Using Selected Structural Indices to Pinpoint the Field Moisture Capacity of Some Coarse-Textured Agricultural Soils in Southeastern Nigeria

摘要: Over- or underestimation of field capacity (FC) agricultural soils could misguide soil and water management this might have negative agronomic environmental impacts. The study sought to identify the moisture tension for reliably estimating in laboratory FC some sandy with low-activity clay minerals at different levels structure development Nsukka agroecological zone southeastern Nigeria. Fifty-four samples topand subsoils under contrasting vegetation cover three locations were analyzed texture, organic matter contents, bulk density total porosity. Saturated hydraulic conductivities (Ksat) equally determined. Water-conducting water-filled porosities each 0.06-, 0.10- 0.33-bar tensions implied from retention data respective tensions. categorized based on their using a structural stability index [(organic matter: silt+clay) %] as follows: very low ( 7.5%) soils. Series simple correlation tests run among waterconducting various Ksat In case, was assumed attained that which associated water-conducting porosity showed significant positive Ksat. Our results revealed 0.06-bar overestimated 0.10-bar tension, commonly used purpose area, proved suitable only within moderate high category. From all indications, best corresponded less structurally developed other two categories. level should therefore be considered before deciding determination these similar tropical locations. Keywords: Coarse mineral soils, capacity, saturated conductivity, stability, pores