Soil Testing and Plant Analysis for Asian Farmers
Laboratory analysis of soil and leaf samples gives farmers an accurate picture of how much fertilizer is needed
The Value of Soil Testing and Leaf Diagnosis
Soil testing gives farmers valuable information about of the nutrient status of the soil they farm, and how much fertilizer is needed. Leaf diagnosis is another useful tool which helps farmers optimize their fertilizer application programs. In December, FFTC held a training course where government workers in soil and plant analysis were able to discuss with an international team of experienced soil scientists the problems they encounter in using these techniques. They also learned about recent technical developments.
Quick Diagnosis in the Field
Participants showed particular interest in new methods of quick diagnosis of soil fertility status. They were introduced to a small low-cost soil testing kit. This is being mass produced in the Philippines for the use of extension specialists and farmers in the field. Biological indicators are another low-cost source of information about the nutrient status of a crop. One example is the symptom of hollow heart in peanut. This is a simple indicator of soils that are low in boron.
Soil Testing Program for Thai Farmers
Thailand's Department of Land Development has begun a soil improvement and conservation program involving 55,000 volunteer farmers from thousands of villages. These farmers, known as "Dr. Soils", are trained to understand basic soil testing techniques. They act as communicators, disseminating information to their villages about land development. They also tell the Department about the land use problems of local farmers.
They have backup from the staff of the Department. The District "Dr. Soils", who is the chief of the Land Development Unit of the Provincial Land Development Station, gives basic recommendations for crop production and land use. There are also a number of Laboratory "Dr. Soils" who provide a scientific soil testing service, including a mobile laboratory. This soil testing service is free of charge to farmers.
Future FFTC Programs
Differences in analytical results may not always reflect differences between the original samples. There is a widespread problem that different laboratories are using different testing methods, and some results might not be reliable. One useful project suggested in the general discussion was that FFTC might conduct a cross-comparison of soil testing results from laboratories in different countries. Identical samples would be sent out, and the analytical results compared to a standard.
It was also felt to be important that countries in the region develop the use of computer simulations. This would give a higher standard of fertilizer recommendations at a lower cost in rural areas.
Index of Images
Figure 1 DR. Paningbatan from the Philippines Demonstrates the Use of a Low-Cost Soil Testing Kit
