Designing a Decision-Support Tool for Fertilizer Recommendations in Oil Palm Smallholders

Authors

Rana Farrasati, University of Nebraska-LincolnFollow

First Advisor

Patricio Grassini

Committee Members

Haishun Yang, Laila Puntel

Date of this Version

11-2024

Document Type

Thesis

Citation

A thesis submitted to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Agronomy

Under the supervision of Professor Patricio Grassini

Lincoln, Nebraska, November 2024

Comments

Copyright 2024, Rana Farrasati. Used by permission

Abstract

Oil palm (Elaeis guineensis Jacq.), originally from West Africa, now accounts for 42% of global vegetable oil production and mainly includes key regions cultivated in tropical regions of Southeast Asia, West Africa, South America, and Central America. Despite its economic significance, the oil palm industry faces challenges of stagnant yields and large yield gaps, particularly among independent smallholders. These issues often stem from inadequate nutrient management practices and limited agronomic knowledge. Our objective was to quantify nutrient requirements for mature oil palm plantations as a basis to design a decision support tool (DST) for fertilizer recommendations. To do so, we investigated relationships between yield and nutrient accumulation and removal using a large database collected from oil palm plantations in Southeast Asia and West Africa (n = 669 observations) and derived requirements for nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg). We found robust relationships between yield and nutrient accumulation and estimated that 5 (N), 0.5 (P), 6 (K), and 0.7 (Mg) kg per Mg of FFB are required for plantations targeting 75% of their yield potential. Based on these findings, we designed a DST that provides site-specific fertilizer recommendations for smallholders based on yield level and available fertilizer sources, requiring a minimum set of data inputs. Implementation of the tool has the potential to narrow the current yield gap and promote sustainable intensification, ultimately supporting economic growth and improving smallholder livelihoods.

Advisor: Patricio Grassini