainfall facilitated very rapid plant growth. Plants reached full crop cover very rapidly with no differences in canopy growth between treatments. The warm temperature and moist soils would have also encouraged elevated levels of soil mineralisation of nitrogen throughout the growth period, reducing reliance on applied nitrogen and masking differences between treatments. Differences between these treatments are likely to be more pronounced in a challenging season, especially in the period between emergence and establishment (6-leaf stage).
- This represents the first year of data and over the next few years, as this data set begins to build, we will have a better understanding of how different nitrogen application techniques can be best used to enhance yields.
