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Soil hydraulic conductivity influences hydrologic processes and the ability of watersheds to provide ecosystem services. Like most soil properties, however, it is highly spatially variable at different scales due to biophysical and anthropogenic factors. To quantify spatial variability, the study assessed the influence of land use/land cover (LULC) on soil hydraulic conductivity and compaction, as reflected by soil resistance in a small upstream watershed. Compaction was measured using a soil compaction tester and the unsaturated soil hydraulic conductivity (Kh) was estimated in the field using the inverse auger hole method. Measurements were made across six LULC: agriculture (Agri), coconut with agricultural crops (Coco + Agri), coconut with pasture (Coco + Grass), coconut with forest (Coco + Forest), reforestation area (Refo), and forest (Forest). Measurements were taken at 0–30 cm and 0–50 cm soil depths. Results showed that soil hydraulic conductivity and resistance significantly differed across LULC and soil depths. Soil resistance averages 0.83 MPa for all LULC at 0–30 cm depth, which was significantly lower (p = 1.184e–04) than 0–50 cm depth. Coco + forest recorded the highest soil resistance (1.01 MPa at 0–30 cm and 1.82 MPa at 0–50 cm), while Coco + Agri has the lowest resistance. Pairwise comparison of means also revealed that Forest at 0–30 cm depth had significantly higher (p < 0.01) Kh at 1.18 cm min–1 compared with other LULC across depths. Kh at 0–30 cm depth averages 0.57 cm min–1 for all LULC, which is significantly higher (p = 3.229e–02) than 0–50 cm depth. This indicated a decreasing hydraulic conductivity with increasing soil depth. This implies that strategies for promoting groundwater recharge and sustaining freshwater supply for lowland communities, in general, should be founded on LULC decisions, especially in upstream watersheds.

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Soil degradation is a serious problem caused by various anthropogenic activities, which threatens sustainability. An assessment of the soil quality of existing land use types is needed to come up with land management solutions for achieving sustainable use of the land. Soil health is a crucial indicator for sustainable land management and can be evaluated using the soil quality index (SQI). SQI is one of the useful tools that provide an easy understanding of the actual soil condition of different land use types. Hence, this study was conducted to evaluate the soil quality of three land use types – agriculture, agroforestry, and forest – in Liliw, Laguna through the calculation of its SQI. Soil quality was examined within the 0–20 cm soil depth of each land use having five replicates. Soil attributes such as total nitrogen, pH, organic matter, earthworms, and phosphorus served as the minimum data set for the determination of SQI. Results revealed that the SQI of the land use types followed this trend: forest (76.39%) > agroforestry (76.21%) > agriculture (49.43%). SQI of the forest and agroforestry was classified as very high, whereas agriculture had a low classification. The SQI value of agroforestry was higher than that of agriculture and closer to that of the forest. The most vital soil indicator to the overall SQI was the total nitrogen. It was confirmed in the study that agroforestry is a much better farming system approach than agriculture. Interventions such as incorporating trees – especially nitrogen-fixing tree species – using leguminous short-term crops, and prioritizing the utilization of organic fertilizers should be taken into consideration to enhance the quality of the soil in both cultivated land use types in the area. Generally, this study recommends the prioritization of agroforestry as a technology to be implemented in various programs related to sustainable farming.