Which chemical fertilizer is used in wheat crop
Which chemical fertilizer is used in wheat crop
Method and time of application
Three main factors are to be considered when applying fertilizers to wheat. These are (i) application of correct doses of different nutrients after taking into account the requirements of the crop and soils reserve supply,
(ii) application of these nutrients at the right time, and .' (iii) adopting proper method of application.
1. Nitrogen: Application of nitrogen in split doses has become a i well established practice as urea is a highly leaching fertilizer. Two third or half of the quantity should be I applied at the time of sowing and remaining one third or half quantity should be top dressed at first irrigation in medium or heavy soils. On sandy soils, top dressing should be made in two or three instalments if heavy dose of nitrogen is to be applied. Under rainfed conditions full dose of N should be placed into the soil before sowing.
All nitrogenous fertilizers presently available in the market are equally effective for wheat under normal soil conditions. In calcareous soils (containing free lime) and in strongly alkaline soils, 10-30 % of applied nitrogen may be lost through ammonia volatilization, if urea or other ammonical fertilizers are used for top dressing. In such cases CAN (Calcium ammonium nitrate or Kisan Khad) should be preferred to urea.
2. Phosphorus and potash: For phosphatic and potassic fertilizers, placement below the seed is the best method in the moist soils. Full dose of phosphorus and potash should be applied at the time of sowing. If possible, place phosphorus and potash 3-5 cm to the side and 3-5 cm below the seed with the help of ferti-seed drill or by pora method. In case of phosphatic fertilizers, one should not be concerned only with total phosphorus but also with water soluble phosphorus content. For wheat, phosphatic fertilizers must contain at least 50 % of the total phosphorus in water soluble form and remaining phosphorus in citrate soluble form. This is relatively important in neutral and alkaline soils. For example, rock phosphate is relatively cheap but it will be of little use for the crop if applied in the neutral or alkaline soil because of its exceedingly low solubility.
In acid soils (pH less than 6), use of basic slag or rock phosphate may be more profitable than superphosphate or diammonium phosphate because cost per unit phosphorus is much less in the former than in the latter.Water soluble phosphatic fertilizers such as diammomum phosphate and super phosphate are most effective when applied in granular form, whereas citrate soluble fertilizers rock phosphate and basic slag are most effective in finely powdered form. Muriate of potash and potassium sulphate are the only potassic fertilizers presently available in the market. Both are equally good for wheat.
In addition to the major nutrients (N, P, and K), good responses to micronutrients, especially zinc have been obtained in many areas. If zinc deficiency has been observed in the locality, it is advisable to apply zinc sulphate @ 25-30 kg/ha at the time of last ploughing.
Method and time of application
Three main factors are to be considered when applying fertilizers to wheat. These are (i) application of correct doses of different nutrients after taking into account the requirements of the crop and soils reserve supply,
(ii) application of these nutrients at the right time, and .' (iii) adopting proper method of application.
1. Nitrogen: Application of nitrogen in split doses has become a i well established practice as urea is a highly leaching fertilizer. Two third or half of the quantity should be I applied at the time of sowing and remaining one third or half quantity should be top dressed at first irrigation in medium or heavy soils. On sandy soils, top dressing should be made in two or three instalments if heavy dose of nitrogen is to be applied. Under rainfed conditions full dose of N should be placed into the soil before sowing.
All nitrogenous fertilizers presently available in the market are equally effective for wheat under normal soil conditions. In calcareous soils (containing free lime) and in strongly alkaline soils, 10-30 % of applied nitrogen may be lost through ammonia volatilization, if urea or other ammonical fertilizers are used for top dressing. In such cases CAN (Calcium ammonium nitrate or Kisan Khad) should be preferred to urea.
2. Phosphorus and potash: For phosphatic and potassic fertilizers, placement below the seed is the best method in the moist soils. Full dose of phosphorus and potash should be applied at the time of sowing. If possible, place phosphorus and potash 3-5 cm to the side and 3-5 cm below the seed with the help of ferti-seed drill or by pora method. In case of phosphatic fertilizers, one should not be concerned only with total phosphorus but also with water soluble phosphorus content. For wheat, phosphatic fertilizers must contain at least 50 % of the total phosphorus in water soluble form and remaining phosphorus in citrate soluble form. This is relatively important in neutral and alkaline soils. For example, rock phosphate is relatively cheap but it will be of little use for the crop if applied in the neutral or alkaline soil because of its exceedingly low solubility.
In acid soils (pH less than 6), use of basic slag or rock phosphate may be more profitable than superphosphate or diammonium phosphate because cost per unit phosphorus is much less in the former than in the latter.Water soluble phosphatic fertilizers such as diammomum phosphate and super phosphate are most effective when applied in granular form, whereas citrate soluble fertilizers rock phosphate and basic slag are most effective in finely powdered form. Muriate of potash and potassium sulphate are the only potassic fertilizers presently available in the market. Both are equally good for wheat.
In addition to the major nutrients (N, P, and K), good responses to micronutrients, especially zinc have been obtained in many areas. If zinc deficiency has been observed in the locality, it is advisable to apply zinc sulphate @ 25-30 kg/ha at the time of last ploughing.
