Nelly Anna, together with Evalina Herawati, Novita Anggraini, Jajang Sutiawan, Bagastha Olky Narsiga Bangun, and Lastrisa Desfa Banjarnahor, a research team from Universitas Sumatera Utara (USU), conducted field research in community plantations to determine whether jabon trees (Neolamarckia cadamba) grown alongside coffee plants truly become stunted or produce lower-quality timber, as many farmers have long feared. Jabon is a well-known native Indonesian tree species valued for its rapid growth and versatile timber, which is widely used for plywood, furniture, and packaging materials. Its sap and leaves have also traditionally been utilized for medicinal purposes in various regions.

Through a study entitled "Growth and Wood Physical Properties of Neolamarckia cadamba (Jabon) under Agroforestry System," the researchers evaluated the growth of 161 thirteen-year-old jabon trees planted alongside coffee at a spacing of 3 × 3 meters. This planting pattern represents the agroforestry systems commonly practiced by local communities to integrate forestry and agricultural production sustainably. To examine wood quality in greater detail, three representative trees were felled and analyzed from the base to the top of the stem and from the heartwood to the outer layers. Such extensive fieldwork required considerable time, patience, and precision, reflecting the team's commitment to producing reliable scientific evidence.

The results provide reassuring news for farmers who rely on jabon as an important source of income. At thirteen years of age, the trees in the mixed plantation reached an average height of 18 meters with an average stem diameter of 36 centimeters, demonstrating healthy growth comparable to jabon cultivated in monoculture plantations. Most trees exhibited consistent height and diameter classes, indicating stable and uniform development rather than exceptional performance by only a few individuals. The research site also featured favorable environmental conditions, including a cool climate, sufficient rainfall, and fertile soils commonly found in many community plantations across North Sumatra.

The researchers extended their investigation beyond measuring tree height and diameter by examining the physical properties of the wood itself. They found that the lower sections of the stem contained higher moisture content than the upper sections, while wood density followed the opposite pattern, becoming denser and heavier toward the upper stem. These findings provide valuable information for wood processors and manufacturers by identifying which portions of the stem are better suited for specific applications. Denser wood can be prioritized for products requiring greater strength, while less dense sections remain suitable for products with lower structural demands.

Most importantly, laboratory analyses demonstrated that the wood quality of jabon grown in the agroforestry system remained within the acceptable range for industrial use and was comparable to timber produced from monoculture plantations. These findings directly challenge the long-standing assumption that intercropping coffee with jabon reduces timber quality. The researchers also observed that faster-growing trees tended to produce slightly lighter wood because the wood tissue remained relatively juvenile and had not yet reached the density found in more slowly growing trees. Rather than weakening the study, this observation strengthens the credibility of the findings by providing a realistic explanation for natural variation in wood characteristics.

For farmers, the implications extend well beyond scientific measurements. Growing coffee alongside jabon enables farming households to generate annual income from coffee harvests while simultaneously building long-term savings through timber production, without worrying that the wood will lose its market value at harvest. Such agroforestry systems also help maintain soil moisture and fertility through the complementary root systems of both crops, reducing the risks of erosion and drought. Equally important, farmers can meet future timber demand without clearing additional forest land, since timber production is integrated into the same agricultural landscape.

Published in the Asian Journal of Forestry, this research represents more than an academic contribution. It provides practical scientific evidence that farmers can directly apply when making land management decisions. The dedication of Nelly Anna and her colleagues—carefully examining each section of the stem, measuring every wood sample, and analyzing each dataset—demonstrates how rigorous scientific research can generate tangible benefits for local communities. At a time when forest conservation remains an increasingly urgent challenge, the study offers an encouraging message: farmers do not have to choose between cultivating coffee or producing timber. Both can thrive together in a well-managed agroforestry system, creating sustainable environmental and economic benefits for farming families.