The issue on fertilizer effectiveness and plant absorption of macro and micro nutrient relies mainly on the right amount, kind and timing of application of this stimulant in the soil. This concern mainly on the determination of the soil nutrients through soil analysis wherein the use of Minus One Element Technique (MOET) and Leaf Color Chart (LCC) for Nitrogen application is must for rice farmers in this era of scientific farming.
Clark N. Melendres, DA-RFO 6 Agriculturist II and Coordinating Officer for Special Foreign Funded Projects said that farmers should incorporate scientific tools to efficiently use resources and increase rice production.
“The MOET is a simple and practical decision-aid technique that assess nutrient requirement of the rice crop in actual field conditions. This also helps identify what nutrient is/are adequate or lacking in the soil,” Melendres said.
He said that this technique addresses problems on high cost of soil chemical analysis, inaccessibility to test centers in remote areas and high cost of inorganic fertilizers.
The MOET kit consist of seven nutrient formulations labeled as Complete which contains essential elements and six other formulations same as complete but lack or minus the specific nutrient specifically, Nitrogen (N), Phosphorous (P), Potassium (K), Zinc (Zn), Sulfur (S) and Copper (Cu). These fertilizer formulations were then mixed to pots preferably without holes containing soil samples from the rice field.
Melendres stressed that farmers should always remember to decontaminate or wash their hands and tools after mixing each fertilizer formulations with the soil to avoid contamination. Then the pots will be planted with four to five seedlings or pre-germinated seeds and retaining only the two best growing plant per pot seven days after transplanting or sowing. The growth, tillering and biomass of the rice plant in minus one treatment will be observed and compared with that of the Complete treatment 30 to 45 days after planting to come up with results on what macro or micro nutrient is/are lacking in the soil. Fertilizer recommendations are also provided with the kit based on the planting season and desired target yield per hectare.
While the LCC is a cheap, fast and handy field instrument to measure green color intensity of leaf which is related to the plant’s nitrogen content. It is reflected on the chart that the yellowish green (No. 2) represents the lowest nitrogen concentration and the dark green (No. 5) as the highest.
Here, Melendres said that the first LCC reading will be done at 14 days after transplanting using the topmost, fully expanded and healthy leaf at least ten sample plants within the area. Farmer should do the LCC reading between 8:00am and 10:00am and not exposing the instrument to direct sunlight. Reading should be done by placing the middle part of the leaf on top of the LCC’s color strips for comparison.
If more than five out of ten leaves have readings below 4 in transplanted rice and below 3 in direct wet-seeded rice, it is recommended the apply 1 bag Urea/ha during Wet Season (WS) and 1.5 bag/ha during Dry Season (DS). If sulfur is deficient in the soil, farmer may use 2 bags of 21-0-0/ha during WS and 3.5 bags of 21-0-0/ha during DS instead of Urea
Melendres stressed that the same person should take the LCC readings from the first sample plant to the tenth plant every reading. LCC readings should be repeated every seven days until the first flowering stage.
The DA has distributed LCCs to all Municipal Agriculture Offices and encouraged farmers to make use of this tool to assess nitrogen content in their fields. These twin tools were of great help to rice farmers to confirm efficient use of fertilizer in their farms.(JEEOgatis)