The use of litterfall from various land agroecosystems to increase the fertility of the land of community cocoa plantations

Abstract

This study aimed to determine the effect of organic fertilizer application from the litter on increasing soil fertility in various cocoa-based agroecosystems around the Lore Lindu National Park (LLNP). Based on the initial survey, 5 (five) types of agroecosystems were obtained, namely (A) cocoa + mixed wood trees, (B) cocoa + fruit trees, (C) cocoa + teak, (D) cocoa + candlenut, and (E) cocoa + gliricidia. Litter found on the floor or under farmers’ gardens in each type of agroecosystem was made from organic fertilizer. The research was designed in the form of an experiment using a factorial randomized block design method, with the treatment of organic material sources (various types of agroecosystems) as the first factor, and the dose of organic fertilizer as the second factor. Doses tried were 0; 15; 30; 45; 60 Mg.ha-1. The experiment was carried out in a double manner; firstly, the organic material was incubated in a pot without plants; secondly, it was applied to cocoa plant seeds in the pot. Variables measured were aspects of the growth of cocoa seedlings in the pot: plant height, number of leaves, stem diameter, leaf area, chlorophyll content, and seed dry weight. While changes in soil properties were observed in the nursery and incubation media, the measured variables were: pH, C-organic, nutrient content of N, P, and K and CEC. The results showed that organic fertilizer made from the litter of cocoa agroecosystem + mixed wood trees and cocoa fruit + produced better cocoa seedling growth than other agroecosystem types. The difference was caused by changes in some physical and chemical properties of the soil due to organic fertilizer. The plant response model to the dose tried was quadratic with an optimal dose of 15 to 45 Mg.ha-1.