|
Himachal Pradesh
STCR Project
Department of Soil Science HPKV,
Palampur - 176 062 Himachal Pradesh
Tel: 01 894-230382 |
PREREQUISITES
The target yield equations are valid under the
following conditions:
-
In an agro-eco-region, the soils should be similar
for using the target yield equations.
-
The selected targets should neither be too low or
too high and should be within the range of yields of experiments.
-
In case of leguminous crops, the fertilizer N
recommendations should be similar to general recommended dose of the area.
-
The developed equations cannot be extrapolated
except using them within the experimental range of soil available nutrients.
-
Secondary and micronutrients should not be limiting
in the soil. Best management practices are to be followed during the crop
growth.
-
Soil testing is a pre-requisite for estimating the
fertilizer nutrients to be applied as per STCR approach.
-
The recommendations for the desired target equations
for different vegetable crops are preliminary and yet to be tested at the
farmers’ field.
Points to be considered
for making soil test based recommendations for different crops (University
Recommendations)
As per soil test values the status of soil with
respect to the nutrient in question is considered as low, medium or high as per
the table given below:
|
Nutrient |
Categories based on Soil status (kg/ha) |
|
Low |
Medium |
High |
Available N |
<280 |
280-560 |
>560 |
|
Available P |
<10 |
10-25 |
>25 |
|
Available K |
<118 |
118-280 |
>280 |
|
|
|
|
-
The various recommendations supplied for different
crops as per university package of practices are applicable for medium status.
-
If the farmer has got this soil tested and he wants
to follow university recommendations then
-
If the soil test value for particular nutrient is
low as per above table, the recommended dose is to be increased by 25% for
that nutrient
-
If the soil test value falls within the high status
then the dose is to be reduced by 25%
-
If the soil test value falls under medium category
then the dose of nutrient as mentioned for particular crop is to be
recommended.
Example
The university recommendation for wheat is 120 kg
N/ha, 60 kg P2O5/ha and 30 kg K2O/ha Let us suppose the soil status of farmer
for N, P and K is as follows
Available N:150kg/ha
Avaiable P: 30 kg/ha
Available K : 200 kg/ha
From the above table Available N is low,
therefore the final recommendation would be 120*125/100= 150kg N/ha or
150*100/46 kg = 326.08kg Urea/ha= 26.08 kg Urea/bigha In case of P, available P
is high, therefore the final recommendation would be 60*75/100= 45 kg P2O5/ha or
45*100/16=281.25 kg SSP/ha=22.5 kg SSP/bigha Available K is medium, therefore
the final recommendation would be 30 kg K2O/ha or 30*100/60=50 kg MOP/ha=4 kg
MOP/bigha .
If possible give final recommendation for bigha area
instead of hectare by just dividing the final values with 12.5
