Tropical Soil Science

Site characterization

Study 07

Baseline reported in thesis

Study ID: CHRS 07

Research question

What soil conditions define the starting point for field comparisons?

Location and scope: Puerto Rico · 10-acre coffee study plot.

Principal site: Copper Hill, Las Marías & Maricao, Puerto Rico

Documented period 2022 soil baseline.

Approach and context

The thesis reports 2022 baseline soil analyses in the 10-acre coffee plot. Soil pH ranged from 4.5 to 5.5, with low nitrogen, adequate phosphorus and variable potassium.

Classification: Site characterization
Research domain: Tropical Agroforestry
Research site: Copper Hill Farm, Las Marías & Maricao, Puerto Rico

Data and figures

The June 2026 NRCS CPA 106 plan, prepared by an independent consultant, maps eight soil units in its 329.4-acre planning area, dominated by Humatas (41.8%), Consumo (39.8%) and Morado (17.1%) soils. About 96% of the area lies on 20–60% slopes with high to very high runoff.

Range chart of nitrogen, phosphorus and potassium in 2022 soil analyses — 2022 baseline soil analyses in the 10-acre coffee plot. Source: McOsker (2026), ALM thesis, Harvard Extension School, pp. 169–170.

Bar chart of acres per soil map unit in the planning area — Soil map units by area within the 329.4-acre planning area. As reported in the NRCS conservation planning activity (CPA 106) plan, prepared by an independent consultant, June 2026, §4.3, pp. 9–10.

What the record supports

The program examines what nutrients leave with harvested coffee and what can return through cover crops, shade trees and amendments.

Baseline reported in the thesis; collaborator attribution awaits confirmation.

Sources and publications

All foundational studies Research inquiry