INORGANIC SOURCES OF FERTILIZERS- Complex, Liquid, Speciality and Nitrogen fertilizers.

Inorganic sources of fertilizers- Straight fertilizers, Complex fertilizers, liquid fertilizers, specialty fertilizers. Nitrogen fertilizers – Crop response-residual effect- improving N use efficiency

1. WELCOME SREENIVASAREDDY.K

2. Topics Inorganic sources of fertilizers- Straight fertilizers, Complex fertilizers, liquid fertilizers , specialty fertilizers. Nitrogen fertilizers – Crop response-residual effect- improving N use efficiency SREENIVASAREDDY.K

3. Fertilizer definition : Fertilizers are materials either natural or manufactured, containing nutrients essential for plant growth and development. or else that any material or substance indeed to be used as nutrient carrier in soil or crops for boosting crop yield as fertilizer 1 SREENIVASAREDDY.K

4. Fertilizer Sales trend in last 6 years Figures in Lakh Metric Tonnes Source: Coromandel’s Internal Finding 2 SREENIVASAREDDY.K

5. CLASSIFICATION OF FERTILIZERS classification based on physical form Solid fertilizers Liquid fertilizers mixed fertilizer Based on chemical reaction Acidic Basic neutral Straight fertilizer complex fertilizer Compound fertilizer Based on fertilizer mixture behaviour 3 SREENIVASAREDDY.K

6. 1. Straight fertilizers Straight fertilizers are those which supply only one primary plant nutrient, namely N/P/K. E.g. Urea. 2. Complex fertilizers Complex fertilizers contain two or three primary plant nutrients are in chemical combination. These fertilizers are usually produced in granular form . E.g:Diammonium phospate 3. Mixed fertilizers : Physical mixtures are straight fertilizers.They contain two or three primary plant nutrients. Mixed fertilizers are made by thoroughly mixing the ingredients either mechanically or manually. 4 SREENIVASAREDDY.K

7. Urea prills  Granulated urea      Ammonium sulphate Solid fertilizers are in several forms : Powder (single superphosphate) Crystals (ammonium sulphate ) Prills (urea, diammonium phosphate, superphosphate), Granules (Holland granules) Supergranules (urea supergranules ) Briquettes (urea briquettes). Liquid fertilizers Liquid form fertilizers are applied with irrigation water or for application. 5 SREENIVASAREDDY.K

8. Inorganic fertilisers raw material  Inorganic fertiliser production explained in simplicity 6 SREENIVASAREDDY.K

9. Mixed or complex – the difference is visible Mixed fertiliser Complex fertiliser 7 SREENIVASAREDDY.K

10. Mixing fertilisers 8 SREENIVASAREDDY.K

11. Complex fertilisers  Example of complex fertilisers in a granular form 9 SREENIVASAREDDY.K

12. Examples of complex fertilisers N % P 2 O 5 % K 2 O % Mg % S % Mo NPK 16-16-16 16 16 16 NPK 6-26-30 6 26 30 DAP NP 18-46 18 46 NP 26-13 26 13 Basfoliar 20 19 19 0.5 0.8 FoliQ MikroMax 0.64 1.29 0.64 Complete fertilisers Complex fertilisers with two nutrients / binary Liquid, foliar fertilisers 10 SREENIVASAREDDY.K

13. The Nitrogenous fertilizers classified into: Ammonical fertilizers Ammonical fertilizers contain the nutrient nitrogen in the form of ammonium ion Except rice, all crops absorb nitrogen in nitrate form. These fertilizers are resistant to leaching loss , as the ammonium ions get readily absorbed on the colloidal complex of the soil. Ammonium sulphate [(NH 4 ) 2 S0 4 ] It is a white salt completely soluble in water containing 20.6 % of nitrogen and 24.0 per cent of sulphur . It is used advantageously in rice and jute cultivation. 11 SREENIVASAREDDY.K

14. Ammonium chloride Ammonium chloride (NH 4 Cl) It is a white salt contains 26.0 per cent of nitrogen. It is usually not recommended for tomato, tobacco and such other crops as may be injured by chlorine. Nitrate Fertilizers Nitrate fertilizers contain the nitrogen in the form of NO 3 ion. These ions are easily lost by leaching because of the greater mobility of nitrate ions in the soil. Continuous use of these fertilizers may reduce the soil acidity as these nitrogenous fertilizers are alkaline in their residual effect on soils. Potassium nitrate (KN0 3 ) The purified salt contains 13.0 per cent nitrogen and 36.4 per cent potassium. 12 SREENIVASAREDDY.K

15. Calcium nitrate Calcium nitrate [Ca 3 (NO) 2 ] It is a white crystalline hygroscopic solid soluble in water containing 15.5 per cent nitrogen and 19.5 per cent calcium. The calcium is useful for maintaining a desirable soil p H. Ammonical and nitrate fertilizers These fertilizers contain nitrogen in both ammonium and nitrate forms. The nitrates are useful for rapid utilization by crops and the ammonical is gradually available Calcium ammonium nitrate (CAN) Calcium ammonium nitrate is a fine free-flowing, light brown or grey granular fertilizer, containing 26 per cent of nitrogen. It is almost neutral and can be safely applied even to acid soils. 50% of its total nitrogen is in the ammonical form and another 50% is in nitrate form 13 SREENIVASAREDDY.K

16. Ammonium nitrate Ammonium sulphate nitrate Ammonium nitrate ( NH 4 NO 3 ) Contain 35 per cent nitrogen half as nitrate nitrogen and half in the ammonium form. In the ammonium form, it cannot be easily leached from the soil. This fertilizer is quick-acting, but highly hygroscopic and not fit for storage . It has an acidulating effect on the soil. Ammonium sulphate nitrate [( NH 4 ) 2 S0 4 NH 4 NO 3 ] It contains 26 per cent nitrogen, three fourths of it in the ammonical form and the rest (6.5 per cent) as nitrate nitrogen. It is a mixture of ammonium nitrate and ammonium sulphate 14 SREENIVASAREDDY.K

17. Urea 4. Amide fertilizers Amide fertilizers are readily soluble in water and easily decomposable in the soil . Urea [CO (NH2 ) 2 ] It is the most concentrated solid nitrogenous fertilizer, containing 46 per cent nitrogen. It is a white crystalline substance readily soluble in water. Calcium cyanamide ( CaCN 2 ) Calcium cyanamide or nitrolime contains 20.6 per cent of nitrogen. It is a greyish white powdery material that decomposed in moist soil giving rise to ammonia. 15 SREENIVASAREDDY.K

18. PHOSPHATIC FERTILIZERS 1.Water soluble phosphoric acid: These available in the form of monocalcium phosphate Suitable for neutral, and alkaline soils Used for short duration crops like wheat,sorghum etc. Ex: SSP , DSP ,TSP, ammonium phophate 2. citric acid soluble phosphoric acid : these fertilisers contain citrate soluble phosphoric acid or dicalcium phosphate They are converted into monocalcium phosphate in acid soils As they are basic reaction suitable for acidic soils Used for long duration crops like sugarcane, tapioka 3. Not soluble in water or citric acid: contain rock phosphate, raw bone meal, steamed bone meal Suitable for strongly acidic soils Suitable for plantation crops 16 SREENIVASAREDDY.K

19. SSP TSP Super phosphate [ Ca ( H 2 PO 4 ) 2 ] This is the most important phosphatic fertilizer in use. It contains 16 Per cent P 2 O 5 in available form. Phosphatic fertilizer hardly moves in the soil and hence they are placed in the, root zone . Triple super phosphate : The concentrated super phosphate is called as Triple super phosphate and it contains 48 per cent P 2 O 5 17 SREENIVASAREDDY.K

20. Common fertilizer sources of K Material Chemical Formula K 2 O Content(%) Potassium chloride KCl 60 Potassium-magnesium sulphate K 2 SO 4 -2MgSO 4 20 Potassium nitrate KNO 3 44 Potassium sulfate K 2 SO 4 50 18 SREENIVASAREDDY.K

21. SECONDARY NUTRIENT FERTILIZERS 19 Calcium fertilizers : Fertiliser % ca 1. Burnt lime CaO -70 2 .Hydrated lime Ca (OH) 2 -50 3.Calcite lime CaCO 3 -36 4.Dolamitic lime CaCO 3 MgCO 3 -17 5. Basic slag [ CaO ] 5 P 2 O 5 SiO 2 -29 6.Gypsum CaSO 4 . 2H 2 O -22 7. Calcium nitrate Ca (NO 3 )22H 2 O - 20 8. Calcium chloride CaCl2 - 36 SREENIVASAREDDY.K

22. SECONDARY NUTRIENT FERTILIZERS 20 Sulphur fertilizers : S% 1. Ammonium sulphate (NH 4 ) 2 SO 4 23 2 .Potassium sulphate K 2 SO 4 18 3 .Magnesium sulphate MgSO 4 13 4 .Super phosphate Ca (H 2 PO 4 ) 2 CaSO 4 12 5 .Gypsum CaSO 4 2H 2 O 18 6 . Aluminium sulphate Al 2 (SO 4 )H 2 O 14 Magnesium fertilizers : Mg% 1 .Magnesium oxide MgO 45 2 . Dolamite CaCO 3 MgCO 3 12 3 . Kiserite MgSO 4 H 2 O 18.2 4 . Langbeinite K 2 SO 4 2MgSO 4 11.2 5 .Magnesium sulphate MgSO 4 7H 2 O 10.5 SREENIVASAREDDY.K

23. Micro nutrient fertilizers source nutrient content(%) Ferrous sulphate 19 Ferric sulphate 23 Ferrous ammonium sulphate 14 Iron chelates 14 Zinc sulphate 35 Zinc chelate 14 Zinc oxide 78 Borax 14 Boric acid 17 soulbor 20 Copper sulphate 21 Copper ammonium phosphates 30 Manganese sulphate 26 Manganese chelates 12 21 SREENIVASAREDDY.K

24. Changes that occur while manufacturing mixed fertiliser  The following important principles must be taken into consideration while preparing mixed fertilisers. All fertilizers containing ammonia are not mixed directly with the alkali fertilisers (e.g. rock phosphate and limestone) as reaction will take place resulting in the loss of gaseous NH 3 . The water – soluble phosphates are not mixed with those materials which contain free lime (e.g.) lime stone, CaCN 2 ) as there will be reaction towards the reversing of water – soluble phosphate to water – insoluble phosphates. Hygroscopic fertilisers are not included as they will facilitate caking up. The acidic fertilisers are likely to produce some free acids which may damage the container or packing materials. 22 SREENIVASAREDDY.K

25. Summing up on differences on complex, mixed and other inorganic fertilisers  Mixed fertilisers ;  Mixed fertilisers are relatively cheap but has many disadvantages, such as a requirement to avoid unwanted chemical reactions and segregation, being a challenge also for representative sampling.  Complex fertilisers ;  Complex fertilisers are easy to use (and to sample), but they are more expensive and it is in fertilisation almost impossible to avoid imbalances of nutrients.  Liquid fertilisers ;  Liquid fertilisers , here under foliar fertilisers are not used much, and the use is typically for high value productions, such as flowers and fruit plantations. 23 SREENIVASAREDDY.K

26. L iquid fertilizers Starter solutions : Solutions of fertilizers, generally consisting of N-P 2 O 5 – K 2 O in the ratio of 1:2:1 and 1:1:2 are applied to young vegetable plants at the time of transplanting. It helps in the rapid establishment of seedlings and quick early growth. Advantages : i) The nutrients reach the plant roots immediately and ii) The solution is sufficiently diluted so that it does not inhibit growth. Disadvantages : i) Extra labour is necessary and ii) Fixation of phosphate is greater. 24 SREENIVASAREDDY.K

27. Direct application to the soil With the help of special equipment , anhydrous ammonia (a liquid under high pressure up to 200 PSI or more) and N solutions are directly applied to the soil . It allows direct utilization of the cheapest N source. Application through irrigation water Straight and mixed fertilizers containing N, P & K easily soluble in water , are allowed to dissolve in the irrigation stream . The nutrients are thus carried in solutions. This saves the application cost and allows the utilization of relatively in expensive soluble fertilizers, like N-fertilizers 25 SREENIVASAREDDY.K

28. Ways of storing liquid fertilisers 26 SREENIVASAREDDY.K

29. Foliar application It refers to the spraying on leaves of growing plants with suitable fertilizers solutions. These solutions may be prepared in a low concentration to supply any one plant nutrients. It is preferable to soil application when The soil conditions or a competitive crop makes nutrients from soil dressing unavailable , like late application of N to crops raised under Rainfed condition, An accurately time response to fertilizers is required. 27 SREENIVASAREDDY.K

30. Specialty fertilizers: Recently new generation fertilisers have been introduced exclusively for foliar application and fertigation are called specialty fetilizers Foliar nutrients are rapid and efficient use of nutrients for correcting plant nutrient deficiencies These fertilizers have varying ratios of major, secondary and micronutrients Ex: multi- K , Polyrice , Polycot 28 SREENIVASAREDDY.K

31. Water-soluble specialty fertilizers is new technology in India and is used mainly through ‘ fertigation ’ techniques such as drip irrigation and sprinklers. The demand for these fertilizers increased rapidly in the wake of the recent spate of droughts, as these ensure uniform distribution of nutrients due to their unique properties. Consumption of this fertilizer is growing at 18-20 per cent annually. 29 SREENIVASAREDDY.K

32. The ‘ideal fertilizer’: the nutrient release is synchronized with the crop’snutrient requirements ( Source: Lammel , 2005). SREENIVASAREDDY.K

33. Sulphur Coated Urea Solid Urea H 2 O H 2 O Solid Urea Solid Urea Sulfur Coating H 2 O Dissolved Urea H 2 O H 2 O + S 30 SREENIVASAREDDY.K

34. CONTROLLED RELEASE(CR) FERTILIZERS : A synthetic fertilizer, usually encased in capsules, that releases its nutrients over a specific period of time much the same as a controlled-release drug releases its medicine Example : Meister®- polymer-coated urea, Nutricote ® 31 SREENIVASAREDDY.K

35. Polymer Coatings Remain Intact Water Dissolved Urea Solid Urea Dissolved Urea Water Dissolved Urea Complete Release 32 SREENIVASAREDDY.K

36. 33 SREENIVASAREDDY.K

37. What are advantages speciality fertilizers ? For specific uses , specialty fertilizers may be preferred.  Recently new generation specialty fertilizers have been introduce exclusively for foliar application and fertigation . They are highly water soluble with low salt index. These fertilizers have varying ratios of major secondary and micronutrients . They are compatible with most of the commonly used insecticides and fungicides . EXAMPLES: Multi-K (13-0-46), Poly feed (19-19-19) 34 SREENIVASAREDDY.K

38. PRODUCT Available Nutrients % As   NO 3 NH 4 NH 2 P 2 O 5 K 2 O MULTI -K ( 13-00-46) 13.2   - - 46 Poly feed : 19-19-19 5 4 10 19 19 MAP (12-61-00) - 12.5 - 61 - MKP (00-52-34) - - - 52 34.5 Speciality Fertilizers 35 SREENIVASAREDDY.K

39. MULTI – K Potassium Nitrate 13-00-46 MAP Mono Ammonium Phosphate 12-61-00 MKP Mono Potassium Phosphate 00-52-34 Polyfeed NPK Blend 19-19-19 Polyfeed NPK Blend 13-40-13+ 2MgO Polyfeed (Non-nominated FCO Grade) NPK Blend 15-15-30+ME SOP Sulphate of Potash 00-00-50 Calcium Nitrate Calcium Nitrate 15.5-00-00-19 Science direct.com.,2011 36 SREENIVASAREDDY.K

40. Crop Specialty Fertilizer Concentration (%) Number of sprays Stage to be sprayed Rice Polyfeed 1% 1 Maximum tillering (45 DAP)   Multi-K 1% 1 Grain filling (75 DAP) Maize Polyfeed 1% 1 Knee high (45 DAS)   Multi-K 1% 1 Grain filling (75 DAS) Soybean Polyfeed 1% 1 Maximum vegetative (45 DAS)   Multi-K 1% 1 Grain filling (60 DAS) Sunflower Polyfeed 0.50% 1 Grain floret (60 DAS)   Multi-K 0.50% 1 Grain filling (75 DAS) Cotton Polyfeed 1% 1 Square formation (60-75 DAS) 37 SREENIVASAREDDY.K

41. Environmental losses of N Volatil i zati o n Denit r ific a tion Leaching Runoff N O 3 - NH 3 atmosphere N 2 O SOIL SYSTEM N O 3 - NH 4 + to groundw a ter surface waters to surface water 38 SREENIVASAREDDY.K

42. Nitrogenous fertilizers Nitrogen is one of the major essential elements required by all plants It is most deficient in indian soils Current consumption of nitrogen fertilizers reach to 11 m.t Only urea fertilizer account for 82% of total nitrogen consumption U.P, Punjab, A.P states account for 52.8% of total nitrogen consumption due to their size , high cropping intensity, better irrigation facilities and HYV Rice and wheat accounts for 66.9% of total nitrogen consumption 39 SREENIVASAREDDY.K

43. Crop response to nitrogenous fertilisers : 1.Cereals,millets,pulses,tubers and fibre crops respond better to applied nitrogen 2.Lower dose of nitrogen give higher response 3.The response of the same crop varies greatly with soil type 4.The advanced techniques result in better response and higher grain yield 5.Rainfall pattern and water holding capacity have their direct bearing on N-response 6.N gives better response only when P & K deficiencies are corrected 40 SREENIVASAREDDY.K

44. Out of total N uptake by rice 50% is absorbed by the early P.I stage Nutrient uptake by maize is particularly high from 10 days before until about 25-30 days after tasseling stage During grain formation stage much nitrogen is translocated to the grain 10-12 kg rice /kg applied N is generally obtained on cultivars fields HYV rice resoponds upto 100 kg N/ha in kharif , up to 120 kg N/ha in rabi HYV wheat responds 120 kg N/ha and gave response rate about 41 SREENIVASAREDDY.K

45. Pulses : Require only starter dose of 15-25 kg N /ha Higher dose of N enchourages vegtative growth , decreases H.I OILSEEDS : oil content in ground nut increases up to 20 kg N/ ha, where as increase in protein content was recommended up to 40 kg/ha 75 kg N /ha increases oil content in mustard Fibre crops : Application of N increases cotton yield and seed index response up to 8-10 kg seed cotton /kg nitrogen are obtained Hybrids responds up to 300 kg N/ha ,local varieties responds more than 100 kg /ha 42 SREENIVASAREDDY.K

46. Excessive N delays maturity in cotton boll worm attack and decrease yield and quality In jute fiber strength and fineness is superior at lower to moderate dose of nitrogen Response of dryland crops to nitrogen : Reponse to applied nitrogen depends upon water availabulity and the sufficiency of other nutrients High response obtainable only under favourable rainfall situations & with efficient insitu moisture conservation 43 SREENIVASAREDDY.K

47. Residual effects of Nitrogen Number of studies indicated that unlike P, K or micronutrients there is no significant residual effect of N applied to rice on the yield of succeeding wheat crop When wheat follows an exhaustive crop like sorghum / pearlmillet an extra of 25% N is advocated Carry over effects of N applied to rice on the succeeding crop be large when slow release of coated N carriers are used in rice but potential yields could not be applied only by residual fertility 44 SREENIVASAREDDY.K

48. Nitrogen use efficiency NUE is defined as the ratio between the amount of fertilizer N removed from the field by the crop and the amount of fertilizer N applied . Efficiency of applied nitrogen is around 30% in rice due to un favourable soil environment Low N fertilizer use efficiency is attributed due to improper water and nitrogen management, imbalanced fertilizer use, in apprpriate crop husbandry and nitrogen losses from soil 45 SREENIVASAREDDY.K

49. Nitrogen Use Efficiency Variables which influence N use efficiency include a. Variety b. N source c. N application method d. Time of N application e. Tillage f. N rate (generally decreases with increasing N applied) g. Production system 1. Forage 2. Grain 46 SREENIVASAREDDY.K

50. IMPROVED FERTILISER N USE EFFICIENCY : Fertilizer application to coincide with crop Split application Balanced use of NPK fertilizers Deep placement/incorporation of fertilizers Use of slow release or nitrification inhibitors Integrated nutrient management LAND MANAGEMENT PRACTICES; Recommended water management practices to minimise leaching losses Tillage to control surface run off Agronomic practices to reduce soil erosion and runoff Recycling of organic residues Use of farm yard manure and compost 47 SREENIVASAREDDY.K

51. RESEARCH EVIDENCES SREENIVASAREDDY.K

52. Treatment Black soil Red soil Mean CONTROL 4.69 4.58 4.64 PU 7.21 7.14 7.18 SCU 7.58 7.51 7.55 NCU 7.49 7.43 7.46 TCU 7.51 7.46 7.49 LCU 7.37 7.26 7.32 GCU 7.46 7.36 7.41 UMB 7.50 7.34 7.48 Mean 7.18 7.06 7.42 Venkateswara rao v , 1990 Table 1: Effect of forms of slow release urea fertilizers on grain yield(g per hill) of Rice in Black and Red soils PU- Prilled urea , SCU-sulphur coated urea , NCU- Neem coated urea TCU- Tar coated urea , GCU-gypsum coated urea , UMB- urea in mud ball 48 SREENIVASAREDDY.K

53. Grain yield(g/pot) ANR(%) Separate compounds compacted Separate compounds compacted Prilled urea 18.3 18.6 38.2 38.6 Urea-Fe 17.9 21.3 41.9 45..9 Urea- Mn 19.7 22.3 43.2 49.8 Urea-Zn 20.4 23.8 45.7 52.1 Urea-Cu 20.5 24.4 48.6 58.0 CD(p=0.05) 1.5 0.9 8.3 5.3 Effect of urea –micronutrient formulations on grain yield and apparent nitrogen recovery(ANR) by rice chhonkar et.al,2006 Journal of indian society of soil science,vol.54,no.1,80-85 49 SREENIVASAREDDY.K

54. Effect of Different Slow Release Nitrogen Fertilizer Forms on Yield and Chemical Constituents of Maize and Soybean Abou-Zied et. al .,(2014) Middle East Journal of Agriculture Research, 3(3): 645-652, 2014 5 SREENIVASAREDDY.K

55. Generally, higher moisture availability results in higher yields at comparable N supply levels, as well as a greater response to applied fertilizer N. Lower moisture availability not only restricts response and yield potential, but also results in higher crop protein contents, particularly at higher levels of available N. Better crops ,2000 40(1) pp-243-245 51 SREENIVASAREDDY.K

56. Total loss of nitrogen(NH 4 +NO 3 ) from different nitrogenous fertilizers in lateritic soil J. H. Dongal et. al ., (2002) Treatment NH 4 -N %loss NO 3 - N %loss Loss as %of the Applied N Control(with out crop ) 8.9 91.1 - AS 7.35 92.65 14.65 Urea 6.04 93.96 11.94 CAN 4.68 95.32 37.63 Control(with crop) 5.17 94.83 - AS 6.67 93.33 35.60 Urea 3.86 96.14 32.58 CAN 4.19 95.81 64.75 CD (0.05) 1.5 1.5 - Journal of indian soc.Coastal agric.Res . 2002,2(2),51-56) 5 2 SREENIVASAREDDY.K

57. N-levels Agrnomic efficiency(kg cob/ kgN ) Physiological efficiency(kg cob/kg N uptake ) Crop productivity(kg fresh kernal /day/ha) Crop profitability (Rs/ha/day) Net returns(x 1000 rs /ha) Net returns per rupee invested(RS) - - 32.4 165.7 17.07 2.53 30 146.8 86.5 54.7 374.2 38.54 4.35 60 94.2 76.1 59.4 458.8 47.26 5.03 90 77.6 74.6 71.3 552.4 56.91 5.73 120 66.7 72.8 79.0 635.9 65.49 6.35 150 54.1 69.3 79.9 641.8 66.11 6.28 CD(0.05) 8.6 6.4 5.3 42.6 4.6 0.41 Effect of different N-levels on nitrogen use efficiency and economics of sweet corn Ummed singh et .al , ( 2012) Indian journal of agronomy ,57:43-48,2012 5 3 SREENIVASAREDDY.K

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60. Treatments Grain yield(t/ha) Straw yield(t/ha) Agronomic efficiency(t/ha) Physiological efficiency N-uptake efficiency panicles/m2 Panicle weight N levels Control 2.47 3.89 - 55.32 44.65 284 2.54 50 kg 3.75 5.62 24.15 54.50 68.69 294 2.88 100kg 5.61 8.15 26.5 54.38 103.16 306 3.02 150kg 6.30 9.48 24.15 51.17 123.11 299 3.13 CD(0.05%) 0.14 0.45 1.20 2.14 1.77 9.0 0.10 Varieties PHB-71 4.86 7.27 26.10 50.44 96.36 314 2.98 KRH-2 4.50 6.84 26.04 53.20 84.58 305 2.96 NDRH-2 4.81 7.46 25.67 50.06 96.08 322 3.24 NDR-359 4.04 6.24 21.90 57.66 70.07 269 2.60 Effect of nitrogen levels on grain yield ,yield attributes,N -use efficiency and N-uptake of rice S.F.A.Zaidi et.al (2007) Oryza vol.44.no.2,2007(181-183) 5 6 SREENIVASAREDDY.K

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