know your fertilizers before you use them; Attributes and determination of Fertilizers

June 15, 2020May 4, 2023 Agrovista 3 Comments

know your fertilizers before you use; Attributes and determination of Fertilizers

Fertilizers differ from one another in nutrient content, a form of the nutrient, water-solubility, mobility, etc. Nitrogen and potassic fertilizers have much higher salt indices than phosphatic fertilizers and hence detrimental to germination when placed in contact with the seeds. Phosphatic fertilizers have greater efficiency especially containing much water-soluble phosphorus than citrate soluble.

How to Increase the efficiency of fertilizer ;

The time of application also plays an important role in using fertilizer efficiency. Nitrogenous fertilizers being mobile has greater chances to escape, whereas phosphorus and potassic fertilizers are less movable. The crops are grown in the rainy season be given in split doses so that loss is minimized. The foliar application has been found very beneficial. Slow-release fertilizers are being popular and suitable in Indian conditions.

How to make fertilizer Selection;

The fertilizers are selected on the basis of the following recommendations.

A) How to Select Nitrogenous Fertilizers for Crop

Table of Contents

Application

1)In paddy ammonium fertilizers viz. ammonium sulphate, ammonium chloride and Urea should be used, Calcium ammonium nitrate, diammonium phosphate may also be applied
2) In acid soils or calcium deficient soils, continuous application of ammonium sulphate, urea, ammonium chloride and ammonium sulphate nitrate should be avoided or lime is given before fertilizer application.
3) In winter or rabi season all nitrogenous fertilizers are equally effective, therefore the fertilizers should be selected on the basis of cost, availability, and easier of application.
4) For top dressing, sodium nitrate and urea are the best suitable fertilizers.
5) In sandy soil or well-aerated soils, split doses of nitrate fertilizers are given. The application of sodium nitrate in the rainy season is avoided.

B) How to Select Phosphate Fertilizers for Crop
Application

1) Acidic soils are most suitable for the application of rock phosphate and basic slag.

2) Superphosphates contain water-soluble phosphates, thus the nutrient in these fertilizers is available to plants even in the young stage when it required most. Superphosphates should be applied just before sowing, as phosphorus requirement in the early stage of plant growth is high.
The entire recommended dose of superphosphate shall be applied before sowing of paddy, wheat, jowar, cabbage, cauliflower, potatoes etc. In long-duration crops like sugarcane, the second split dose may be given with the first earthing up.
3) Superphosphates should be used in neutral to alkaline soils but not in acidic soils. In acidic soil, the water-soluble phosphorus changes to insoluble iron and aluminum phosphates, hence it is unsuitable in acidic soils.
4) Basic slag, dicalcium phosphate, bone meal are particularly suitable for acidic soils as low pH converts citrate soluble phosphoric acid to water-soluble monocalcium phosphate.
5) Phosphatic fertilizers like ammonium phosphate, nitro phosphate, monocalcium phosphate, dicalcium phosphate, Rhenamia phosphate, and Kota phosphate have available phosphorus and can be applied in any crop to be grown in neutral soil.
5) Phosphatic fertilizers should be placed near the root zone or in the soil layer, where the roots are most active as phosphates are least mobile. (vii) In fruit trees like citrus, guava, apple, etc. it should be placed deep with a deep cultivator.

B) How to Select Potassic Fertilizers for Crop Application

Muriate of potash is suitable for all crops. It can be applied any time but the early stages of the crop require this nutrient the most. Hence it is applied before sowing It is soluble and mobile.

On application to soil, it dissociates to Kions and gets attached or adsorbed on the soil complex. As such this fertilizer, though soluble in water, is not easily lost by leaching.