Nitrogen Deficiency in Cereals Control

Symptoms

The whole plant looks pale yellowish green and stunted, with poor tillering and thin growth. Because nitrogen is mobile in the plant, yellowing starts on the older lower leaves first, often as a yellowing from the leaf tip running down the midrib in a V shape in maize, while the upper leaves stay greener. Severely deficient lower leaves dry and die early.

Damage

Nitrogen deficiency is one of the most common nutrient problems in cereals and directly cuts yield by reducing tillering, leaf area, plant size and grain filling, often causing losses of 20 to 50 percent or more in badly deficient fields. Grain protein and quality also fall. It is common in light, sandy or organic matter poor soils and where insufficient nitrogen fertiliser is applied.

Organic & cultural control

Build soil nitrogen over the long term by adding well rotted farmyard manure, compost and green manures, and by growing legumes in rotation which fix nitrogen in the soil. Incorporate crop residues properly and keep the soil rich in organic matter. These measures improve nitrogen supply steadily and reduce the amount of fertiliser needed.

Chemical control

Apply the recommended dose of nitrogen fertiliser such as urea, splitting it into a basal dose and one or two top dressings at the key growth stages like tillering and just before flowering, based on a soil test. For a quick recovery of a visibly deficient standing crop a foliar spray of two percent urea solution can be given. Always follow recommended rates, avoid over application near harvest and consult your KVK or agronomist and soil test for the correct schedule.

Always follow the product label, the recommended pre-harvest interval, and your local KVK or agronomist. Pesticide approvals change, so verify before use.

Prevention

Get the soil tested and apply nitrogen as per the recommendation for your crop and yield target, in split doses for better use efficiency. Keep adding organic matter and grow legumes in rotation. Irrigate properly so nitrogen is not lost by leaching, and apply top dressing when the soil is moist to get the best response.