Importance ofPot Culture and Field Trials of Soil Test
Importance of Pot Culture and Field Trials of Soil Test
Importance of Pot Culture:
The ultimate objectives of interpretation studies are to establish relationships between laboratory results and crop response in the field. The use of potted plant studies to complement necessary laboratory and field trails can expedite the job. Potted plant study provide estimates of nutrients availability to plant in the soil samples tested in the laboratory with all soil exposed to the same environmental conditions, during cropping period. Careful controlled pot experiment should precede field trials whenever possible.
Recommended practices for increasing crop production must be valid under field conditions. Therefore, field trials must be conducted to confirm the information gained in the laboratory and glass house.
The objective of field trials in interpretation studies are two folds.
1. To confirm or adjust previously determined nutrient element critical level.
2. To obtain fertilizer response data required for economic interpretation.
T.O general approaches are possible to field experimentation to achieve these objectives.
The most widely used approach is to conduct field trails on a large number of fields representing a wide range of nutrient levels on major soil types in a region. It has the strong advantage that relationships between soil nutrient level and crop response can be verified under the widely diverse climatic, soil and management conditions. Supervision of large number of trails located over an area is often difficult and uncontrollable variations create problems in evaluation of results.
A second approach to obtaining the necessary field data is to attempt to establish fertility gradient within the field for study of relationship between soil nutrient levels and crop responses to fertilizer application. This approach has been taken in the All India Co-ordinate Scheme for investigation on Soil Test Crop Correlation. It has the advantages that variations in influencing factors other than fertility can be minimized and that more detailed investigation with closer supervision are possible due to smaller number of locations involved.