Is SRI in Conflict with

1
Is SRI in Conflict with Conventional Wisdom?

• P. Kishan Rao

2
There have been claims and counter claims about
the scientific basis of SRI and its performance
on both research farms and farmers rice fields.
This paper asks some probing questions on the
idea, concept and practices of SRI vis-à-vis
conventional rice cultivation as understood and
experienced by the scientists and farmers at
different times.
3
Land

• Any and every land is suitable for SRI provided
  it fulfills two conditions
• The land in question should be part of a
  stabilized rice eco-system.
• The land area should be limited to the
  proportionate availability of compost.

4
Dichpali Experiment (1933)

• No. 1
  Plot No. 2 Plot No. 3 Plot
• Amount of land measured for the
• contrast. All portions had the same
• cultivation                   6,394 sq.
  ft.  6,394 sq. ft.   6,394 sq. ft.
• Amount of seed sown. All the seed
• sown was the same quality   6
  lb.               6 lb.                      6
  lb.
• Amount of rice taken in each case
• by measure, not weight      422
  lb.            236 lb.                     60 lb.
  
• Amount of straw in similar
• sized bundles                 138
  bundles     106 bundles        40 bundles
• Note that No.1 Plot had 1.25 to 1.5 inches
  compost No.2 Plot had some farm rubbish plus 3/8
  inch of Indore compost and No.3 Plot was the
  control and had no nutrient amendments (2.2 lb1
  kg)
• Source Howard, An Agricultural Testament, 1938

5
Tilling
6
Tilling

• The store of nitrogen in the soil in the form of
  organic matter has to be carefully conserved it
  is part of the cultivator's working capital.
• Too much cultivation and deep ploughing will
  oxidize this reserve and the balance of soil
  fertility will soon be destroyed. (Howard, 1938,
  p. 8)

7
Water

• If the field is located in an area with assured
  water supply throughout the crop period, then the
  farmer/s should be capable of controlling the
  supply of water and its drainage at all times

8
Timing

• For any particular agro-climatic zone, there is
  always a short time band that is ideal time for
  cultivating rice
• Experience has shown that a much delayed
  transplanting of SRI has yielded more than the
  conventional paddy with all other conditions
  being the same

9
Seed 1) Direct Seeding

• My rice, on the other hand, was grown in
  accordance with the natural life cycle of the
  rice plant, just as though it were growing wild.
  I wait patiently for the plant to develop and
  mature at its own pace. (Fukuoka, 1978, p. 56)

10
Seed 2) Seedbed Method

• Wherever possible, seedbed can be prepared with
  sand and compost as this method has distinct
  advantages over soil and compost combination for
  handling the young seedlings

11
Land Preparation

• Wherever possible, puddling and deep ploughing
  should be avoided, and the tilling depth should
  be limited to around 4 (10 cm)

12
TransplantationTraditional
13
Transplantation SRI

• The ideal time for transplantation is when the
  seedling has two leaves
• From IRRI Media Summary Transplanting rice
  seedlings as early as possible can significantly
  increase grain yield in irrigated areas(Estela
  Pasuquin et al., in Crop Science
  http//www.cropscience.org.au/icsc2004)

14
Fertilisers/Manures

• During the green revolution era, the
  introduction of chemical fertilizers in
  combination with high-yielding dwarf varieties
  with more and more areas having assured
  irrigation added year after year increased
  productivity and production substantially.
  Presently those yields are no more maintainable
  even with addition of large quantity of
  fertilizers

15
Irrigation

• Rice plants grow best when the water content in
  the soil is between 60 to 80 percent of its
  water-holding capacity. When the field is not
  flooded plants develop stronger roots and are
  extremely resistant to attacks by disease and
  insects. (Fukuoka, 1978, p. 54)

16
Diseases

• As the overwhelming majority of chemical
  pesticides are nitrogenous and often chlorinated
  these, in turn, create a situation that is
  unfavourable for the plants resistance
  (F. Chaboussou, 2004, p.
  208)

17
Weedicides

• Unlike in conventional rice cultivation, in SRI,
  weeds are considered as a challenge and more of
  an opportunity of providing the much-needed
  organic matter in the form of green mulch which
  is essential for building strength and disease
  resistance as well. Application of weedicides
  negates these benefits and, on the other hand,
  makes the rice plant vulnerable

18
Tillering/Root Intensification

• A single plant (whether transplanted or directly
  sown) is eminently capable of producing more
  tillers and root volume under near-saturated
  conditions, and consequently more grains per unit
  area of soil.
• Understandable in terms of the Katayama Tillering
  Principle

19
Mechanical/Hand Weeding

• The idea behind weeding in conventional rice
  cultivation is to provide the rice plants
  unhindered access to all the nutrients, both
  natural and artificially provided, by clearing
  the weeds from time to time.
• SRI takes up this idea in earnest and leads to
  its logical conclusion by converting a menace
  into an opportunity for providing crop nutrition.
  The weeding activity also results in aeration to
  the roots that is otherwise improbable in
  submerged conditions

20
The Pragmatic Approach

• The scientific community and the farming
  community the world over may well come together
  in solving the problems of water shortages, soil
  degeneration and growing hunger and, in a spirit
  of cooperation and brotherhood, they should work
  for the common good of all living beings

21
Conclusion

• The cultivation of rice has recently been going
  through a complete metamorphosis in so far as the
  principles underlying its practices and,
  eventual, grain yields.
• SRI is one such activity that has forced
  scientists and farmers alike to have a
  re-look at the whole gamut of issues ranging from
  food production and resource conservation to also
  ecological, ethical and environmental
  considerations

22
SRI is, as a catalyst, bringing about a change
for better and helping validate what is
Conventional Wisdom.
23
Thank You

• Kishan Rao
  Parcha