Introduction to site-specific nutrient management (SSNM)

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Introduction to site-specific nutrient management
(SSNM)
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Need for an improved approach to nutrient
management for rice

• The need of rice for nutrients
• Can differ from field to field
• Can differ year-to-year because of varying
  climate and growing-season conditions

Fertilizer rates and timing should be adjusted to
location and season-specific needs and conditions
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SSNM A plant-based approach

• SSNM provides an approach for feeding rice with
  nutrients as needed

• Make optimal use of existing nutrients, such as
  from soil, residues, and manures
• Apply N fertilizer at the time and amount
  required by the rice crop
• Apply P and K fertilizers based on crop need, as
  determined through the omission plot technique

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Site-specific nutrient management (SSNM)
1. Establish a yield target the crops total
needs
3. Fill deficit between total needs and
indigenous supply
2. Effectively use existing nutrients
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SSNM A plant-based approach
Feed the plants need for additional nutrients

• Establish a yield target (plants need for
  nutrients)
• Effectively use the indigenous supply of
  nutrients (soil, water, crop residues, and
  manures)
• Apply fertilizer to fill the gap between crop
  need and indigenous supply

• Firmly based on scientific principles of nutrient
  requirements of the crop to achieve high yields

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Nutrient management for rice Match supply to
need

• 1. Apply only a moderate amount of fertilizer N
  within 2 weeks after transplanting or 21 days
  after sowing

• 3. Apply sufficient P and K to overcome
  deficiency and replace nutrient removed with crop
  harvest
• Apply P basal
• Split apply K (50 basal and 50 at panicle
  initiation)

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Source of nutrients taken up by rice

• Soil
• Crop residues and manures
• Irrigation water
• Biological N2 fixation
• Fertilizers

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Source of nutrients taken up by rice
Nitrogen
Potassium
Nutrient needed for yield target
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Source of nutrients taken up by rice
Nitrogen
Potassium
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Source of nutrients taken up by rice
Nitrogen
Potassium
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SSNM aims to increase profit for rice farmers
through

• High yield
• High efficiency of fertilizer use

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Implementing SSNM

• Match early application of N with low initial
  demand of rice for N.
• Dynamically apply N based on leaf color, as a
  measure of plant need for N.
• Determine P and K needs based on crop growth to
  overcome deficiency and replace nutrient removed
  with crop harvest.
• Use existing recommendations for micronutrients.
• Provide principles and guidelines to assist
  decision making by extension and farmers.

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Development and evaluation of site-specific
nutrient management (SSNM) for rice