Nutrient deficiency / toxicity symptoms

• Nitrogen deficiency: Plants become stunted and yellow in appearance first on lower leaves. In case of severe deficiency the leaves will turn brown and die. Deficiency symptoms first appear at the leaf-tip and progress along the midrib until the entire leaf is dead.

• Potassium deficiency: Bluish green leaves - when young, older leaves irregular. Chlorotic and necrotic areas - grain formation is poor - weakening of the straw which results in lodging.

• Magnesium deficiency: Leaves are chlorotic with white tips.

• Iron toxicity: Brown spots on the lower leaves starting from tips and proceeding to the leaf base and turns into green or orange purple leaves and spreading to the next above leaves.

• Zinc deficiency: Lower leaves have chlorotic particularly towards the base. Deficient plants give a brown rusty appearance.

• Copper deficiency: Leaves develop chlorotic streaks on either side of the midrib and appearance of dark brown necrotic lesions on leaf tips. Unfolding of the new leaves will also be seen.

Neem treated urea and coal-tar treated urea

• Blend the urea with crushed neem seed or neem cake 20% by weight. Powder neem cake to pass through 2mm sieve before mixing with urea. Keep it overnight before use (or) urea can be mixed with gypsum in 1:3 ratios, or urea can be mixed with gypsum and neem cake at 5:4:1 ratio to increase the nitrogen use efficiency.  For treating 100 kg urea, take one kg coal-tar and 1.5 litres of kerosene. Melt coal-tar over a low flame and dissolve it in kerosene. Mix urea with the solution thoroughly in a plastic container, using a stick.  Allow it to dry in shade on a polythene sheet. This can be stored for a month and applied basally.

Application of P fertilizer

• P may be applied as basal and incorporated.

• When the green manure is applied, rock phosphate can be used as a cheap source of P fertilizer. If rock phosphate is applied, the succeeding rice crop need not be supplied with  P. Application of rock phosphate + single super phosphate or DAP mixed in different proportions (75:25 or 50:50) is equally effective as SSP or DAP alone.

Application of zinc sulphate

• Apply 25 kg of zinc sulphate mixed with 50 kg dry sand just before transplanting.

• It is enough to apply 12.5 kg zinc sulphate /ha, if green manure (6.25 t/ha) or enriched FYM, is applied.

• If deficiency symptom appears, foliar application of 0.5% Zinc sulphate + 1.0% urea can be given at 15 days interval until the Zn deficiency symptoms disappear.

Application of gypsum

• Apply 500 kg of gypsum/ha (as source of Ca and S nutrients) at last ploughing.