Conservation Agriculture concepts and principles

Conservation Agriculture concepts and principles

1. African Conservation Tillage Network By: Peter Kuria 2 nd November 2017 Conservation Agriculture Concepts and Principles

2. Historical perspectives What is Conservation Agriculture (CA)? Terminologies related to CA Application of the CA principles Opportunities for CA systems World adoption trends of CA CA for challenging situations Overall challenges Contents

3. Food Security more urgent in Africa in coming years Global pop. to increase by 33% to 9 billion by 2050 Africa’s to increase by 115%; by 21% in Asia 60% more food worldwide; 100% in Africa Worldwide hunger decreased by 132 million in last 20 years; it increased by 64 million in Africa. Threatening climate change challenges Farming related land resource degradation

4. Easier to double yields in Africa (say from 1.2 to 2.4 tonnes /ha) A 1% increase in cereal yield can lift 2 million people out of poverty Africa has 60% of the global total uncultivated crop land The Question is How? THE GOOD NEWS:

5. Historical Perspectives Ploughing of the virgin lands led to the “Dust Bowls” in the United States in the 1930 40 million hectares destroyed, 2.5 million people migrated

6. What is Conservation Agriculture? Three principles No or minimum soil disturbance Permanent soil cover Crop & cover crop rotations and associations Maximum and sustainable benefits derived when the 3 principles overlap

7. A = Absence of soil tillage : No mechanical soil disturbance B = Cover of the soil : Permanent cover with residues C = Biodiversity: Crop rootation and/or associations More : CA is not only the 3 principles CA SYSTEM CA SYSTEM A B C

8. The 3 CA principles MUST be complimented by GAP enhancers.. (which are however not CA)! Good agronomic practices Timely planting; Proper plant spacing Effective weed control (with and without herbicides) Use of improved external inputs Improved seeds Judicious use of fertilisers and pesticides. No shame. Could be organic CA. Be ready to develop packages Crop – livestock integration. Not a threat to CA. Agro-forestry – fertiliser trees, fodder, fruit, live fences, wind breakers. Mechanization How should farmers be empowered to differentiate effects of CA and of improved inputs

9. Related terminologies Conservation Agriculture (CA) Conservation Farming (CF) Conservation Tillage (CT), Minimum tillage (MT), NT No-tillage (never tilled) Direct-seeding (DS) Direct-seeding on vegetal mulch

10. Why Zero or Minimum Tillage? Tillage or ploughing – is the most time and power consuming operation is avoided, saving costs and time Undisturbed weed seeds remain in the soil without germinating – reducing weeds Ploughing disturbs the soil – making it susceptible to erosion by water and wind; causes plough pans Ploughing releases CO2 contributing to climate change

11. Minimum soil disturbance The “Deceiving” effects of ploughing IMMEDIATE EFFECTS Weeds are controlled Seedbed is prepared Water infiltration improves Soil aeration improves Nutrients are released, availed Incorporation of manure, fertilizers and organic matter Loose soil eroded and nutrients are leached LONG TERM EFFECTS Depleted soil organic matter Damaged soil structure and macro pores Soil flora and fauna disappear Hard/plough pan formation Acute soil water availability and restricted aeration Distortion of pH levels Decline in nutrient availability

12. More tractors needed, but not for ploughing Not to rob our grand children of their future! Not to lose Carbon

13. CA is needed now, in … Adapting to climate change Tillage accelerates decomposition of soil and soil surface organic matter into CO2. No till reduces CO2. emissions CA fosters: carbon sequestration, maintenance of hydrological cycle and biological pest control Although smaller amounts of carbon can be sequestered per hectare (0.05 – 0.2 metric tons ha-1yr-1), with thousands of farmers practising, benefits are huge. BURNING = PLOUGHING

14. When zero “tillage” means plenty

15. … taking advantage of macro porosity W ater infiltrates...

16. Zero till Conventional 35% more infiltration Field soil measurement

17. Tillage effects on water infiltration and ground cover 12 0.8 Moldboard plow 27 1.3 Chisel Plow 48 2.7 No-till Ground cover (%) Water infiltration (mm/minute) Tillage type

18. What equipment for Conservation Agriculture? Hand tools: Jab planter, hoe, stick Oxen ripping Oxen direct seeding Tractor mounted seeder Tractor mounted seeder Highly mechanized Start with what farmers have

19. Let the roots and soil flora and fauna do the work

20. Concepts of Agricultural production and management ( Derpsch and Moriya, 1999) OLD PARADIGM Soil tillage is good for crop production Crop residue is a waste product –burn/bury them with tillage implement Bare soil for months and years is good farm sanitation Focus on soil chemical processes Chemical pest control is the first option Soil erosion is acceptable and unavoidable risk in farming NEW PARADIGM Tillage is not necessary for crop production Crop residues are valuable products and must remain on soil surface as mulch Permanent soil cover is essential Focus on biological soil processes Biological pest control be first option Soil erosion is a symptom that unsuitable methods are being practiced at the source Under new paradigm i.e. sustainable land use e.g. CA ensures ecological, social and economical sustainability.

21. SOIL COVER - the most important principle?? - Soil cover by crop residues (dead plant matter) or imported mulch Soil cover by cover crops Soil cover by living plants – synchronized for all year round production

22. Soil cover by cover crops - Intercropped cover Imported mulch

23. All-year round cover: MAIN AND COVER CROP

24. Why soil cover? More soil organic matter and available nutrients Promotes biological activity- soil organisms (earthworms, insects, rodents, microbes) leading to increased humus (decomposed organic matter) Increased humus leads to soil enrichment & improved soil structure (aggregation/ pores) Increased water infiltration, decreased water evaporation, water (& nutrient) holding capacity

25. Why soil cover? Cushions temperature changes-dampening extremes Better root penetration and crop growth Less soil erosion from both water and wind More– less fluctuating temperatures Less weed pressure

26. Permanent soil cover Maize > Tephrosia relay after 8 months Maize – Canavalia Maize – Lablab You can’t have soil biology without plants as their host.

27. In drylands the more soil cover, the more water infiltration and the less soil and water loss

28. Early crop growth in a mulched soil

29. Imperata cylindrica controlled by Mucuna

30. How Much Residue is Enough? 10 % 30 % 50 % 90 % Source: Purdue University

31. Principle 3 : Rotations and associations

32. Crop Rotations Definition: A planned system of alternating crops aimed at maintaining and improving soil productivity Crop rotations can include commercial and cover crops Produces varying quantities & types of residues Facilitates residue management

33. Crop rotations-principles Basis of a good rotation is alternation of crops: With differing ability to absorb or exhaust nutrients (e.g. from deeper to top soil layers) With different susceptibility to specific diseases Based on considerations of beneficial or detrimental effects of crop on following crop Different peak requirements for inputs such as labour and water

34. Crop rotations - principles Effects on the succeeding crop due to: Moisture Nitrogen and other nutrients Root type and distribution Residue amount for subsequent crop Weeds Pests and diseases Allelopathic toxins Seeding and harvest times

35. Rotational schemes for annual crops

36. Intercropping grain and cover crops Cereals/grasses and legumes Cereals/grasses and oil crops 2-3 or more species, more favourable C/N ratio, spreads out mineralization Common mixes: Millets + sorghum Pigeonpea + sorghum (planted at same time) Millet/sorghum + Crotalaria juncea Millets + Cowpea Maize + Velvet bean (delayed planting of c crop )

37. Crop mixtures: for weed suppression

38. Summary Greater crop production overall Break pests cycles and control weeds by introducing weed smothering combinations Improved nutrient cycling – from deeper layers by trees and shrubs to crop rooting zones Diversification of crops in rotations may mitigate against dry spells and some crop failures Balance amount and quality of residues for soil cover from legumes, cereals, high and low biomass crops

39. Some basic implications

40. Integrated holistic approach ! Management Cover crop Rotations Improved water harvesting and retention Improved nutrient recycling Net accumulation of Soil Organic matter No soil disturbance

41. More roots…

42. Biological activity is restored ; soil fauna is back ...

43. Promote soil biological life, it is the engine room of your soil Soil biota decompose plant residues and promote soil fertility, nutrient cycling, soil structure, water infiltration, water holding capacity, soil aeration, and filters and suppresses soil-borne pathogens and pest organisms of your farm by: Avoiding high application rates of acidulated, salt-based and nitrogenous fertilizers Applying conditioner ( “ smart ” ) fertilizers and other additives that promote, rather than retard, soil life Maintaining good soil aeration

44. Soil pH stabilises … Soil acidification is normalised by: build up of soil organic matter minimum (optimal) use of mineral fertilisers Effects : nutrient availability to plants increase/broaden toxicities eliminated range of crops that can be grown increase soil biodiversity increase/rich

45. Field soil measurement Soil slaking & dispersion When water is added to soil : slaking; the breakdown of aggregates into microaggregates (REVERSIBLE) dispersion; the breakdown of aggregates into the primary soil particles of sand, silt and clay (IRREVERSIBLE)

46. Soil health contains many beneficial organisms better movement of air, water and nutrients more nutrients are available porous soil allows better root development Healthy soil

47. Applicability

48. LABRANZA PÓS COSECHA DE Sweet pepper Cassava CA is applicable to virtually all crops Onions Cucumber Tomato Squash

49. LABRANZA PÓS COSECHA DE CA is applicable in different agroecological situations  Wet or dry areas  Slopes  Rain or irrigated systems

50. Challenges Crop-livestock integration

51. Challenges Weeding

52. Challenges Labour

53. How can we facilitate learning of these facts/benefits to trainers and farmers?

54. Worldwide adoption of Conservation Agriculture 6 thSSource World Congress on Conservation Agriculture, Winnipeg, 22-25 June 2014 slide 2/x USA 36 Canada 18 Australia 17.9 Europe 2 Kazakhstan 2 Africa 1.2 Brazil 32 Conservation Agriculture globally 157 Million ha (~11% of arable cropland) Argentina 27 Paraguay 3 China 6.7 tropical savannah continental, dry temperate, moist temperate, moist continental, dry irrigated smallholder smallholder smallholder arid arid large scale large scale large scale large scale large scale large scale subtropical, dry tropical savannah other LA 2.4 >50% W (40%) 20% 99% 100% West (36%) Russia, Ukraine 5.2 India 1.5 other Asia 0.1 CA adoption expanding at the rate of 9 million ha annually 1.22 million ha in Africa. 65% are smallholders. 19,000 smallholders in East Africa are beneficiaries of South-South Partnership Source: Adapted from Kassam, 2015

55. Worldwide adoption of Conservation Agriculture 6 th World Congress on Conservation Agriculture, Winnipeg, 22-25 June 2014 slide 2/x 100 Dustbowl 1930 2000 1950 US Soil Conservation Service conservation tillage dustbowl Siberia/USSR Faulkner (US) – Fukuoka (Japan) commercial no-till/US first no-till demonstration in Brazil Oldrieve/Zimbabwe adoption Brazil plantio direto na palha experiments in China, Indogangetic Plains New boost: Canada, Australia, Kazakhstan, Russia, China, Finland...; Africa Argentina, Paraguay; 1980 1990 First no-till in the US IITA no-till research 50 Mill. ha History and Adoption of CA 1970 2010 155 mill ha first no-till farmers in USA First WCCA in Madrid Source: Kassam, 2015

56. CA Adoption Studies and Impact Documentation in Africa CA now adopted in more than 20 countries in Africa as core production component of CSA Estimated Cropland under CA in Africa is 2.68 Mha . Area under CA has increased by 447% since 2008/09. > 95% of the farmers are smallholders -1ha Of the land under CA: 30% smallholders, 1% medium, 69% large-scale Some 2.5% of the cropped land is under CA.

57. CA for challenging situations Ameliorate plough pans and soil compaction Support developing physical structures for erosion control Consider Agroforestry Amend soil degradation Others? Pre-conditions to implementation of CA

58. Ameliorate plough pans and soil compaction Sub-soiling Planting basins Biological tillage using cover crops with tap roots: Cajanus cajan , Dolichos lablab,

59. Develop physical structures for erosion control Stone bunds Contour bunds Cut off drains Permanent ridges

60. Permanent wide (2 m) beds

61. Contour bunds

62. Consider Agroforestry Fertiliser trees ( Faidherbia albida , ) Multi-purpose trees for fruits, fuel wood, building materials Live fences Wind breakers

63. Addition of lime or manure Leguminous cover crops Proper drainage Amend soil degradation (low pH, sodic soils, chemical toxicity, )

64. Challenges to CA Change of mindset . Need champions/role models. Crop residues to k eep the soil covered. Crop-livestock integration. Weed control. Researching & contextualizing options. Land tenure Adaption of CA to suit local conditions and needs . CA is Knowledge intensive as opposed to power intensive conventional farming Poorly addressed ecosystem/watershed and external environmental issues (produce markets, value addition, and climate change variability) Enticing commercialization of production (farming as a business). Inconsistencies in Government policy support

65. Brachiaria undersown in maize

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