Results from a new survey of maize growers have revealed valuable cropping knowledge which can be shared to help livestock producers get more from their crop.
Nearly 100 producers, with a total of about 24,000 dairy and beef animals, took part in the survey.
It was the first to be carried out by the Maize Growers Association (MGA), British Grassland Society and forage specialist Grainseed since 2016.
The survey showed that the maize area on each farm has increased by 53% over the past five years – from an average of 43ha (107 acres) to 62ha (153 acres) in 2021.
In previous surveys, the main reason given for growing maize was to increase the energy of livestock rations, says Neil Groom of Grainseed.
This time it was crop reliability and better use of farmyard manure and slurry.
While maize area has increased, 24% of respondents reported growing less grass than they did five years ago, he says.
“There are obviously more people growing maize for anaerobic digesters (AD) and that has to be taken into account.
“But the general trend is for livestock producers to rely more on maize following some very difficult seasons for grass growth and silage-making.
Below, Jon Myhill of the MGA talks through some of the main findings and offers management tips and advice for getting more from the expanding UK maize area.
1. Prepare seed-beds well
Findings: 69% of growers say ploughing followed by cultivation is their seed-bed preparation method of choice, with only 8% using minimum tillage. More than half (52%) of growers subsoil regularly to reduce compaction.
- Free-draining, open soil structure is essential
- Ahead of a new season, check for compaction. Maize is a “lazy-rooting” crop, so any signs of compaction should be alleviated with a plough, subsoiler or even a shallow tine. On the other hand, if you do not have compaction, going in with a subsoiler may be an unnecessary pass
- Good seed-to-soil contact is crucial; however, optimum seed-bed conditions change depending on when the maize is sown, the soil type it is drilled into and the weather at the time of drilling. Many growers create a finer seed-bed than needed
- A rough seed-bed may be best early on (mid-April) in a colder season. Looser, rougher soil will warm up more quickly when temperatures do start to rise
- Later in the season, when temperatures are higher, a finer tilth will enable better moisture retention and absorption of heat units for speedier germination
- Before drilling, make sure you know where the moisture is in the soil. The last thing you want to do is drill into some moist areas and some dry ones, as this will lead to staggered germination and uneven crops at harvest time.
2. Optimise the use of farmyard manure (FYM) and slurry
Findings: 52% of growers say better use of FYM/slurry is the biggest advantage of maize.
- Organic manure is particularly useful for maize. It is a hungry crop and needs lots of good nutrition – specifically, potash and fresh phosphate to kickstart germination
- If using cattle FYM or slurry, an analysis is vital to know exactly what nutrients you are – or are not – applying
- A soil analysis is important, too, to understand your soil indexes
- As well as the crop, organic manure can also benefit soil structure and moisture retention
- For best results, manures should be incorporated into the soil within 24 hours of application to minimise losses
- MGA nitrogen curve trials have shown while the N max level in maize is 150kg/ha, similar yields are possible using rates of 75-100kg/ha if there was a historic use of organic manure, or if maize was grown following a cover crop
- With artificial fertiliser prices high this season, be realistic about your expected yield potential. If you historically achieve low yields, full nitrogen rates are probably not necessary
- There is also a lower carbon footprint where fewer artificial sources are used.
3. Use starter fertiliser wisely
Findings: 67% of growers always use a starter fertiliser, with a further 7% saying they use one sometimes.
- Most maize crops will benefit from a small amount of starter fertiliser at the point of drilling to aid effective germination
- Be aware of the soil index before applying. Remember, if your phosphorus index is 4 or more, you cannot apply any more phosphate to that field
- Biostimulants can aid phosphate release. While MGA trials have not specifically shown a yield benefit where biostimulants are used, we have seen an improvement in metabolisable energy (ME) and starch content of the crop.
4. Consider starting crops under film
Findings: The number of farmers growing maize under film increased to 12% in 2021 – compared with 6% in 2016.
- Growing under film creates more heat units for the plants and provides a microclimate to enable successful germination
- This expands the geographical potential for maize, meaning growers in non-traditional areas, such as the North, can get good results from the crop
- To justify the additional cost, it is important to get a good seed-bed, as the film has to be buried in the soil at the edges of each row
- Best results will also come from selecting varieties that are suited to being grown under film
- Starch-based films with no plastic content are being developed amid environmental concerns.
5. Mitigate against summer droughts
Findings: Out of the 52% of growers saying climate change is a key management issue, 62% said summer droughts are their biggest problem.
- Met Office weather data analysis over the past five years has trended towards warmer, wetter winters, combined with extended summer droughts
- On droughty soils is it worth keeping seed rates down to 85,000-95,000 seeds/ha
- Use of FYM and slurry, as well as good cultivations and rolling immediately after drilling, will help conserve soil moisture. If you are on drought-prone land, consider applying more FYM/slurry
- If you are in an area that traditionally has low rainfall, opt for varieties that have proven higher levels of drought tolerance
- Yields can be higher where maize is irrigated, but this can be costly.
6. Make better use of cover crops
Findings: Growing cover crops is a post-harvest management practice for 28% of farmers.
- Cover crops are valuable from an environmental perspective, but also help to condition the soil ahead of maize
- Depending on the mix of species used, following crops can also benefit from higher nitrogen availability and other key nutrients
- Cover crops offer an additional source of income via outwintering cattle or sheep
- A three-way mix including nitrogen-fixing species such as vetch or clover works well for maize. Alongside that, it is important to have good ground cover, provided by oats or rye, for example. Phacelia and radish are also useful additions
- Cover crops should be drilled as early as possible to avoid soil moisture losses after combining.