Sustainable Yield Intensification in Philippine Cassava Systems

Executive Summary

Cassava is a crop with significant potential for intensification in Southeast Asia with cassava production changing from a traditional food crop to an export oriented industry that responds to strong external market demands for the crop. The cassava production sector delivers into these growing markets by a combination of increasing the area planted, using higher yielding varieties and partly by trying to intensify through improved management. There are regional differences between growers’ strategies. We believe that specifically improved systems management with adequate crop nutrition provides an opportunity for growers to benefit from strong markets. In 2010, Asia produced about one third of the world’s cassava (FAO STATS, 2012). Thailand with 22 million t and Indonesia with 23.9 million t were amongst the world’s top five producers, each with an area close to 1.2 million ha planted to cassava. Vietnam produced about 8.5 million t, Cambodia 4.2 million t, and the Philippines about 2 million t. Potential for increased production exists in Cambodia, the Lao PDR, Vietnam, Myanmar and the Philippines, both for export and internal markets, as local demand for cassava products is expected to grow. In the tropics, cassava root yields are frequently in the range of 5 to 20 t/ha (Fermont et al., 2009; FAO Stats, 2012). Nevertheless, root yields as high as 75–90 t/ha (fresh weight) and 25–30 t/ha (dry weight) are possible under controlled conditions (El-Sharkawy, 2004). The large difference between experimental yields and farmers yields suggests that there is a large yield gap that can be closed by improved management. In fact this is already occurring: in Indonesia over the past 30 years production increased by 60% due to intensification as area planted to cassava declined by 18%.Whilst it is known that cassava responds 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. If it was possible to quantify nutrient demands for commercially attainable yields at any particular site based on uptake values by the crop and soil supply capacity, then it will also be possible to provide a quantitative estimate of the required fertilizer and of the expected returns to investment in such fertilizers. This is precisely the information, which enables growers to invest in fertilizers at relatively low risks. Currently no such reliable nutrient recommendation models exist for cassava. With information about the agronomic efficiency of nutrients to produce cassava biomass and estimated soil nutrient supply, fertilizer recommendations can be derived. IPNI has successfully developed such decision support software called Nutrient Expert^® that generates reliable fertilizer recommendations for growers of maize and wheat. We propose to produce such a Nutrient Expert^® Cassava for the Philippines with the support of Universal Harvester Inc. (UHI) and Uralkali Trading (Gibraltar) Limited Singapore Branch (UKT), and train key extension agents of government and industry organizations to deploy the model for growers. Partners from the University of the Philippines Los Baños (UPLB) will execute the project with scientific oversight provided by IPNI.

Overall Purpose: The overall purpose of this project is to enhance, in a sustainable and ecologically sound manner, the yield and profitability of cassava production systems.

Project Rationale: The project rationale is to provide information and tools that enable growers and fertilizer industry to benefit from strong markets for cassava. The project will therefore facilitate the effective use of production inputs, and improve the soil quality of intensively managed cassava production systems through the use of 4R Nutrient Stewardship consistent management practices.

Objectives and Expected Results

1. To establish one collaborative project for the development of a Nutrient Expert^® Cassava for the Philippines. The project will generate a fertilizer recommendation model for cassava and improved knowledge on crop nutrition for the sustainable intensification of cassava production.

2. To assist potential users in government and agri-businesses to successfully use the developed Nutrient Expert^® Cassava for the Philippines. The project will educate key project participants in the use of Nutrient Expert^® Cassava for the Philippines so that they can train further potential users of the model.

3. To propagate use of a Nutrient Expert^® Cassava for the Philippines for nutrient management aiming at sustainable maximum economic yields. The project will, through its partners, demonstrate the developed Nutrient Expert^® Cassava for the Philippines widely at regional and international conferences, and in field workshops.