1. Shantappa Duttarganvi M.Sc. (Agri) Dept of Agronomy, 2009

2. Introduction Need of Real-time N management Tools Basic approaches in Real-time N management Challenges of Real-time N management Strategies of N management Variable rate N application Conclusion 3. Continued improvement in cropping system managementBetter prediction of soil N mineralization Improved timing of N application Improved manure management Improved fertilizers 4. .Match the agricultural inputs and practices to localized conditions within field to do the right thing, in the right place, at right time and in right way. (Pierce et al., 1994)The precision agriculture concept wheel based on GPS 5. .Real-time N managementDiagrammatic representation of the relationships between various terms related to Precision Agriculture 6. SSNM provides two equally effective options Real-time N management Fixed time N management 7. Site-specific nutrient management (SSNM)1. Establish a yield target the crops total needs2. Effectively use existing nutrientsFeeding crop needs!3. Fill deficit between total needs and indigenous supply 8. What is Real-time Nmanagement ? 9. Nitrogen is the nutrient that most often limits crop production. (Pathak et al., 2005) Crop use nitrogen inefficiently, generally more than 50% of N applied is not assimilated by plants. (Dobermann and cassman, 2004) Leaching, runoff and denitrification are the processes that result in loss of N from soil-plant system creating the potential for N deficiency in crop. (Nowak et al., 1998) 10. Worldwide nitrogen use efficiency for cereal grains and row crops estimated at only 33 %.Unaccounted 67 % represents a $ 28 billion annual loss of fertilizer N.FAO., 2006 11. To apply nutrients at optimal ratesTo achieve high yield and high efficiency of nutrient use by the rice cropEstimating the total fertilizer N required for rice in a typical seasonFormulating the dynamic N management to distribute fertilizer N to best match the crop need for nitrogen 12. LCCSPADOptical sensor or crop canopy spectralreflectance GIS 13. To develop Site-specific N Management based on crop Nstatus monitoring - Canopy reflectance of light - Chlorophyll content 14. IRRI- 1996 The leaf color chart (LCC) is an easy-to-use and inexpensive diagnostic tool for monitoring the relative greenness of a rice leaf as an indicator of the plant N status. Alam et al., 2005 15. How to use the LCC Select at least 10 disease-free rice plantsSelect the topmost fully expanded leaf and compare the leaf color with the color panels of the LCC and do not detach or destroy the leafMeasure the leaf color under the shade of your bodyDetermine the average LCC reading for the selected leaves 16. Year7MeanRangeMean120 kg N ha-111.2 - 30.420.815.0 - 48.230.910.2 42.727.429.3 53.6 42.79.8 51.528.121.1 51.1 42.1120 kg N ha-17.0 25.415.418.2 50.8 29.19.2 31.219.818.9 58.3 38.9LCC 4 (20 kg N ha-1 as basal) 25RangeLCC 4 (no basal N)2002Treatments7RE (%)LCC 4 (20 kg N ha-1 as basal) 2001AE (kg grain/kg N)LCC 4 (no basal N)2000No. of sites8.5 41.821.618.2 56.3 45.4120 kg N ha-13.8 22.511.316.7 61.7 39.8LCC 4 (20 kg N ha-1 as basal)8.3 - 33. 819.226.3 88.8 58.3Yadvinder Singh et al., 2004 17. TreatmentsGrain yield (kg ha-1)2000Straw yield (kg ha-1)2001Net income (RS ha-1)Benefit cost ratio200020012000200120002001Nitrogen management Control N0 N3008261747934440400134281.321.28LCC value 345573151662445181064647021.791.35LCC value 4576942977702631516152111642.171.81LCC value 554563802759255081448978982.021.56Recommend ed N4342291766084466912333941.661.25CD (P=0.05)336572879820NANANANABudhar (2005) 18. YearDifferent methodsLCC(4) based N managementAE (%)RE (%)Grain Total N yield(t/ha) applied (kg N/ha) 20008620.80.316.639527.40.43FFP6.5312028.10.43-B, LCC6.897915.40.29+B,LCC7.209119.80.39FFP 20026.59+B,LCC 2001-B, LCC6.8412021.60.45-B, LCC6.767111.30.40+B,LCC7.019119.20.58FFP6.6912716.40.53Singh 19. The LCC is a cheapFarmers can easily use the LCC to qualitatively assess foliar N status and adjust N topdressing accordinglyIt helps to manage N for large area leading to improved fertilizer N use efficiencyIt reduces the risks associated with fertilizer N applicationIt saves nearly 26% fertilizer NIt helps to synchronize N supply and crop demand 20. It is a simple, quick and non destructive in situ tool for measuring relative content of chlorophyll in leaf that is directly proportional to leaf N content. 21. 1.2.3. 4. 5.SPAD readings are taken at 9-15 day intervals, starting from 14 DAT for transplanted rice and 21DAS for wet direct seeded rice, Periodic readings continue up to the first (10%) flowering. The youngest fully expanded leaf of a plant is used for SPAD measurement. Readings are taken on one side of the midrib of the leaf blade. A mean of 10-15 readings per field or plot is taken as the measured SPAD value. Whenever SPAD values fall below the critical values, N fertilizer should be applied immediately to avoid yield loss. 22. Nitrogen fertilizer efficiency Rice cultivar Position of leaf on plant Deficiencies of P, Zn, Mn and Fe 23. N ManagementGrain yield(Mg/ha)Total N uptake(kg/ha)Recovery efficiency(%)Agronomic efficiency(%)Well fertilized plot5.05131.435.79.1SPAD based5.05106.461.622.7Fixed timing5.17120.157.618.0Control3.051.0--Hussain et al. (2000) 24. Rice grain yield, N uptake, total fertilizer N applied, and recovery and agronomic efficiency using different need based fertilizer N management criteria N management treatmentGrain yield Mg/haTotal N uptake Kg/ha04.460--T2- Recommended splits1206.11114214.3T3- N30 at SPAD