The Ultimate guide to Forage Maize

An introduction to Forage Maize

·         Maize silage is a cost effective, high energy and starch rich forage

·         Can be used to complement high protein forages, such as grass silage

·         Feeding two forages stimulates appetite, which in turn increases milk yield

·         Should reach 30% DM to ensure efficient production of milk, beef or biogas

·         Relatively low production costs

·         Single cut harvest

·         High DM

·         Slowly degradable starch

·         Beneficial effect on the rumen stability

·         Extra energy

·         Variety choice to suit requirements


2018 season review

·         Very wet and prolonged winter, with low soil temperatures.

·         Soils were wet making poor cultivation conditions

·         With the improvement in weather, soils quickly warmed up and crops managed to get away quickly

·         The weather soon turned conditions more difficult, with plants showing signs of drought stress

·         Early sown crops seemed to fair better than later drilled, which suffered in the dry soils and heat. The earlier drilled crops had more leaf cover which helped to conserve moisture

·         Plants that had poor rooting couldn’t stand up to the storms that came later in the season, this affected large plants with poor root structures

Drilling Tips & Considerations


Avoid high altitude sites which are often colder. As a rule, growers should consider 600 feet above sea level to be very marginal and have a shorter growing season. However, individual fields above 600 feet with lighter, drier soil types that will warm up quickly in spring can be considered.


Ideally any fields selected for maize production should face south and be sheltered from wind. Avoid fields which are very exposed, or have heavy, poorly drained soils, and any locations which are known to suffer from frost. An established crop at 2-6 leaf stage can be set back 2-3 weeks by a late May frost. Avoid steep sloping fields to reduce the risk of nitrate leaching and soil erosion.

Soil Depth

To support its bulk and height, a maize plant requires a very extensive root system. Ideally, crops should be grown where there is a good depth of topsoil. Where the soil is shallower, root development may be impaired and produce stunted crops, with resultant lower yields. Crop maturity can also be delayed. The same effects can occur where soil is compacted. Seed should be sown on to a firm base at 3-6cm depth. Use deeper sowing for lighter, drier soils and shallower sowing for heavy sols. Despite this, drilling into moisture is more important than depth.

Weed Control

Maize can suffer considerably from weed competition during the early growth stages. Ideally, a clean, weed-free site should be chosen. A weed control programme applying either pre-emergence and/or post emergence herbicides can be followed. Fitting in with the rotation Maize can be continually grown on the same ground, if the soil pH and nutrient levels are maintained. Early maturing varieties that are harvested in September can have a wheat or grass crop as a follow on. Maize can also serve as a break crop for cereals. Environmental Considerations Harvesting maize in wet conditions can lead to surface compaction. Maize stubble left uncultivated over the winter months can result in surface water runoff and nitrate leaching into waterways. There is also a particularly high risk of soil erosion where fields are sloping and have sandy soil. If your fields are of a higher risk, then consider growing an early maturing variety aiming for an early harvest. In better weather, a light cultivation after harvest will encourage rainfall ingression and reduce run off, or establishing a cover crop to stabilise the soil surface may be a good option.

Maize Agronomy



Broad leaved weeds and grass weeds – PDM (Anthem)

Post-emergence (before buttress roots develop)

Broad leaved weeds – mesotrione (Callisto)

Thistles – clopyralid (Dow Shield)

Docks and volunteer potatoes – fluroxypyr (Hurler)

Grass weeds – nicosulfuron (Fornet)


Eyespot – pyraclostrobin (Comet 200)

Soil Analysis

As maize is a valuable crop with a high demand for nutrients it is important to know the soil pH and available nutrient levels in order to apply the necessary lime and fertiliser to ensure good crops. Maize needs an optimal pH of 6.8. The field should be limed if the pH is 6.0 or lower.  In addition to variety selection, being successful in growing maize is also dependent on following good agronomy and management practices. Optimal soil conditions at drilling are required to ensure good germination and plant establishment. Modern maize hybrids have a high degree of cold tolerance but should not be drilled before soils have reached an even temperature of 8°C for light soils, 10°C for heavy soils for 3-4 days, usually around mid-April to May.

Soil Nutrient Requirements

To produce a good crop, maize plants need to grow very rapidly once they have germinated. They will do this providing the soil moisture and structure are good; the temperature is warm, and nutrition is adequate. Maize can easily produce 50t/ha of fresh weight in a period of four months. To support this rapid growth, it has a large demand for nutrients and any shortage will restrict early growth and final yield. Although established crops have a well-developed root system, root growth is slow in the early days of the crop, especially if the weather is cold. Poor root growth means decreased uptake of nutrients and this can be a vicious circle as poor uptake of N and P can restrict root growth. For this reason, it is advised that a starter fertiliser is placed close to the seed, even when the bulk of the soil is adequately supplied with nutrients. If you are looking at fields that traditionally suffer from run-off or are prone to erosion, then consider a slightly earlier maize variety (modern genetics often mean that you won’t lose yield and often gain some quality) and look to place a cover crop in to help scavenge nutrients and stabilise surface soils. This in turn can be used as a green manure, used for grazing or potentially harvested before the following crop. Maize is a very convenient crop on which to apply manure in the spring when there are limited opportunities for spreading on grassland. Be careful that applications do not exceed 250 kg/ha of total nitrogen to conform to the Code of Good Agricultural Practice and NVZ requirements. As maize is a valuable crop with a high demand for nutrients it is important to know the soil pH and available nutrient levels in order to apply the necessary lime and fertiliser to ensure good crops. When the maize field has been chosen a soil sample should be taken for analysis unless the field has been tested within the last 3-5 years. Bartholomew’s provide a complete soil analysis package which allows a tailored approach to nutrient management.

Fertiliser Requirements for Forage Maize


Option One: No Organic Manures


Option Two: 40 t/ha of Organic Manure


It is essential to take crop nutrition seriously when it comes to forage maize in order to optimise the yield. To do this it is important to know your soils.

• Based on soil analysis, we are able to offer nutrient advice and produce a nutrient plan.

• Bartholomews are able to supply a full range of fertiliser products, from straights to blends, mixed to your requirements.

We have formulated products specifically for maize and offer a comprehensive range.


Starter Fertiliser

To be applied, where possible, down the spout and placed near the seed in order to get the maize off to the best start.

• Bartholomew’s maize START UP (14N  35P +5MgO + 10SO3)

• DAP (18 N  46P)

• TSP (46P)


Main Fertiliser

To be applied in the seedbed and worked in just prior to drilling. Alternatively, it can be applied after drilling depending on practicalities and preference.

• Bartholomew’s Maize FIX - ONE (10N  3P  28K + 5MgO + 8SO3)

• Bartholomew’s Maize FIX - TWO (14N  0P  24K + 3MgO +11SO₃)

• Bartholomew’s Maize FIX – THREE (5N  12P  34K + 4MgO + 8SO₃)


Final Fertiliser

To be applied, if needed, as a top dressing after weed control (no later than 3 leaf stage)

• Nitram (34.5N)

• 27N – 9SO₃

 Please remember to observe all the relevant Cross Compliance guidelines that are now applicable.

There are a number of different things to consider when planning nutrient applications to Maize. On the next page there is a step by step guide which can be followed to achieve accurate understanding of what your crop needs and how to achieve its requirements.

Remember: This is only a guide and requirements and nutrient values may differ depending on specific situations.

*NPK requirements derived   from RB209. MgO & SO₃ requirements adapted from industry recommendations in RB209 (Fertiliser Manual) & PDA booklet (Potash Development Association).



Options after Maize

• Follow maize with Wheat

• Forage rye • Westerwolds


• Cover crop (EFA sown by Oct 1st)

• Stubble turnips/forage rape up until mid-September

• Possibility of under sowing – IRG or Cocksfoot

If you have any queries at all regarding growing forage maize, please don’t hesitate to get in touch with our team on 01243 784171 or email