Spatiotemporal variability of eroded organic matter, nitrogen, and nitrate in response to monsoonal changes in a black pepper farm

Organic matter (OM), total nitrogen (N) and nitrate (NO3) underpin soil fertility in black pepper farms, yet nutrient redistribution and losses can intensify under alternating monsoonal wet–dry regimes on steep, sandy terrain. This study quantified the spatiotemporal variability and inter-relationships of OM, N and NO3 across four monsoonal phases (Inter-April, Southwest, Inter-October and Northeast) using 264 surface soil samples (0–20 cm) from a 1.5 ha farm. Descriptive statistics, Pearson correlation and geostatistical mapping (semivariograms and Ordinary Kriging) were applied. Monsoonal transitions, compounded by a 26° slope, high sand content (>78.49%) and limited vegetative cover (35.06%), produced marked seasonal contrasts. Relative to Inter-April, OM and N increased by 24.3% and 22.1% during the Southwest monsoon, while NO3 rose by 86.0%, indicating temporary retention under lower rainfall. During the subsequent shift toward the Northeast monsoon, NO3 declined by 53.0, coinciding with high rainfall (1,223 mm) and enhanced leaching/runoff. Spatial dependence also shifted, with OM showing moderate dependence (27.175%) and NO3 consistently weak spatial dependence (<3%), reflecting high mobility and redistribution. Correlations among OM, N and NO3 varied by season, underscoring the sensitivity of nutrient coupling to moisture regime changes. Overall, results demonstrate that monsoonal timing strongly governs nutrient availability and loss pathways in coarse-textured, sloping pepper farms. Improved management particularly aligning fertiliser timing with crop demand and strengthening soil conservation (e.g., cover cropping and terracing) is recommended to mitigate losses and stabilise fertility.

Text 123441.pdf - Published Version Download (685kB) Official URL or Download Paper: https://journals.utm.my/jurnalteknologi/article/vi...

Actions (login required)

View Item