Graph prepared by Uphoff for monograph by Louise Buck, David Lee, Thomas Gavin and himself on EcoAgriculture (CIIFAD, 2004; for SANREM CRSP). Sources are from Worldwatch Institute’s data archives.
SRI is often hard to accept because it does not depend on either of the two main strategies that made the Green Revolution possible. It does not require any change in the rice variety used (genotype) or an increase in external inputs. Indeed, the latter can be reduced. SRI methods improve the yields of all rice varieties evaluated so far – modern and traditional, improved and local. The highest yields have been attained with HYVs and hybrid varieties (all SRI yields >15 t/ha), but ‘unimproved’ varieties can give yields in the 6-12 t/ha range when soil has been improved through SRI methods, so give the higher market price for these latter varieties, growing them can be more profitable for farmers.
Picture provided by George Rakotondrabe, Landscape Development Interventions project.
Picture provided by Dr. Rena Perez. These two rice plants are ‘twins’ in that they were planted on the same day in the same nursery from the same seed bag. The one on the right was taken out at 9 days and transplanted into an SRI environment. The one on the left was kept in the flooded nursery until its 52 nd day, when it was taken out for transplanting (in Cuba, transplanting of commonly done between 50 and 55 DAP). The difference in root growth and tillering (5 vs. 42) is spectacular. We think this difference is at least in part attributable to the contributions of soil microorganisms producing phytohormones in the rhizosphere that benefit plant growth and performance.
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.
Figures from a paper presented by Dr. Tao to international rice conference organized by the China National Rice Research Institute for the International Year of Rice and World Food Day, held in Hangzhou, October 15-17, 2004. Dr. Tao has been doing research on SRI since 2001 to evaluate its effects in physiological terms.
This is the most simple description of what SRI entails. Transplanting is not necessary since direct seeding, with the other SRI practices, also produces similarly good results. The principle of SRI is that if transplanting is done , very young seedling should be used, and there should be little or no trauma to the young plant roots. These are often ‘abused’ in transplanting process, being allowed to dry out (desiccate), or are knocked to remove soil, etc.
0908 Strategies and Options for Agriculture in the Context of 21st Century Sustainability
Strategies and Options for Agriculture in the Context of 21st Century Sustainability CSD Inter-governmental Preparatory Meeting February 24, 2009
Things we know about the 21 st century that affect agricultural sustainability : <ul><li>Demand/need for food will grow by ~ 50% by 2050 - given probable increases in population and income + need to reduce hunger in the world </li></ul><ul><li>Arable land per capita will be less - given population growth, conversion for other uses, and land degradation </li></ul><ul><li>Water supply and reliability will be less - given likely changes in climate </li></ul>
Things we know about the 21 st century that affect agricultural sustainability : <ul><li>Climate for agricultural production will generally become more adverse </li></ul><ul><ul><li>Need more resistance to pests/diseases </li></ul></ul><ul><ul><li>Need more tolerance of abiotic stresses </li></ul></ul><ul><li>Costs of energy and petrochemical products are likely to become higher </li></ul><ul><ul><li>Input-dependence will lower farm incomes </li></ul></ul><ul><li>Substantial capital requirements will be a constraint on poverty reduction </li></ul>
These are objective facts and trends -- not matters of ideology They raise serious questions about the sustainability of our present strategy of ‘ modern agriculture ’ This strategy favors production that is: large-scale, mechanized, monocropped (not biodiverse), energy-intensive, input-dependent, ‘thirsty’, and vulnerable to pests and diseases, and to drought, storm damage, etc.
T his strategy -- widely referred to as the Green Revolution -- has been successful in the 20 th century But reasonable questions can be raised about how appropriate this will be for the expected conditions in the 21 st century Can the world feed and sustain its population by doing ‘ more of the same’ ? What do we do for an encore ? Is there any alternative ?
Two Paradigms for Agriculture: <ul><li>‘ Modern Agriculture’ strategy is to: </li></ul><ul><li>(a) Change the genetic potential of plants, and </li></ul><ul><li>(b) Increase the use of external inputs -- more water, more fertilizer and insecticides </li></ul><ul><li>Agroecology (e.g. SRI) makes changes in the management of plants, soil, water & nutrients: </li></ul><ul><ul><li>Promote the growth of root systems , and </li></ul></ul><ul><ul><li>Increase the abundance and diversity of soil organisms to better enlist their benefits - with goal of producing better PHENOTYPES </li></ul></ul>
CAMBODIA: Farmer in Takeo Province: yield of 6.72 tons/ha > 2-3 t/ha
CUBA: two rice plants of same variety (VN 2084) and same age (52 DAP)
MALI: Farmer in the Timbuktu region showing difference between regular and SRI rice plants in 2007 trials SRI yield 8.98 t/ha Control yield 6.7 t/ha
<ul><li>* adjusted to 14% grain moisture content </li></ul>MALI: Rice grain yield for SRI plots, control plots and farmer-practice plots, Goundam circle, Timbuktu region, 2008 SRI Control Plots Farmer Practice Yield t/ha* 9.1 5.49 4.86 Standard Error (SE) 0.24 0.27 0.18 % Change compared to Control Plots + 66 100 - 11 % Change compared to Farmer Practice + 87 + 13 100 Number of Farmers 53 53 60
SRI Was Developed in Madagascar <ul><li>by Fr. Henri de Laulanié in early 1980s after 20 years of working with farmers to develop low-cost methods to reduce hunger & poverty </li></ul><ul><li>Farmers who had gotten 2 tons/ha produced 8 tons w/o new seeds or fertilizer </li></ul><ul><ul><li>Ranomafana National Park </li></ul></ul><ul><li>Same results in an AFD irrig. project on the Haut Plateau </li></ul><ul><li>SRI has been spreading around world since 2000 </li></ul>
Peasant Practice SRA * SRI Area 1994/95 1875.5 4361.9 34.5 1995/96 1501.5 5224.5 88.7 1996/97 1419.0 3296.7 226.7 1997/98 3122.0 2893.8 229.7 1998/99 2768.1 2628.0 542.8 Yield 1994/95 2.02 3.96 8.62 1995/96 1.96 3.41 7.89 1996/97 2.08 3.30 10.68 1997/98 2.84 3.78 8.59 1998/99 2.97 4.61 8.07 Average 2.36 3.77 8.55 Rice Yields on High Plateau in Madagascar, Antsirabe & Ambositra Regions,1994/95-1998/99 Robert Hirsch, La Riziculture Malgache Revisitée: Diagnostic et Perspectives (1993-99) Agence Française de Développement, Antananarivo (Janvier 2000), Annexes 13-14
Status of SRI as of 1999 Madagascar Status of SRI as of 1999: Madagascar
SRI Status Today: Benefits demonstrated in 35 countries of Asia, Africa, and Latin America China, Indonesia, Cambodia, Vietnam, Philippines, Laos, Myanmar, Thailand, Timor Leste; India, Nepal, Bangladesh, Sri Lanka, Pakistan, Bhutan; Iraq, Iran, Afghanistan, Egypt; Gambia, Guinea, Senegal, Sierra Leone, Mali, Benin, Moz., Rwanda, Zambia; Cuba, Peru, Ecuador, Costa Rica, Brazil
SRI LANKA: same rice variety, same irrigation system, and same drought -- conventional rice (left); SRI (right)
VIETNAM: Farmer in D ông Trù village – after typhoon
Reduction in Diseases and Pests Vietnam National IPM Program evaluation based on data from 8 provinces, 2005-06 * Insects/m 2 Spring season Summer season SRI Plots Farmer Plots Differ-ence SRI Plots Farmer Plots Differ-ence Sheath blight 6.7% 18.1% 63.0% 5.2% 19.8% 73.7% Leaf blight -- -- -- 8.6% 36.3% 76.5% Small leaf folder * 63.4 107.7 41.1% 61.8 122.3 49.5% Brown plant hopper * 542 1,440 62.4% 545 3,214 83.0% AVERAGE 55.5% 70.7%
47.9% 34.7% Non-Flooding Rice Farming Technology in Irrigated Paddy Fields Dr. Tao Longxing, China National Rice Research Institute, 2004 Weight of rice plant organs after flowering
Agroecological strategy differs from input-dependent ‘Green Revolution’ <ul><li>Management-oriented approach capitalizes upon (a) existing genetic potentials - also in other crops like wheat, finger millet, sugar cane - and (b) endogenous processes and potentials in soil systems – seeking to mobilize, support and benefit from the life in the soil – N fixation, P solubilization, mycorrhizal fungi, etc. </li></ul>
SRI concepts and methods are being extended to wheat production in India Pictures sent by Madhya Pradesh Rural Livelihoods Program operating in tribal communities in Mandla and Shahdol districts of Madhya Pradesh state, Central India
Finger Millet Intensification (left); regular management of improved variety (center) and of traditional variety (right), India
Sugar cane grown with SRI methods (left) in Andhra Pradesh Reported yields of 125-235 t/ha compared with usual 65 t/ha
IMPACT OF COMPOST USE ON CROP YIELDS IN TIGRAY, ETHIOPIA Sue Edwards, Arefayne Asmelash, Hailu Araya and Tewolde Berhan Gebre Egziabher Food and Agriculture Organization of the United Nations Rome, Italy, December 2007
Average grain and straw yields (kg/ha) for 7 cereal crops, based on the averages for each crop, Tigray, 2000-2006 (s=observations for straw yield; g=observations for grain yield)
Estimated marginal value product of nitrogen fertilizer (Kshs/kg N) conditional on plot soil carbon content (Marenya and Barrett, AJAE, 2009)
Changes in management practices can contribute to: <ul><li>Higher yields – no need to expand area </li></ul><ul><li>Higher factor productivity, esp. from water - more crop per drop </li></ul><ul><li>Lower costs of production and higher household incomes </li></ul><ul><li>Better environmental quality </li></ul><ul><li>More agricultural sustainability </li></ul>
Agroecological strategies <ul><li>Not a solution to all of the challenges in agricultural sector but AE benefits are available now </li></ul><ul><li>Still ‘a work in progress’ -- like CA, based on science and on experience </li></ul><ul><li>Can offer many opportunities to meet needs for food security and income in a sustainable manner </li></ul>