Aims: Understanding the interplay between cattle stocking rates, soil properties, and pasture productivity remains limited for tropical pastures, as most knowledge derives from temperate grasslands. This study investigated pasture productivity responses to soil compaction under moderate (MSR, 2.7 AU.ha-1.year-1) and heavy (HSR, 5 AU.ha-1.year-1) stocking rates in Malaysian tropical pasture.
Materials & Methods: A completely randomized design with paired grazed and ungrazed plots per treatment was employed. We assessed soil compaction via bulk density (BD), penetration resistance (PR), and infiltration rate, alongside pasture productivity (biomass, regrowth, and litter). Soil (0-15 cm depth) and plant (0.25 m² quadrats) were sampled at the end of four grazing periods in 2018.
Findings: Regrowth rate was 31% greater (P < 0.05) under MSR but unaffected (P > 0.05) by HSR. Litter was reduced by 51% (MSR) and 38% (HSR) compared to controls (P < 0.05). Mean PR increased by 10% (MSR) and 32% (HSR), while infiltration decreased by 74% under HSR. Pasture production was negatively correlated with BD (r = - 0.39 MSR, r = - 0.36 HSR) and PR (r = - 0.31 MSR, r = - 0.44 HSR). A positive relationship between soil moisture and HSR occurred only under HSR (r = 0.39, P < 0.05). No significant relationship was found between infiltration rate and either stocking rate.
Conclusion: Biomass production was closely related to soil physical variables in the heavy stocking, demonstrating compaction impacts are more pronounced at HSR. Maintaining a moderate stocking rate is recommended to sustain tropical pasture productivity and prevent soil degradation.