Sustainable Yield Intensification in Philippine Cassava Systems

Implemented between 2014 and 2018 in the Philippines, the project's objectives are to generate the scientific information required to establish the relationship between nutrient uptake and yield for cassava, and determine the agronomic use efficiency for individual nutrients. This will aid the development of fertilizer recommendations, and establish 4R-consistent nutrient management practices for smallholder growing systems.

The project uses an approach that successively reduces the risk for growers to invest in fertilizers and thereby aids in market development for the industry. The approach consists of 1) analyses of existing data to derive nutrient uptake functions for cassava, 2) completion of the information with data from on-station trials and trials in commercial fields that demonstrate economic viability and validate nutrient uptake functions, and 3) development of a Nutrient Expert^® (NE) Cassava for the Philippines. Therefore we will 1) determine the parameters for internal nutrient efficiency, response to individual nutrients and attainable yields from nutrient omission trials on stations, then 2) verify parameters in trials in farmers’ fields and develop a Beta version of NE Cassava, then 3) use the Beta version to generate fertilizer recommendations for a selected number of farmer’s fields, and 4) examine the field results jointly with stakeholders and refine the models as needed.

Project field implementation started in July 2014. Four sites were set up in Laguna (on-station), Butuan (two, farmers fields) and Isabella (on-station).

Whilst it is known that cassava responds favorably to fertilization, lack of quantitative knowledge on the response to fertilizer and the uncertainty surrounding that response under specific conditions is a major obstacle to development of the market for cassava fertilizers.