Climate Change & Soil Resource Productivity
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The presentation discusses the impact of climate change on soil productivity, highlighting the challenges posed by deforestation, agricultural mismanagement, and human population growth. It addresses the consequences of high-input agricultural practices, including soil erosion and chemical pollutants, as well as the need for conservation methods. Recommendations for sustainable land use and water management strategies are presented to mitigate these issues.
Climate Change & Soil Resource Productivity
- 1. Climate Change & Soil Resource Productivity Climate change Soil productivity decline P.B. Dharmasena – Presentation made on 8th June 2012 at the UNDP workshop on ‘Climate Change and Soil Resource Productivity’ at Vavuniya
- 2. Climate Change & Soil Resource Productivity Climate change Soil productivity decline Deforestation Mis-management of land Mis-practices of agriculture
- 3. Human population growth, forest decline and green revolution 0 5 10 15 20 25 30 1870 1890 1910 1930 1950 1970 1990 2010 2030 0 10 20 30 40 50 60 70 80 90 Forest Population Sri Lankan trend
- 4. • High yielding varieties • Mechanized agriculture • Chemical fertilizer and agro- chemicals • Commercialized agriculture Green Revolution
- 5. Impacts • High yielding varieties – High input requirements, susceptible to pest and diseases, drought, salinity etc. • Mechanization - soil environment – physically disturbed – Soil erosion, nutrient loss, water loss, weed problem • Chemical fertilizer and agro-chemicals – soil acidity, heavy metals, micro-nutrients deficiency, health hazards etc.
- 6. Highly erosive rainfalls occur in low lying areas – Dharmasena (1992) Elevation in m (amsl) Erosivity (t.m/ha) Accelerated erosion
- 7. Location Potential annual soil loss (mt./ha) Land slope (%) 2 4 6 Anuradhapura Galgamuwa Horowpothana Kantale Mahailluppallama Maradankadawala Polonnaruwa 27 26 31 34 25 28 33 52 51 61 66 48 53 64 84 83 99 108 78 87 104 Potential erosion in selected locations of the central dry zone Source: Dharmasena, 1992 Erosion from dry zone agricultural lands can not be over-looked
- 8. Tank Year Capacity (ha.m) Sedimentation Volume (ha.m) % Rate (ha.m/year) Paindikulama Siwalagala Marikaragama 1984 1987 1990 1990 1986 1990 30.2 28.0 25.8 19.9 36.2 35.3 9.7 11.9 14.1 8.6 9.6 10.5 24.3 29.8 35.3 30.2 21.0 22.9 0.73 0.73 0.23 Source: Dharmasena, 1992
- 9. Land slope (%) Spacing (m) Runoff (m3/hr) Bund height (cm) Drain Depth (cm) Top width (cm) < 2 2 – 4 4 – 6 6 – 8 8 - 10 15 10 7 6 5 165 100 75 60 50 30 25 25 20 20 15 10 10 10 10 70 50 50 40 40 Recommendations for soil conservation bunds
- 10. Contour drains Lock & Spill Contour bunds Stone bunds
- 11. Contour cropping Mulching Cover crops Mixed cropping
- 12. Strip cropping Minimum tillage Crop residues Alley cropping
- 13. 1. Rise of groundwater table in upper areas. 2. The excess irrigation water gets stagnant in the lower area. 3. The salinity is developed due to inadequate disposal facilities in drainage canals 4. Lack of adequate drainage within the cultivated fields. 5. Moreover, non adoption of proper land use Udawalawe LB Phase-2 Salinity affected area In 2000: 30% In 2008: 50% Soil salinity – major irrigation schemes
- 14. Land Use Model Cross Section Recommended for RBE – LHG combination Village Forest Fruit Forest Rain-fed/ homestead Irrigated upland Irrigated lowland
- 15. 50 m 60 m 50 m 35 m LAND USE MODEL ALONG CATENA Home Garden Irrigated Upland Farm tract Village road Fruit Forest Village Forest Irrigated Lowland Irrigation canal 35 m
- 16. Main irrigation canal Natural drainage Irrigable land Homestead Other field crops Village forest Main road Village road Farm tract Communal lands Tank Lower Canal Upper Canal Fruit forest gardens Upstream reservation Downstream reservation
- 17. Eye-brow bund and pitcher system Pathaha system Rainwater collecting wells Micro-tank system
- 20. Water pollution and kidney diseases Calcium Fluoride Cadmium Arsenic Mecury
- 21. Use of Agro-chemicals in Sugar Cane Farms: an example from Nicaragua • San Antonio Sugar Mill of Nicaragua Sugar Estates Ltd. • 3251 died from Chronic Renal Insufficiency (CRI) up to 22 March 2009 • 2244 died during 2005 - 2009 • Pesticides used: Hexacinone, Diuron, Tebuthiuron, 2,4-D, Glyphosate, Ametryn, Paraquat, Endosulfan, MCPA ……………
- 22. Name of weedicide Trade names Banned in USA Reason 2,4 - D 5 1984 Cancer, nervous breakdown, water pollution Alachlor 6 - Cancer, nervous breakdown, water pollution, stunt growth, pregnancy problem Diuron 11 1987 Cancer, pregnancy problem, water pollution Glyphosate 38 - nervous breakdown, CKDu MCPA 35 1984 Cancer, water pollution Oxadiazon 1 - Cancer, stunt growth, pregnancy problem Paraquat 3 1986 ?? Propanil 27 1982 Cancer, stunt growth, pregnancy problem
- 23. Name of fungicide Commercial names Banned in USA Reason Captan 3 1994 Cancer, Mancozeb 21 1992 Cancer, stunt growth, pregnancy problem, hormone deficiency Maneb 3 1985 Cancer, stunt growth, pregnancy problem, hormone deficiency
- 24. Name of insecticide Trade names Banned in USA Reason Carbaryl 04 1987 Cancer, nervous breakdown, water pollution Carbofuran 14 1989 Cancer, nervous breakdown, water pollution, stunt growth, pregnancy problem Chloropyrifos 35 1985 Cancer, water pollution, stunt growth, pregnancy problem Diazinon 11 1980 Nervous breakdown Fenobucarb 14 Cancer, water pollution Phenthoate 13 Cancer, stunt growth, pregnancy problem
- 25. Assessment of Traditional rice farming – 2007/08 - Moneragala • Traditional rice varieties; • Use of organic fertilizers (straw, green manure, cow dung, poultry manure, liquid fertilizer etc.); • Management of weeds through tillage, hand weeding and water management; • Management of pest and diseases by timely cultivation, Kem krama (rituals), maintaining biodiversity and using bio-pesticides; and • Management of available water without leading to moisture stress.
- 26. Assessment of Traditional rice farming – 2007/08 - Moneragala Parameter Modern farming Traditional farming EC (mmhos/cm) 0.99 0.06 pH 6.4 6.4 Soil P 10% increase 19% increase Soil K 33 % increase 52% increase Organic matter 10% decrease 8% increase Compaction (penetrometer reading) 1.3 0.7
- 27. Assessment of Traditional rice farming – 2007/08 - Moneragala Parameter Modern farming Traditional farming Machinery cost (Rs./ha) 23,251 27,303 Material cost (Rs./ha) 14,249 7,402 Labour cost (Rs./ha) 63,327 67,015 Total input cost (Rs./ha) 100,827 102,420 Yield (kg/ha) 4,148 3,177 Cost of production (Rs./kg) IFL 24.31 32.24 Cost of production (Rs./ha) EFL 16.47 16.98 Selling price (Rs./kg) 30.00 40.00 Seed productivity 29.6 32.5 Land productivity (Rs./ha) 23,613 24,660 Labour productivity (Rs./day) 664 869 Investment productivity (Rs./Rs.) 1.50 1.52 Net return (Rs./kg) IFL 5.69 7.76 Net return (Rs./kg) EFL 13.53 23.02
- 28. Climate Change & Soil Resource Productivity Climate change Soil productivity decline Deforestation Mis-management of land Mis-practices of agriculture