ssnm

Introduction to site-specific Introduction to site-specific nutrient management (SSNM)nutrient management (SSNM)

Need for an improved approach to Need for an improved approach to nutrient management for ricenutrient 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

SSNM: A plant-based approachSSNM: 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

1. Establish a yield target – the crop’s total needs

2. Effectively use existing nutrients

3. Fill deficit between total needs and indigenous supply

Site-specific nutrient Site-specific nutrient management (SSNM)management (SSNM)

Feedingcropneeds!

SSNM: A plant-based approachSSNM: A plant-based approach

• Establish a yield target (plant’s 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

Feed the plant’s need for additional nutrientsFeed the plant’s need for additional nutrients

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

Nutrient management for rice: Nutrient management for rice: “Match supply to need”“Match supply to need”

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

2. Use the LCC to distribute N from 2 weeks after transplanting• Select an N dose and critical LCC value to achieve

high yield and 18 to 25 kg grain yield increase per kg N applied• Achieve 1 ton yield increase with 40 to 55 kg N/ha

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)

Source of nutrients taken up by riceSource of nutrients taken up by rice

• Soil• Crop residues and manures• Irrigation water

• Biological N2 fixation

• Fertilizers

Soil


Nitrogen Potassium

Biological N2 fixation

Irrigation water

Crop residues & manures

Nutrient needed for yield target

Soil


Nitrogen Potassium


Irrigation water


Indigenous nutrient supply

gap


Soil


Nitrogen Potassium

Fertilizer


Irrigation water



SSNM aims to increase profit for SSNM aims to increase profit for rice farmers throughrice farmers through

• High yield• High efficiency of fertilizer use

Implementing SSNMImplementing 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.

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

GBPUAT

TRRISWMRI

IIRR

PhilRice

ZU

MAS

CLRRI

NISF

PTRRC

GAAS

HAU

YUHZAU

BRRI

HUAF

Member from 1994 or 1997

Member from 2001

Affiliated member

PPI/PPICIFASDC IPI

ssnm

Science