How to Use the MOET Kit
We had been mentioning the minus-one element technique or MOET as an effective and cheap method of determining nutrient deficiencies in irrigated and rain, fed ricefields. The results of the MOET become the basis for the kind of fertilizer that must be applied on the rice crop.
It should be kept in mind that as yields increase, native soil nutrients are mined heavily, causing deficiencies of micronutrients that are not often present in most high analysis fertilizers in the market. It is therefore imperative that fertilizers be judiciously applied based mainly on the need of the crop, and on the capacity of soil to store and provide the essential nutrients.
The MOET shows the status of essential nutrients in soils such as nitrogen (N), phosphorus (P), potassium (K), zinc (Zn), sulfur (S) and, copper (Cu). The method simulates actual field condition of a flooded or submerged soil. It is easy to use with fast and reliable results, and does not require sophisticated equipment. In addition, the MOET kit is cheaper than other methods.
The farmer can do the testing right in his field using the same variety to be planted on his field. The water to be used to water the test plants should be the same irrigation water that flows into his rice paddy.
We got permission from Dr. Cezar P. Mamaril, inventor of the MOET kit, to print the instructions on the use of the kit so that the results would be reliable and, hence, would really help the farmers.
Some of the materials that can be used as test pots include gallon-sized plastic containers such as vinegar, soy sauce, fish sauce and mayonnaise, and plastic bottles of drinking water. Plastic pails may be used also if the farmer can spare some cash.
Here’s how to prepare gallon-sized plastic containers:
• Cut the upper portion of the gallon sized plastic containers.
• If the containers are transparent or translucent, paint the outer side with black paint to simulate actual field condition.
• Clay pots and plastic pots can also be used. Wrap the inner sides of the clay pots with black polyethylene plastic bags to avoid contamination of the soil by the clay pots.
Avoid using containers that are made of metals, except stainless steel, to avoid contamination.
Prepare seven containers for each field sample.
COLLECTING FIELD SAMPLES
Collect soil samples randomly from at least 35 points at a depth of 20 cm. Use any 8 in x 2 in PVC pipe, bamboo or trowel to collect field samples to avoid contamination. Avoid using shovels.
Collect approximately 35 kg of wet soil samples. Do this immediately after harvest if the field soil is still wet. Otherwise, sampling should be done at the early stage of land preparation.
If the farm has varying soil fertility levels as shown by the stand of the previous crop, divide the farm into uniform sampling units. Collect soil samples from each sampling unit separately. There should be enough soil samples to fill up the containers per set of test.
Avoid taking soil samples at or near carabao ponds, animal manure or near piles of decomposing matters like rice straws or crop residues.
PREPARATION OF SOIL SAMPLES AND TEST POTS
Place the sample in a plastic pail or container that is big enough to accommodate it. The sample should remain saturated with a thin layer of water.
When the soil is dry during sampling, submerge it for two weeks before transferring it to the test pots.
Mix the soil sample thoroughly and remove plant roots and other organic debris. Transfer approximately 4 kg of wet soil into each of the seven test pots.
Transfer the soil inside the test pot into a bigger container. Using your hands, mix the fertilizer formulations separately with the soil in each pot. After mixing a soil sample, return it into its test pot. Make sure that no soil will be left in your hands. You need to wash your hands after mixing and returning a soil sample into its test pot.
Label the pots with corresponding formulations applied in each of them such as Complete, minus Nitrogen, minus Phosphorus, minus Potassium, minus Sulfur, minus Zinc, and minus Copper. The treatment with complete formulation means that all the essential nutrients are included; minus Nitrogen (- N), all nutrients are present except nitrogen; minus Phosphorus (- P), all nutrients except phosphorus are included; minus Potassium (- K), all nutrients are present except potassium; minus Sulfur (- S), all nutrients are present except sulfur; minus Zinc (- Zn), all nutrients are present except zinc; and minus Copper (- Cu), all nutrients are present except copper.
TRANSPLANTING AND CARE OF PLANTS
Transplant at least 5 12-day-old seedlings per test pot or sow at least 6 pre-germinated seeds.
Keep the soil wet but without standing water until the plants are well established. Water plants using irrigation water from the field.
After 10 days, retain only the two best growing plants in each pot. Ensure that the pots are watered. Leave them with standing water with a depth of at least 2 cm. Never allow the soil to dry up.
Grow the plants up to 45 days after transplanting or 55 days after sowing for pre-germinated seeds. Starting on the 14th day after transplanting, observe the growth of the rice plants.
OBSERVATIONS TO BE MADE
Compare the growth of the plants in each test pot with the plant treated with complete fertilizer formulation. The one with complete fertilizer formulation should be normally healthy.
If the growth of the plants in the rest of the pots would be as healthy as the plant with complete treatment, then the soil has no nutrient deficiency.
Count the number of tillers. If the tiller count of each pot is 80 percent or less than the plant with complete treatment, then the nutrient indicated on the pot is deficient.
If a weighing scale is available, cut the plants at the base close to the surface of the soil and compare the weights of the plants from each of the pot with the plant with complete treatment. If the weight of any of the treatments is less than 80 percent of the complete treatment, then the nutrient represented by the label of the pot is deficient.
The instruction booklet inside each kit indicates the kind and amount of fertilizer that must be applied for each deficient element.