Open AccessEffect of tillage and maize-cowpea intercrop on fractal features of particle and aggregate size distribution on a tropical sandy loam soil in southwest Nigeria
Publication year - 2020
Language(s) - English
Resource type - Journals
ISSN - 1597-4488
DOI - 10.36265/njss.2020.300113
Subject(s) - loam , silt , fractal dimension , tillage , particle size distribution , soil science , total organic carbon , particle size , mathematics , aggregate (composite) , soil water , fractal , mineralogy , agronomy , environmental science , chemistry , materials science , geology , composite material , environmental chemistry , geomorphology , biology , mathematical analysis
The effects of tillage and cropping pattern on soil aggregation, fractal dimensionsand distribution of organic carbon fractions were studied. Treatments were notillage (NT), conventional tillage (CT), and four cropping patterns viz: solemaize, sole cowpea, maize-cowpea intercrops and control (no crop). Soil sampleswere analysed for particle size distribution (PSD); aggregation ratio (AR), meanweight diameter (MWD) and aggregated silt+clay (ASC). Mass fractal dimension(Dm) was obtained from PSD; while fragmentation fractal dimension (Df) wasobtained from aggregate sizes. Total organic carbon (TOC), free and occludedparticulate organic carbon (fPOC and oPOC), were measured. Results showedthat structural stability at micro-aggregate scale measured by aggregated silt +clay (ASC) was significantly (p < 0.05) highest for NT (4.07) than CT (1.58).The CT significantly (P ≤ 0.05) reduced the larger aggregate fraction (5.66-2.00mm). The difference in fractal dimensions was significantly higher with NT thancontrol with CT. Lower difference between Dm and Df with CT represents higher degree of fragmentation of aggregates. Correlation showed significant positivelinear relationships between Dm and sand (p < 0.05, r = 0.627) and negative relationship with silt and clay (r = -0.675). Therefore, fractal dimensions derivedfrom aggregates sizes rather than particle size distribution reflected the impact ofland management practices on fragmentation of aggregates of most tropical soils.