Chemical Fertilizers as a Component of Integrated Nutrient Management

1. Chemical Fertilizers as a Component of Integrated Nutrient Management Next

2. Chemical Fertilizers as a Component of Integrated Nutrient Management Introduction Fertilizer can be defined as a mined, refined or manufactured product containing one or more essential plant nutrients in available or potentially available forms and in commercially valuable amounts without carrying any harmful substance above permissible limits. Many prefixes such as synthetic, mineral, inorganic, artificial or chemical are often used to describe fertilizers and these are used interchangeably. End Previous Next

3. Chemical Fertilizers as a Component of Integrated Nutrient Management Introduction Fertilizers have been traditionally classified into following two group, depending upon the number of nutrients available in them. Straight fertilizers Complex/ compound fertilizers End Previous Next

4. Chemical Fertilizers as a Component of Integrated Nutrient Management • Straight fertilizers Straight fertilizers contain one of the three major nutrients N, P or K. This is a traditional term referring to fertilizers that contain and are used for one major nutrient as opposed to multinutrient fertilizers. For secondary nutrients, these include products containing elemental S, magnesium sulphate, calcium oxide, etc. In the case of micronutrients, borax, Zn and Fe chelates and sulphate salts of micronutrients are straight fertilizers. However, the term is not often used for micronutrient carriers. End Previous Next

5. Chemical Fertilizers as a Component of Integrated Nutrient Management • Complex/compound fertilizers Complex or compound fertilizers contain at least two out of the three major nutrients. They are produced by a chemical reaction between the raw materials containing the desired nutrients and they are generally solid granulated products. These include both two-nutrient (NP) and three nutrient (NPK) fertilizers. End Previous Next

6. Chemical Fertilizers as a Component of Integrated Nutrient Management • Complex/compound fertilizers These are also referred to as multinutrient fertilizers, but do not include fertilizer mixture or bulk blends as no chemical reaction is involved. • Multinutrientfertilizers can be further classified into: Complex/compound fertilizers; Mixtures and bulk blends; Multimicronutrient carriers; Fortified fertilizers. End Previous Next

7. Chemical Fertilizers as a Component of Integrated Nutrient Management Mixed Fertilizers Mixed fertilizers are advantageous because they reduce cost of application and ensure better mixing in soils. These fertilizers can be used on all crops grown under different conditions of climate, soil and crop husbandry. Their use has been advantageous and is the effective way to supply the fertilizer requirements of a crop. End Previous Next

8. Chemical Fertilizers as a Component of Integrated Nutrient Management Importance of Mixed Fertilizers Application of mixed fertilizers save labour cost. Granulated mixed fertilizers are good source because many nutrients can be applied at a time. Nutrients are distributed evenly in the crop root zone Fertilizer use efficiency is increased Mixtures prepared by farmers are cheaper than purchased from the market. The firm and free flowing granules are safe for spreading by hand. Mixed fertilizers are also well suited for application by machine. End Previous Next

9. Chemical Fertilizers as a Component of Integrated Nutrient Management Neem Coated Urea Urea is most widely used fertilizer of nitrogen & is produced by reacting ammonia with carbon dioxide under pressure and high temperature. Urea is placed in reduced zone in submerged soil to minimize volatilization and denitrification losses. To facilitate deeper placement, urea is manufactured as super granules and made into bolls. To reduce nitrification losses, ordinary prilled urea is coated with neem oil. At present, it is being manufactured by the leading fertilizer manufacturers in the country. End Previous Next

10. Chemical Fertilizers as a Component of Integrated Nutrient Management Neem Coated Urea Good paddy crop due to neem coated urea End Previous Next

11. Chemical Fertilizers as a Component of Integrated Nutrient Management • Advantages of neem coated urea Slow release of nitrogen by extending the urea hydrolysis for a longer period. Inhibits nitrification. Reduces nitrogen losses by leaching and dentrification. Increased nitrogen use efficiency in paddy. Regulates supply of nitrogen coinciding with the crop growth and development. Increases growth and grain yield of paddy End Previous Next

12. Chemical Fertilizers as a Component of Integrated Nutrient Management Mode of Application Application of recommended dose of fertilizers in two or three splits during crop period is known as split application of fertilizers. The number of split application has to be more in light soils and less in heavy soils. Nitrogen is applied in more splits for long duration crops. The stage of application is also important. In cereals, nitrogen is applied at tillering and panicle initiation stages in addition to basal application. End Previous Next

13. Chemical Fertilizers as a Component of Integrated Nutrient Management Time of Application Nitrogenous fertilizers are generally recommended to be applied in splits, depending upon climate, soil and crops. Application of phosphatic and potassic fertilizers to field crops is recommended as basal. In a Phosphorus deficient field, a delayed application is better than no application at all. In tree crops, giving all phosphorus and potassium only once as basal is not a practical preposition because of their long life. End Previous Next

14. Chemical Fertilizers as a Component of Integrated Nutrient Management Methods of Fertilizer Application Soil Application / Broadcasting Application of fertilizer uniformly on the soil surface is known as broadcasting of fertilizers. This is done either before sowing of the crop or in the standing crop. Broadcasting is the most widely practiced method in India due to ease in application. Broadcasting is advantageous with solid and soluble fertilizers. End Previous Next

15. Chemical Fertilizers as a Component of Integrated Nutrient Management Methods of Fertilizer Application Broadcasting is The entire dose of phosphatic and potassium fertilizers are applied by broadcasting before sowing. Because of their low mobility in soil, these fertilizers are incorporated into the rooting zone. Broadcasting of Fertilizer End Previous Next

16. Chemical Fertilizers as a Component of Integrated Nutrient Management Row or Band Placement When localized fertilizer placement (putting the fertilizer only in selected places in the field) is used, the fertilizer is concentrated in specified parts of the soil during planting, which may be either in bands or strips under the surface of the soil or to the side of, and below, the seed. This can be done either by hand or by special planting and/or fertilizer drilling equipment (seed-cum-fertilizer drill). It is preferably used for row crops, which have relatively large spaces between rows (maize, cotton, and sugar cane); or on soils with a tendency to phosphate and potassium fixation; or where relatively small amounts of fertilizer are used on soils with a low fertility level End Previous Next

17. Chemical Fertilizers as a Component of Integrated Nutrient Management Side-dressing Applying fertilizer as side-dressing is the practice of putting it to the side of widely spaced plants grown in rows such as maize, cotton and sugar cane. Trees or other perennial crops also are normally side-dressed. http://www.ytmag.com/cgi-bin/viewit.cgi?bd=ttalk&th=985229 End Previous Next

18. Chemical Fertilizers as a Component of Integrated Nutrient Management Foliar application Foliar application is the most efficient method of supplying micronutrients (but under a stress situation for the crop also N or NPK) which are needed only in small quantities and may become unavailable if applied to the soil. To minimize the risk of leaf scorch, the recommended concentration has to be respected and spraying should preferably be done on cloudy days and in the early morning or late afternoon (to avoid an immediate drying of the droplets). www.plantmanagementnetwork.org/.../2005/boron/ End Previous Next

19. Chemical Fertilizers as a Component of Integrated Nutrient Management Determining fertilizer needs To determine fertilizer needs for crops and soils, knowledge of the following two things is essential: Which nutrients are needed in the fertilizer? How much of each nutrient is needed to get the highest or most profitable (optimum) yield? There are several approaches to finding the answers to these questions. It includes: Nutrient hunger signs on growing crops (deficiency symptoms). Soils tests or analyses to determine the fertilizer nutrients and amounts needed. Plant and/or plant tissue tests in the field. Fertilizer field trials End Previous Next

20. Chemical Fertilizers as a Component of Integrated Nutrient Management Different methods of fertilizer application End Previous Next

21. Chemical Fertilizers as a Component of Integrated Nutrient Management Let us sum up The combination of organic manures and chemical fertilizers (Integrated Plant Nutrition Management, IPNM) provides the ideal environmental conditions for the crop, as the organic manure/organic matter improves soil properties and mineral fertilizers supply the plant nutrients needed. However, organic manure/organic matter alone is not sufficient (and often not available in large quantities) for the level of crop production the farmer is aiming at. Mineral fertilizers have to be applied in addition. Even in countries where a high proportion of organic wastes is utilized as manure and to supply organic matter, mineral fertilizer consumption has risen steadily. The correct kind, time, mode and method of fertilizer application is very important in realizing maximum benefit from the fertilizer use. End