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0417 Why and How 21st Century's Agriculture Should be Different from 20th Century Agriculture
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0417 Why and How 21st Century's Agriculture Should be Different from 20th Century Agriculture


Presented by: Norman Uphoff …

Presented by: Norman Uphoff

Presented at: Rice Experimental Station, INCA, Los Palacios

Published in Technology , Business
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  • This figure is from research from the China National Rice Research Institute reported at the Sanya conference in April 2002 and published in the Proceedings. Two different rice varieties were used with SRI and conventional (CK) methods. The second responded more positively to the methods in terms of leaf area and dry matter as measured at different elevations, but there was a very obvious difference in the phenotypes produced from the first variety's genome by changing cultivation methods from conventional to SRI.
  • This picture was contributed from Cambodia by Koma Yang Saing (CEDAC). Viewers should try to imagine the very small single young seedling from which this massive plant grew.
  • Picture provided by Gamini Batuwitage, Sri Lanka, of field that yielded 17 t/ha in 2000.
  • This picture from Sri Lanka shows two fields having the same soil, climate and irrigation access, during a drought period. On the left, the rice grown with conventional practices, with continuous flooding from the time of transplanting, has a shallower root system that cannot withstand water stress. On the right, SRI rice receiving less water during its growth has deeper rooting, and thus it can continue to thrive during the drought. Farmers in Sri Lanka are coming to accept SRI in part because it reduces their risk of crop failure during drought.
  • These data from a study done by Fide Raobelison under the supervision of Prof. Robert Randriamiharisoa at Beforona station in Madagascar, and reported in Prof. Robert's paper in the Sanya conference proceedings, give the first direct evidence to support our thinking about the contribution of soil microbes to the super-yields achieved with SRI methods. The bacterium Azospirillum was studied as an "indicator species" presumably reflecting overall levels of microbial populations and activity in and around the plant roots. Somewhat surprisingly, there was no significant difference in Azospirillum populations in the rhizosphere. But there were huge differences in the counts of Azospirillum in the roots themselves according to soil types (clay vs. loam) and cultivation practices (traditional vs. SRI) and nutrient amendments (none vs. NPK vs. compost). NPK amendments with SRI produce very good results, a yield on clay soil five times higher than traditional methods with no amendments. But compost used with SRI gives a six times higher yield. The NPK increases Azospirillum (and other) populations, but most/much of the N that produced a 9 t/ha yield is coming from inorganic sources compared to the higher 10.5 t/ha yield with compost that depends entirely on organic N. On poorer soil, SRI methods do not have much effect, but when enriched with compost, even this poor soil can give a huge increase in production, attributable to the largest of the increases in microbial activity in the roots. At least, this is how we interpret these findings. Similar research should be repeated many times, with different soils, varieties and climates. We consider these findings significant because they mirror results we have seen in other carefully measured SRI results such as the Anjomakely factorial trials (Slide 24) and the previous season's trials with SRI at Beforona (10.2 t/ha).


  • 1. Why and How 21st Century Agriculture Should Be Different from 20th Century Agriculture Rice Experimental Station, INCA, Los Palacios, Cuba July 9, 2004 Norman Uphoff Cornell International Institute for Food, Agriculture and Development (CIIFAD)
  • 2. 20th Century ‘Modern’ Agriculture Has Been the Most Successful in History
    • Per capita food production , 1960-2000, increased by 30%
    • Real food prices in constant terms decreased during this period by 48%
    • Agriculture was an ‘ engine of growth ’ worldwide for over four decades
    • Industry was supported by capital and labor generated/released by agriculture
  • 3.  
  • 4. However, ‘modern agriculture’ is not necessarily the final development
    • Productivity gains achieved with heavy use of external inputs are slowing down
    • Negative side-effects are becoming more evident -- environmental, social costs
    • Can we make further progress in the 21st century by doing ‘ more of the same ’?
    • Doubtful because of diminishing returns -- in cas of rice (K. Cassman et al., 1998) -- a further 60% increase in rice production we will require 300% increase in N fertilizer
  • 5.  
  • 6. We Need to Raise the Productivity of LAND -- becoming scarcer per capita
    • WATER is becoming scarcer , at least for agricultural uses - and certainly scarcer per capita and in per area terms -- lower water quality is also a growing concern
    • Raising the productivity of LABOR is the key to national development and to reducing poverty
    • Can we do this environmentally friendly ways ? SICA experience says YES ( SI )
  • 7. Previous Productivity Gains Were Made in Large Part with Use of CHEMICAL INPUTS
    • F ertilizers, pesticides, insecticides, fungicides, herbicides, etc. are now
    • -- giving diminishing returns while -- creating environmental hazards and health risks ,
      • with rising costs of production and
    • -- continuing problems of efficacy
  • 8. Changes in Fertilizer Use
    • World Grain Fertilizer Marginal
    • Production Use Response
    • (mmt) (mmt) Ratio
    • Decade  Decade 
    • 1950 631 --- 14 --- --
    • 1961 805 (+174) 31 (+17) 10.2:1
    • 1969-71 1116 (+311) 68 (+37) 8.4:1
    • 1979-81 1442 (+326) 116 (+48) 6.7:1
    • 1989-91 1732 (+290) 140 (+24) 12.1:1
    • 1999-01 1885 (+153) 138 (-2)  ?
  • 9.  
  • 10. Problems with Agrochemicals
    • Rising Costs due to supply-demand dynamics for petroleum in future, also end to govt. subsidies?
    • Environmental and Health Hazards are becoming more evident
    • Uncertain Efficacy – chemical treadmill caused by resistance to chemicals -- ‘run just to stay in place’
    • US pesticide use up 14x since 1950, as crop losses increased from 7% to 13%
  • 11.  
  • 12. 21st Century Agriculture Should Be
    • More PRODUCTIVE in terms of :
      • LAND -- per unit area -- per ha or per acre
      • LABOR -- per hour or per day
      • WATER -- per cubic meter or per acre/ft
      • CAPITAL -- more profitable for investment
      • More robust in face of CLIMATE CHANGE
      • ACCESSIBLE to the poor, reducing poverty
      • Providing greater FOOD SECURITY
      • Contributing more to HUMAN HEALTH
  • 13. These expectations call for a
    • ‘ Post-Modern’ Agriculture
    • one that is more productive and profitable , while being more environmentally benign and more socially beneficial , i.e., a Green er Revolution
  • 14. Post-Modern Agriculture
    • Is not like ‘post-modernism’ in literature and humanities; doesn’t reject ‘modernity’
    • P-M agriculture builds on same scientific foundations as does modern agriculture
    • It will be more fundamentally grounded in biological science than current agriculture
    • Biotechnology is part of P-M agriculture but agroecology is its basic foundation
    • Post-modern agriculture not ‘backward’ -- in fact, it is the most modern agriculture
  • 15. 20th Century Agriculture
    • Built on advances made in engineering starting in 18th century -- farm implements and equipment, powered machinery
    • Also on knowledge from chemistry from middle of 19th century - esp. fertilizers
    • 20th century accelerated improvements made in genetic potentials thru breeding
    • The basic approach was to increase and improve the INPUTS made in agriculture
    • Modern agriculture is ENERGY-intensive -- reducing/displacing labor at expense of land
  • 16. ‘ The Green Revolution’ Is Reaching Certain Limits
    • Productivity gains are decreasing -- slowdown in yield increases since end of 1980s
    • Diminishing returns to fertilizer and other inputs are raising farmers’ costs of production -- evident decline in the productivity of inputs
    • Costs of inputs are rising as subsidies are cut; petroleum prices are likely to rise in future
    • Water availability for agriculture is diminishing -- we need less ‘thirsty’ methods of production
    • Adverse impacts on environment and human health are rising -- agrochemicals  , water quality 
  • 17. ‘ Modern Agriculture’ Is Not Sustainable
    • Fortunately, there are alternatives that are
    • Scientifically sound , not just fads or fancy
    • Environmentally benign , or even enhancing
    • Profitable over time, some even immediately
    • Employment-generating for social welfare
    • More beneficial for human health
    • Useable at various scales of production , and
    • Continually evolving and improving
      • as more becomes known about them, and
      • as more farmers and researchers work with them
  • 18. Modern Agriculture and Biotechnology Have Become Overly ‘Genocentric’
    • Productivity and success in agriculture depend equally on THREE major factors:
    • GENETIC POTENTIAL -- the starting point
    • INPUTS -- from farmers and environment
    • MANAGEMENT -- by farmers to get best results from inputs and to deal with the environment, to create the best fit among genetic potential, inputs and environment -- do not overemphasize genetics
  • 19. Example of the System of Rice Intensification (SRI)
    • Yield increases of 50-100% or more:
    • Without changing varieties
    • Without requiring chemical inputs (fertilizer and pesticides - not needed)
    • Using about 50% as much water and only 10-20% as much seed
    • Also get higher grain quality
    • Get more productive PHENOTYPES by changing management practices
  • 20. SRI is a Matter of POTENTIAL
    • Potential already existing in genome
    • Do not get same results every time because this is biology, not industry
    • Biology gives widely varying results -- SRI = E in the G x E equation
    • Not same results every time -- look to soil and not just to genes (only potential)
    • SRI has potential to change agriculture in the 21st century, because of what we are learning from it
  • 21. SRI demonstrates when RICE PLANTS GROW BEST
    • (A) Their ROOTS grow larger and deeper when the plants have been
    • transplanted carefully , without trauma, [tho’ direct seeding is option] , and there is
    • wider spacing between plants, giving canopies and roots more room and light
    • (B) They grow better in SOIL that is kept
    • well aerated , with abundant and diverse
    • soil microbial populations and fauna
  • 22. Plant Physical Structure and Light Intensity Distribution at Heading Stage (CNRRI Research --Tao et al. 2002)
  • 23. Single Cambodian rice plant transplanted at 10 days
  • 24.  
  • 25. SRI field in Sri Lanka -- yield of 13 t/ha with panicles having 400+ grains
  • 26.  
  • 27. Rice field at CPA Camilo Cienfuegos in Cuba -- 14 t/ha
  • 28. Two rice plants in Cuba -- Same variety: 2084 (Bollito) Same age: 52 DAP
  • 29. Single SRI Rice Plant Grown at Rice Research Station, Maruteru, AP, India
  • 30. Rice Roots - Andhra Pradesh, India - SRI on right
  • 31. Two rice fields in Sri Lanka -- same variety, same irrigation system, and same drought : conventional methods (left), SRI (right)
  • 32. Agroecological Understanding
    • A different view of SOIL, stressing its life and its health -- do not regard soil as an inert repository for seeds, fertilizer, etc.
    • An appreciation of MICROORGANISMS and other SOIL BIOTA -- as creators and maintainers of soil fertility -- performing many functions for plant growth/health
    • Greater attention is paid to plant ROOTS as the foundation for agricultural success
    • Plants and soil organisms have coevolved for several hundred million years
  • 33. Modern Agriculture and Biotechnology Focus on One Species at a Time
    • This ignores the all-important CONTEXT of interactions among plants , among soil organisms , between plants and soil organisms , and of these with animals
    • AGROECOLOGY captures the benefits of synergy among these various organisms, capitalizing on the potentials of their existing genomes as they interact with their environments to produce phenotypes
    • (A) GREEN REVOLUTION - to raise yields:
    • Change genotype to make organisms more responsive to increased inputs
    • Provide more inputs
    • (B) SRI - neither of these is necessary, just:
    • Increase the growth of root systems , and
    • Promote more abundant and diverse soil microbial populations and fauna
  • 35. Root Activity in SRI and Conventionally-Grown Rice Nanjing Agricultural University (Wang et al. 2002) Wuxianggeng-9 variety
  • 36.  
    • LESS CAN PRODUCE MORE by utilizing the potentials and dynamics of biology :
    • Smaller, younger seedlings become larger, more productive mature plants
    • Fewer plants per hill and per m 2 can give more yield under SRI growing conditions
    • Half the water can give a greater yield and
    • Increased output is achieved with fewer or no external inputs -- “feed the soil > plant”
    • Get new phenotypes from existing genotypes
  • 38. The contributions of soil microbial activity need to be taken more seriously
    • “ The microbial flora causes a large number of biochemical changes in the soil that largely determine the fertility of the soil.” (DeDatta, 1981, p. 60, emphasis added)
  • 39. Soil biological contributions
    • Biological N fixation (BNF)
    • P solubilization (also other nutrients)
    • Mycorrhizal fungi (water and nutrients)
    • Protozoan ‘grazing’
    • Phytohormone production
    • Plant protection (induced systemic resistance, etc.)
    • Other biological functions ???
  • 40. Need NEW PARADIGM for agriculture in 21st century
    • Biologically based and driven -- less tied to ‘industrial’ models of agriculture
    • Ecological perspective -- not one species at a time (agroecology)
    • Less dependent on external inputs, benefit from biological processes
    • Farmer participation part of process of innovation (partners > beneficiaries)