Influence of soil organic carbon on rice biomass allocation in agroecosystem area, Tuban, East Java

¹ Biology Department, Institut Teknologi Sepuluh Nopember, Surabaya, Indonesia
² Faculty of Agronomy, University of Agriculture and Forestry, Hue University, Vietnam

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it. ; This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Rice (Oryza sativa L.) serves as Indonesia’s primary staple crop, with its productivity closely linked to soil fertility parameters, particularly organic carbon content. This study investigates the correlation between soil organic carbon levels and biomass distribution (aboveground and belowground) in rice plants across three agroecosystem areas in Tuban Regency: Jenu, Palang, and Plumpang. Biomass measurements included aboveground and belowground components, along with root-to-shoot ratios. Jenu, with the highest organic carbon content (4.538%), exhibited the greatest total biomass (134.13 g), comprising 95.06 g shoots and 39.07 g roots, and an R:S ratio of 1:2.4. Palang, with low organic carbon (0.434%), yielded 80.23 g biomass (62.16 g shoots, 18.07 g roots) and an R:S ratio of 1:3.4. Plumpang, with moderate organic carbon (1.328%), produced 57.73 g biomass (48.73 g shoots, 9 g roots) and an R:S ratio of 1:5.4. The relatively balanced biomass allocation in Jenu suggests that elevated soil organic carbon enhances both shoot and root development. Correlation analysis confirmed significant positive relationships between organic carbon and shoot biomass (r = 0.797; p = 0.010), root biomass (r = 0.853; p = 0.003), and R:S ratio (r = 0.763; p = 0.017). These findings underscore the critical role of organic carbon in optimizing biomass partitioning and improving rice productivity, highlighting the need for soil management strategies that prioritize organic matter enrichment.