Medium-term effect of fertilizer, compost, and dolomite on cocoa soil and productivity in Sulawesi, Indonesia

Abstract In Indonesia, management practices that reduce soil fertility could be limiting cocoa ( Theobroma cacao L.) production. To address this, we investigated the effects of fertilizers and organic amendments comprising different combinations NPK + urea, dolomite, manure-based compost on properties productivity. We extended an existing field experiment in South Sulawesi, to assess these treatments’ trees from age 2.9 years 7.4 years. The treatments were first applied 5 months after planting subsequently twice a year. Soil analyses performed before planting, 3 years, finally 7 Productivity was assessed yearly between 3.5 highest yields obtained plots receiving compost, although yield benefits diminished over time. Inorganic fertilizer alone doubled compared control, while with three times control. With dolomite alone, cumulated 4 41% higher than positive effect can potentially attributed (1) physical changes increasing water availability, (2) chemical improvement nutrient (3) biologically, by promoting activity beneficial organisms. application increased pH, Ca, Mg contents. carbon greatly declined composted treatments, even though 10 kg per tree year, probably because low C:N ratio compost. Future studies should formulations inputs explore mechanisms which promotes