Optimizing use of soil nutrient sources for rice

MANILA, Philippines - Rice experts are urging farmers to optimize the use of indigenous nutrient sources like crop residues and manures as well as time the application of fertilizers to meet the deficit between rice demand for nutrients and the supply of nutrients from the soil and organic inputs to increase rice yields.

This crop management approach, called the SSNM (Site-Specific Nutrient Management) technique, stresses that nutrient management should be based on specific location, crop needs, and season since soil condition varies from one farmland to another. 

The Irrigated Rice Research Consortium in Asia has noted that on the average, the SSNM increased yields and gross income by seven percent in four years. Here in the Philippines, yields ranged from five tons to nine tons a hectare.

At PhilRice (Philippine Rice Research Institute), study leader Hermenigildo Gines said farmers can expect higher yields with timely application of fertilizer to solve nutrient deficiency. He added that all the farmers need to do are to identify the needed nutrients, set a target yield, and apply the fertilizer that is deficient in the soil. 

Before setting a target yield, Gines said farmers need to determine the nutrients available in the soil through the minus one element technique (MOET) or the nutrient omission plot technique (NOPT).

Although the NOPT determines the natural capacity of the soil, water and other materials like manures and crop biomass to provide nutrients for the rice plant, it takes a whole season before results are known. Thus, farmers may use of the MOET (minus-one element technique) instead as it is completed in a much shorter time.

The MOET shows the status of nitrogen, phosphorus, potassium, sulfur, copper and zinc in the soil under flooded or submerged condition. It is farmer-friendly, does not require sophisticated equipment, can be done right in farmers’ fields, and is easy to use with fast and reliable results. The kit costs much cheaper than other methods.

PhilRice soil expert Wilfredo Collado said SSNM ensures higher productivity even at a minimum target yield of 5 t/ha if farmers follow the management practices specifically recommended for their respective field conditions. – S.Ma. Pablico and M.G. Layaoen