2. WHAT IS SSNM
SSNM is a plant based apporach for managing the
nutrients reguirements of a crop .It provides principles
and tools for supplying the crop nutrients as and when
needed to achieve high yeilds while optimizing use of
nutrients from indegenious sources.
PRINCIPLES OF SSNM
(i) Increased yields per unit of applied
fertilizer.
(ii) Decrease the losses of fertilizer
(iii) Reduced disease and insect damage.
3.
4. STEPS IN USE OF SSNM
Step 1: Establish an attainable yield target
Step 2: Effectively use existing nutrients
Step 3: Apply fertilizer to fill the deficit
between crop needs and indigenous
supply
5. METHODS OF SSNM:
1.Nutrient omission plot technique
2. LCC
3. SPAD
4. STCR
5. Computer based tools/models –
Decision support
6. 1. NUTRIENT OMISSION PLOT
TECHNIQUE:
•With Nutrient omission plot technique, one plot of rice is
grown with abundant fertilizer supplements (NPK plot or
NPK plus micronutrient plot) and the yield thus achieved
is used to calculate the full demand of crop for P and K
7. 2. USING THE LEAF
COLOR CHART (LCC) TO
MANAGE NITROGEN
That can help farmers determine the right time to apply
nitrogen (N) to the crops. LCC is mainly using in rice, wheat
and maize to management N requirements.
How to use the LCC? (Example: rice)
1Select plants for testing
2. Match the leaf to the chart:
3. Measure the leaf color
4. Determine the average LCC
8.
9. 3. SOIL PLANT ANALYSIS
DEVELOPMENT (SPAD)
The SPAD meter is a simple portable diagnostic tool
used for monitoring crop N status in situ in the field. To
achieve the maximum yield target, the N concentration of
the upper most fully expanded leaf must be maintained
at or above 1.4 g N/m2 (leaf area basis)
10. 4. SOIL TEST CROP RESPONSE
(STCR)
The approach has many limitations and its validity
under field conditions has always been questioned.
Currently, the targeted yield approach has become the
mainstay of coordinated Soil Test Crop Response
(STCR)
AICRP on STCR in 1967 and the STCR concept was
developed by Ramamoorthy, in 1987.
