Fertilizer Use Efficiency.pdf soil science
- 2. • Fertilizer use efficiency of N, • Fertilizer use efficiency of P, • Fertilizer use efficiency of K, • Fertilizer use efficiency of S, • Fertilizer use efficiency of Fe and • Fertilizer use efficiency of Zn fertilizers
- 3. • NUE may be defined as yield per unit input. • Input refers to input of fertiliser. • NUE is often expressed as fresh weight or yield per content of nutrient. • NUE not only depends on the ability to efficiently take up the nutrient from the soil, but also on the transport, storage, mobilization, usage within the plant, and even on the environment. • Hence, nutrient use efficiency is defined as the extent to which the nutrients and management practices interact to give a specified yield level. • Improvement of NUE is esp. important crop production in marginal lands with low nutrient availability.
- 4. Yield with applied nutrient – yield without applied nutrient NUE (%) = ---------------------------------------------------------------- x 100 Amount of nutrient applied
- 6. Factors affecting NUE A. Soil factors : The most important factors are soil physical conditions, soil fertility and soil reaction. • Physical conditions: Soil moisture content: very poor soil moisture adversely affect nutrient absorption Drainage : Ill-drained conditions affect nutrient uptake. Clay content: Higher clay content more is nutrient holding capacity. Nitrogen and potassic fertilizers should be more frequently applied than in fine textured soils. Aeration : Under poor aeration uptake is reduced Soil temperature: At high soil temperatures nutrients will not be used efficiently.
- 7. • Fertility status: The higher the fertility status of the soil, the lower is the response. The higher the organic matter status, the more is the nutrient use efficiency. • Soil reaction: is an important factor which decides the availability of nutrients. Soil pH decides the selection of right type of fertilizers especially P
- 9. B. Climatic factors : include temperature, rainfall and its distribution, evaporation, length of day and growing season. Rate of nitrification is slower in cooler climate than in warmer climate, hence more amounts of fertilizers should be added in cool climate. Higher amount of fertilizers are required in high rainfall region due to leaching to obtain an expected yield potential. In arid regions, soil moisture is a limiting factor to get higher nutrient use efficiency. The higher the light intensity, the better is the nutrient use efficiency.
- 10. C. Crop factors : CEC of plant roots influences the fertilizer responsiveness of the crop. Root Structure: A large ramifying root system of the plant absorbs nutrients more efficiently. The critical stages of crop require assured nutrition which must be matched with the pattern of fertilizer application to increase nutrient use efficiency. For legumes N fertilizer may be reduced as they can fix atmospheric N to increase N use efficiency.
- 11. D. Agronomic factors : include • selection of fertilizer responsive crops and varieties, • timely sowing, • proper spacing, • proper dose, time and method of fertilizer application to increase the yield and thereby increasing NUE.
- 12. How to enhance nutrient use efficiency 1.Selection of suitable crops and varieties, which are input responsive recommended for the region 2.Sowing or planting the crops at optimum time 3.Maintaining optimum plant population 4.Use of organic manures and biofertilizers to supplement nutrients and also to bring ideal conditions for crop growth 5.Inclusion of legumes in the cropping system as intercrop
- 13. 6. The crops should be irrigated at least to save life at critical growth stages 7. Fertilizer scheduling must be based on soil test values to prevent nutrient deficiencies or luxury consumption 8. P and K fertilizer and part of N fertilizer should be applied as basal and N in splits doses; for light textured soils K also should be applied in splits 9. Band placement of fertilizers preferable to prevent losses. (Especially P to reduce fixation).
- 14. 10. Under moisture stress condition, foliar application of urea at 2% concentration is effective 11. Micronutrient deficiencies should be corrected instantly 12. ZnSO4 should be applied as package once in two seasons @ 25-50 kg/ha 13. Problem soils must be ameliorated by taking reclamation measures
- 15. 4. Site-specific N Management Nitrogen Use Efficiency : 1. Fertilizer Source 2. Slow-release N fertilizers, Urease and Nitrification Inhibitors 3. Method and Time of Fertilizer Application 5. Fertigation & Foliar application
- 16. 9. Remote-sensing and Geographic Information System Technologies 6. Balanced Use and Interaction of Nitrogen with Other Nutrients 7. Integrated Nutrient Management 8. Simulation Modelling Technique for Cereals
- 17. 1. Fertilizer Source: • NH4, NO3 is form in which it is absorbed • Ammonical more preferred than NO3 owing to its lesser loss through denitrification • Crop preference is considered. (rice- ammoniacal, tomato, celery – nitrate etc)
- 18. 2. Slow-release N fertilizers, Urease and Nitrification Inhibitors: • use of products to slowly release N • slow the nitrification of applied N • to synchronize the supply of N with the crop demand and • decrease N losses via leaching • delay denitrification. Slow release fertilizers: eg., Urea formaldehyde, urea super granule (USG), sulphur coated urea, neem cake coated urea, neem oil coated urea, nimin and polymer coated urea May, 2015 Government of India has made mandate to coat all Urea with Neem Oil.
- 19. Nitrification inhibitors: eg., N-serve, AM (2-amino-4-chloro-6-methyl pyrimidine), DCD- dicyandiamide Urease inhibitors: eg., PPDA (Phenyl Phosphorodiamidate), NBPT ( N-buty1 thiophosphoric triamide), PMA (Phenyl mercury acetate)
- 20. 3. Method and Time of Fertilizer Application: • Being soluble in water, leaching losses are high • Fertilizer N is usually recommended in two or three splits • Split application of nitrogenous fertilizers to prevent losses due to leaching. 4. Site-specific N Management: • N-content in standing crop is measured by employing certain diagnostic tools such as chlorophyll meter and leaf colour chart (LCC). • Since most of the plant N is found in chloroplasts and chlorophyll protein, the N-content of the plant could be ascertained by using chlorophyll meter or LCC. • Employs RS-GIS techniques
- 21. 5. Fertigation and Foliar Application: • Application of fertilizers through irrigation water, including drip system, is termed as Fertigation. • It provides the most effective way of supplying nutrients to the plant roots. • Drip irrigation system can save fertilizer N up to 40%. • Results showed a saving of 20-25% of the fertilizer under drip Fertigation in vegetable & fruit crops • Under drip NO3 —N is higher in the upper soil layers compared to broadcast application leading to less leaching losses.
- 22. 6. Balanced Use and Interaction of Nitrogen with Other Nutrients • Complementary and antagonistic effects among nutrients are known. • Interaction can be defined as the changes brought about by one factor on the effect of another factor, which may be either positive or negative. • Application of K fertilizers would liberate NH4 from clay complex
- 23. 7. Integrated nutrient management (INM) • INM pools together the opportunities offered by the different sources of a nutrient such as fertilizers, organics and biological to meet the requirements of a crop. • Fertilizer remains as the fulcrum of INM, without degrading the soil and water resources. • The INM helps in maintaining balanced nutrients supply, checking micronutrients deficiencies and sustaining crop yields at a higher level, besides improving physical and biological properties of soil. • By the integration of inorganic N with organic sources the soil physical condition can be optimized besides adding nutrients to the soil.
- 24. 8. Simulation Modelling Technique for Cereals • Certain computer stimulated models offer alternate methods to increase NUE • Eg., APSIM (Agril. Production Systems Simulator) 9. Remote-sensing and Geographic Information System Technologies • Crop scenario can be remotely sensed through satellite imagery and required correction measures can be planned before crop is affected.
- 25. P use efficiency can be increased by decreasing P fixation and balanced application of the nutrients. P fixation can be reduced by judicious application of organic manures, application of P fertilizer by placement, inoculation (either seed or soil) with phosphorus solubilising bacteria like Pseudomonas, Bacillus megathrium var. phosphaticum.
- 26. 1 Time of Phosphorous Application : Basal & never as split 2. Methods of Phosphorous Application: Placement 3 Liming of Acid Soils: The beneficial effect of liming acidic soils on crop yields and improvement in the availability of P is well established. 4. Treatment of Planting Material with Phosphorus: The beneficial effect of soaking is maximum in low P-soils. The use of 0.4% solution of MAP, DAP or filtered SSP also increases P-uptake and potato yields.
- 27. 5. Role of Mycorrhizal Fungi: Certain mycorrhizal fungi, known as VAM (Vesicular Arbuscular Mycorrhizae) colonize plant roots and through this symbiotic association, help the plant to absorb more P in two ways (a) VAM increase root volume - mycelia could act as an extension of the root system, enabling the plant to explore a larger soil volume resulting in a greater flow of P into the roots, and (b) Form arbuscules which hold phosphorus - Roots colonized by VAM are more efficient in absorbing P from low-P soils.
- 28. 6. Role of P-solubilizing Microorganisms: • The role of P-solubilizing microorganisms (PSM) in enhancing dissolution of insoluble and sparingly- soluble P was known • Bacteria namely Bacillus megaterium and Pseudomonas striata • Fungal species namely Aspergillus awamori is reported to add 30-35 kg P2O5/ha under ideal conditions.
- 29. 7. Incubation of Insoluble Fertilizers with Organic Manures: • The efficiency of rock phosphate can be increased in alkaline soils (pH 8.3) by preincubation with fresh cattle dung • Some compost enriched with rock-P, or “Phospho- composts” as these are called, have been developed and are effective in increasing the efficiency of P and crop yields. • Use of farmyard manure (FYM) also increases the efficiency of rock P.
- 30. K use efficiency : • can be enhanced by preventing leaching losses • either by split application on light soils, • applying organic manure and balanced application of nutrients.
- 31. S use efficiency : Sulphur in soil solution is present as SO4 = hence subjected to losses which can be prevented by • applying organic manures to improve water holding capacity of the soil and it also acts as a source of S. • S oxidation can be facilitated by providing oxidized conditions in the soil.
- 32. Fe use efficiency : • Most available form of iron is Fe2+. Fe availability is more in acidic soil pH. • Application of organic manures including green manuring improve the use efficiency of iron by 1.Acidifying the rhizosphere due to the release of organic acids 2.Supplementing with iron after decomposition 3.Act as substrate for heterotrophic bacteria that can reduce ferric to ferrous form (eg., Bacillus, Clostridium and Klebsiella etc.). 4.The microbes also produce chelating ligands called as ‘siderophores’ that can form complex with Fe3+, which can be absorbed into the plant. • Reclamation of alkali soils • If deficiency appears on standing crop foliar application of Fe.
- 33. Zn use efficiency • Taking care of antogonistic nutrients to Zn: Zn fertilizer should not be applied with phosphatic fertilizers. • Maintaining the soil pH between 5.5 – 6.5 by applying organic manures.
- 34. Summary • Nutrient use efficiency • Soil, plant and management factors influencing NUE • How to increase NUE • Measures to increase Use Efficiency of • Fertilizer use efficiency of N, • Fertilizer use efficiency of P, • Fertilizer use efficiency of K, • Fertilizer use efficiency of S, • Fertilizer use efficiency of Fe and • Fertilizer use efficiency of Zn fertilizers