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Copy link Growing Maizecrop nutrition advice
Everything you need to know about maize fertilisation, best practice, suitable products, field trials and more.
Crop nutrition advice for growing maize (Zea mays)
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Maize prefers a soil pH between 6.0 and 7.2, but it also performs well, especially under irrigated conditions, in calcareous soils with a pH of up to 8.5 typical of much of the Indian Geography where soil pH is > 6.5.
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Potassium is the nutrient that maize absorbs in the largest amount. The period of intensive uptake of this nutrient begins from the moment of appearance of the 6th leaf (BBCH 16) and continues until the full formation of the cob (BBCH 59).
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On sandy soils, there is a possibility the K might be leached out of the rooting zone.
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Good potassium nutrition in dry years improves the plants' resistance to water stress.
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Maize is a warm weather crop and therefore performs best when temperatures in the warm months range from 25 to 30ºC.
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Maize struggles when the mean summer temperature is below 19°C. The mechanism of effective binding of carbon dioxide is activated at 25°C during periods of flowering and maturation. Mean daily temperatures above 26°C can accelerate the germination processes, while temperatures below 15.5°C can decelerate them.
Nitrogen deficiency in maize
Yellowing of the leaves showing sulphur deficiency in maize
Nutrient requirements
| N | P2O5 | K2O | Mg | SO3 | Ca | |
|---|---|---|---|---|---|---|
| kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | kg/ha | |
| Average unit intake in kg/t dry grain + straw | 20-33 | 11-14 | 28-37 | 5 | 4 | 7 |
Table 1. Nutrient uptake by maize grown for grain [Grzebisz, 2007]
Dynamics of maize nutrient uptake over a season
Source: modified from Buchner and Sturm 1985 and UNIFA 2015; BBCH scale according to Hack 1993.
Role of nutrients
| Key parameter | N | P2O5 | K2O | MgO | CaO | SO3 |
|---|---|---|---|---|---|---|
| Yield | ++ | + | ++ | + | + | + |
| Number of grains in cob | + | + | ++ | + | + | + |
| Protein content | ++ | + | + | ++ | + | ++ |
| Vegetative growth | ++ | + | + | ++ | + | ++ |
Nutrient deficiencies
| Nutrient | Description | |
|---|---|---|
| Nitrogen | Leaf symptoms: younger leaves turn pale yellow or light green, uniformly throughout the leaves. Early senescence of tips and midribs. Later, V-shaped yellowing may appear on the leaves’ tips. Yellowing begins on the older lower leaves and progresses up the plant. Stalks are thin and spindly. Flowering is delayed. Low vegetative vigour. The root system becomes less prolific, slowing the uptake of other nutrients. Reduced yield due to incomplete cob-tip kernel development. |
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| Phosphorous | Phosphorus deficiency can be caused by insufficient P availability, or reduced uptake by roots due to cold, wet, or compacted soil. Leaf symptoms: Dark green leaves; dark purple/yellow chlorosis, and the purple colour may spread over the whole of the leaf. Reduced yields, delayed maturity. Slow growth rate, severe dieback. |
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| Potassium | Potassium deficiency symptoms are the result of insufficient potassium availability. Generally, this is caused by a soil imbalance between K+, Ca2+, Mg2+ and NH4+. Leaf symptoms include dark green leaves which show mainly on the lower leaves, chlorosis along the leaf margins developing to brown striping and necrosis. Older plants display browning of leaf tips and margins. The yield is reduced due to smaller, and cob-tip defective, kernels. | |
| Calcium | Leaf symptoms start on young leaves, which exhibit a light green colour, whitish spots, or streaky lesions and are often hooked back. | |
| Magnesium | Leaf symptoms always appear on older leaves. Green-yellow plants with dark yellow interveinal chlorosis, advancing to rust-brown or purple necrosis. | |
| Sulphur | Leaf symptoms present as a yellow striping pattern on the leaves. Firstly, on the newest leaves, without necrosis. Prominent interveinal chlorosis; veins are prominent over the leaves’ length. Plants display low vegetative vigour. Plants are stunted in advanced stages of sulphur deficiency. | |
| Boron | Leaf symptoms: Yellow, white or transparent necrotic spots. Stalks are stunted due to shortened internodes. The yield is significantly reduced due to smaller and defective cobs. | |
| Copper | Leaf symptoms: young leaves develop a bluish-green tint and come out spiralled from the whorl. Old leaves’ tips and edges wilt, turn white-grey and may die. There is some necrosis of older leaf edges, similar to K deficiency. Growing points suffer dieback, often preceded by shortened internodes. Stalk become soft and limp. | |
| Iron | Leaf symptoms: chlorosis of interveinal areas of young leaves from the summer flush, while veins and the midrib remain green. In severe cases, the leaves may become almost white. There is a reduction in size. | |
| Manganese | Leaf symptoms: young and medium-formed leaves become olive-green and develop uniform, white-yellow stripes in the midsection of the leaf. The stripes become necrotic with the dead tissue falling out of the leaf. Symptoms are similar to those for iron. Leaf tissue analysis is needed to confirm Mn deficiency. | |
| Zinc | Leaf symptoms: a pale yellowish-green chlorotic stripe near the lower half of the leaf, or on each side of the midrib, advancing to pale brown or grey necrosis. The symptoms are most prevalent at growth stages V2–V8. |
 Nitrogen deficiency |
 Phosphorus deficiency |
 Potassium deficiency |
 Potassium deficiency |
 Magnesium deficiency |
 Zinc deficiency |
 Sulphur deficiency |
 Sulphur deficiency |
Q&A
Here are some frequently asked questions we received from farmers regarding growing vineyards.
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Potassium is the main nutrient to help maize crops cope with periods of water stress. Potassium is important in regulating the water balance of the plants.
Magnesium is also important. Crops with the right magnesium content in the leaves cope better with periods of high temperatures during the hot summer days.
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In this case, we may need to apply extra N and Mg to the soil, and to the leaves (using a foliar application), in order to stimulate biomass production. We need to keep in mind that the export of nutrients at harvest is much higher than in grain maize, especially the removal of potassium. We thus need to plan for the extra fertilisers required for the return of nutrients across the crop rotation to maintain soil fertility.
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33.444 kg of grain per hectare! In 2017, David Hula achieved this world record in his own farm in Virginia, for which he was awarded the National Association of Corn Producers (NCGA) of the USA for that year.
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“False friends”! The purple colour on these young maize plants looks like P deficiency, but it is in fact a varietal characteristic. This purple colouring of the young plants of certain varieties takes place in response to low temperatures during plant emergence and establishment. In this case, there is no nutrient deficiency at this stage.
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For maize produced using irrigation, the amount of water is directly connected to the evaporative demand of the atmosphere. The evaporative demand is strongly related to air humidity, temperature, and wind.
The crop’s water demand will also increase as biomass increases. Check with your local crop advisor for specific help with your irrigation plan.
In all cases, the supply of water must be gradual, as the crop uses the soil water reserve. Supplying too much water at once will result in plant stress.
Satellite imagery, which is now widely available on many platforms, is a very useful tool to check irrigation uniformity and identify problematic spots.
