1. Nutrient recycling through agricultural and industrial wastes - potential and limitations Pravash Chandra Moharana Roll No. 4805 Division of Soil Science & Agricultural Chemistry Indian Agricultural Research Institute New Delhi-110 012

2. Contents Introduction Nutrient recycling through Crop residues Animal wastes Industrial wastes Methods of recycling Effect of wastes on soil nutrients availability Limitations Conclusions Future steps 3. Why we go for nutrient recycling through waste?? Due to intensive agriculture, the soil resource is under increasing stress as there is a big gap between annual output of nutrients from soil due to crop removals and the nutrient inputs from external resources. So, filling this gap we go for non conventional resources. According to a conservative estimate, around 600 to 700 Mt of agricultural wastes available in India every year, but most of it is not used properly. We must convert this waste into wealth by mobilizing all biomass in bioenergy and supply nutrients to the soil. 4. Recyclable resources Agricultural residues Crop residues like wheat straw, rice straw, sugarcane trash, etc. Forest litter and aquatic weeds like water hyacinth Livestock wastes Cattle waste, poultry waste, piggery waste, goat and sheep excreta Agro industry wastes Oil cakes, by-product of sugar industry, vegetable and fruit processing wastes Municipal solid wastes (MSW) House wastes, market wastes, etc. Industrial wastes Tannery, textile, distillery and paper mill effluents, wastes from mineral processing, fly ash, etc. 5. Recycling of agricultural wastes 6. Nutrient recycling through crop residues Crop residues are the remnants of crop plants left after harvest of crop. Estimates of crop residues production (106 Mg) in the world (Lal, 2005) Total NPK assimilated in crop residue are estimated at about 25, 4, and 40 Tg in world, equivalent to approximately 30%, 30%, and 200% of the amount of each nutrient respectively, contained in available chemical fertilizers (Zhang et al., 2008) 7. Estimates of crop residues production in India (2002-03) Crop Crop production (Mt) Crop residue (Mt) Crop residue available for recycling (Mt) Nutrient (NPK) available for recycling (Mt) Fertilizer (NPK) equivalent value for recycling (Mt) Rice 72.65 108.97 36.32 0.788 0.394 Wheat 65.10 97.62 32.52 0.586 0.292 Sorghum 7.08 10.62 3.54 0.074 0.034 Bajra 4.63 6.94 2.31 0.040 0.020 Maize 10.30 15.45 5.15 0.105 0.053 Pulses 11.14 11.14 3.71 0.122 0.061 Oil seeds 15.06 30.12 10.04 0.195 0.097 Soybean 4.56 9.12 3.04 0.972 0.049 Groundnut 4.36 8.72 2.90 0.093 0.046 Sugarcane 281.57 281.57 93.85 1.746 0.873 Potato 23.16 23.16 7.72 0.138 0.069 Total 499.6 603.39 312.5 6.46 2.1 Panwar and Ramesh, 2009 8. Crop residue Nutrient (%) N P2O5 K2O Rice 0.61 0.18 1.38 Wheat 0.48 0.16 1.18 Maize 0.52 0.18 1.35 Pearl millet 0.45 0.16 1.14 Potato tuber 0.52 0.21 1.00 Groundnut (pods) 1.60 0.23 1.37 Sugarcane 0.40 0.18 1.28 Pulses 1.60 0.51 1.75 Nutrient content in crop residues Reddy and Reddy, 2003 9. Crop residue burning More than 15 Mt of rice straw and 9 Mt of wheat straw are burned annually in three states of Punjab, Haryana and Uttar Pradesh. Farmers burn the residues in machine harvested fields, as it is easy and quick approach for disposal of residue Incorporation of residues does not show immediate benefits to the farmers and requires special tillage machinery. Gupta et al., 2004 10. Nutients lost via residue burning Nutrients kg t-1 of rice residue kg t-1 of wheat residue % lost during burning N 6.0 5.0 82 P 1.0 0.8 44 K 15 10.0 40 S 1.4 1.4 81 Ca 2.8 3.0 52 Mg 12 1.2 47 C 414 400 80 Gupta et al., 2004 11. Animal wastes refer mainly to dung and urine along with bedding and mixed soil These wastes available in dairies, slaughter houses and rural area Unfortunately, nearly 50% of the cattle dung production in India today is utilized as fuel and is thus lost to agriculture Amount and quality of excreta of animal depends upon Age and weight of the animal Total quantity of fodder and concentrates fed daily to the animals Recycling of animal wastes 12. Annual production of animal wastes and their composition Animal type Populatio n (million) Daily Excretion/animal Composition (%) Dung (kg) Urine (L) N P2O5 K2O Cattle 283 11.5 7.5 0.8-1.2 0.2-0.4 0.35-0.65 Poultry 490 0.07 - 2.5-3.0 1.0-1.13 0.7-1.2 Pigs 14 2.0 2.0 0.5-0.53 0.5-0.53 0.3-0.36 Goat and sheep 186 0.3 0.2 2.5-3.0 0.3-0.4 1.5-1.7 Panwar and Ramesh, 2009 Animal wastes produce in India around 2046.8 Mt which can potential supply 17.77 Mt plant nutrients Poultry manures are produced 8.0 Mt which is sufficient to fertilize about 3.56 Mha of land annually 13. Agro-industrial wastes Nutrient potential in agro-industrial wastes in India Source Total quantity available (Mt) Total NPK (Mt) Rice mill waste 20 0.24 Cotton mill waste 12.04 0.0913 Tea industry waste 0.012 0.0006 Jute waste 3 0.034 Pressmud 5 0.42 Veg. & food processing ind. wastes 0.03 0.0005 Oil cakes 4 0.36 N content in oil cakes varies 3-9% and C:N ratio 3-15 Press mud content 1.25 %N, 4.40% P2O5 and 20-25% organic matter. It is highly beneficial in acidic soils as it contains up to 45% lime. Panwar and Ramesh, 2009 14. Nutrient content of edible and non-edible oilcakes Edible oilcake sources N % P2O5 % K2O % Kg N + P2O5 + K2O per tonne of cake Groundnut 7.29 1.65 1.33 103 Mustard 4.52 1.78 1.40 77 Rapeseed 5.21 1.84 1.19 82 Sesame 6.22 2.09 1.26 96 Coconut 3 1.9 1.8 67 Sunflower 7.9 2.2 1.9 120 Non-edible oilcake Castor 4.37 1.85 1.39 76 Neem 5.22 1.08 1.48 59 Karanj 3.97 0.94 1.27 62 Mahua 3.11 0.89 1.48 59 Tandon,1997 15. Industrial wastes Distillery effluents Paper mill effluents Tannery effluents Textile Industrial effluents Wastes from metal refining and processing(Basic slag, phospho-gypsum, etc.) Fly ash 16. 285 distilleries in India produces 40 billion litres of effluents which can provide 480000 t of K, 52000 t of N and 8000 t of P annually. 3000 tanneries in India mostly spread over Tamil Nadu, West Bengal, Uttar Pradesh, Maharashtra, Karnataka, Punjab and Rajasthan which discharged effluents 30 to 40 liters per kg of skin/ hide processed (Chhonkar et al., 2000) A large paper mill on an average generates 2270 m3 of effluent, containing 1484 mg L-1 of total dissolved solids daily (Hazarika et al., 2007) Status of industrial effluents in India 17. Property Values (mg L-1 ) Total N 5.06 Total P 3.0 Total K 47.5 Sulphate 21.3 Total Na 337 Total Ca 240 Chloride 530 Total Cu 0.016 Total Ni 0.007 Total Pb 0.021 Total Zn 0.24 Composition of Nagaon paper mill effluent, Assam Hazarika et al., 2007 Long term irrigation causes soil salinity and heavy metal accumulation 18. Addition of nutrients with distillery effluent irrigation Treatment Effluent N P K SO4 kL ha-1 Kg ha-1 . Dilution 1:20 200 60 4.0 1200 200 Dilution 1:10 400 120 8.0 2400 400 Dilution 1:5 800 240 16.0 4800 800 Dilution 1:3.3 1200 360 24.0 7200 1200 Joshi et al., 1996 Sugarcane can withstand application of concentrated effluent without showing any reduction in yield whereas cereals like wheat and rice grow well on dilution 1:20 19. SAIL steel plants produce 10 Mt of solid wastes (flyash, slags and flue dusts ) per year Slags produced by iron and steel-making have been used historically in agriculture as lime substitute. Blast furnace (iron) slag high calcium carbonate equivalence (CCE) value (80-100%). Basic slags are produced from high-P iron ores and have a high P content (4-8%) as well as considerable CCE (40-60%). Certain metal alloyed in steel (Ni, Cr, Mo) may be present in the slag and should be carefully monitored in any land application. Utilization of Basic slags in agriculture 20. Utilization of fly ash in agriculture Fly ash derive from burning coal in electric generating and steam plants It is a fine (typically