Too little, too imbalanced: Nutrient supply in smallholder oil palm fields in Indonesia

• Published in: Agricultural systems 2023-08, Vol.210, p.103729, Article 103729
• Main Authors: Lim, Ya Li, Tenorio, Fatima A., Monzon, Juan P., Sugianto, Hendra, Donough, Christopher R., Rahutomo, Suroso, Agus, Fahmuddin, Slingerland, Maja A., Darlan, Nuzul H., Dwiyahreni, Asri A., Farrasati, Rana, Mahmudah, Nurul, Muhamad, Tohirin, Nurdwiansyah, Denni, Palupi, Sandri, Pradiko, Iput, Saleh, Shofia, Syarovy, Muhdan, Wiratmoko, Dhimas, Grassini, Patricio
• Format: Article
• Language: English
• Subjects: Elaeis guineensis; farmers; Fertilizer; fertilizer application; fertilizers; Indonesia; leaves; magnesium; nitrogen; Nutrient balance; nutrient content; nutrient management; Oil palm; phosphorus; plant nutrition; potassium; Smallholder; Yield
• ISSN: 0308-521X; 1873-2267
• DOI: 10.1016/j.agsy.2023.103729

Smallholders account for ca. 40% of oil palm area in Indonesia but average yield remains low. Despite higher overall fertilizer use in Indonesia compared with other Southeast Asian countries, poor plant nutrition has been identified as a major factor explaining yield gaps in smallholder oil palm fields and little is known about the underlying management drivers. To assess nutrient management in smallholder fields and identify entry points to narrow the existing yield gap via improved plant nutrition. We assessed nutrient balances and gaps for nitrogen (N), phosphorous (P), potassium (K), and magnesium (Mg) and inter-relationships between fertilizer use, leaf nutrient concentration, and yield, using data collected from 977 smallholder fields in Indonesia over two years. There was a positive relationship between yield and nutrient rates, especially for potassium (K). Only half of the fields received fertilizer and average nutrient rates in fertilized fields represented 45% (N), 83% (P), 28% (K), and 25% (Mg) of the associated removal with harvested yield. Applied fertilizer was generally rich in N and P, but poor in K and Mg, leading to nutrient imbalances. Additionally, farmers did not follow appropriate practices on fertilizer placement and splits. Improving current fertilizer supply and management is needed to increase smallholder yields and profit. Current agricultural and research programs will benefit from re-orienting efforts to improve nutrient management in oil palm as a pathway to narrow yield gaps in smallholder fields, which, in turn, requires strengthening extension services to fill in knowledge gaps and tune subsidy programs to facilitate farmer access to fertilizer sources more suited to the crop. [Display omitted] •Despite Indonesia is a major consumer of fertilizers, widespread nutrient deficiencies have been reported across independent smallholder oil palm fields.•We diagnosed nutrient management in 977 independent smallholder oil palm fields in terms of rate, source, placement, and split of fertilizer.•We found that nutrient input was insufficient and imbalanced to achieve high yields.•Most farmers did not follow recommended practices on placement of fertilizer and splits.•Improving nutrient management in smallholder fields will require technical assistance and mechanisms to facilitate farmers access to proper fertilizer sources.