Short-term effects of crop rotation, residue management, and soil water on carbon mineralization in a tropical cropping system

• Published in: Plant and soil 2008-10, Vol.311 (1-2), p.29-38
• Main Authors: Adiku, S. G. K, Narh, S, Jones, J. W, Laryea, K. B, Dowuona, G. N
• Format: Article
• Language: English
• Subjects: Agricultural practices; Agricultural site preparation; Agriculture; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Biological and medical sciences; Biomedical and Life Sciences; Carbon; Corn; Crop management; Crop residues; Crop rotation; Cropping systems; Decomposition; Ecology; Equilibrium; Fallowing; Field capacity; Forest soils; Fundamental and applied biological sciences. Psychology; Grasses; Legumes; Life Sciences; Maize-fallow rotation; Mineralization; Moisture content; Plant Physiology; Plant Sciences; Regular Article; Residue management; Rotation; Soil carbon mineralization; Soil Science & Conservation; Soil sciences; Soil water; Soil water content; Tillage; Water content
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-008-9652-y

The purpose of this study was to investigate the short-term effects of maize (Zea mays)-fallow rotation, residue management, and soil water on carbon mineralization in a tropical cropping system in Ghana. After 15 months of the trial, maize-legume rotation treatments had significantly (P < 0.001) higher levels of potentially mineralizable carbon, C ₀ (μg CO₂-C g⁻¹) than maize-elephant grass (Pennisetum purpureum) rotations. The C ₀ for maize-grass rotation treatments was significantly related to the biomass input (r = 0.95; P = 0.05), but that for the maize-legume rotation was not. The soil carbon mineralization rate constant, k (per day), was also significantly related to the rotation treatments (P < 0.001). The k values for maize-grass and maize-legume rotation treatments were 0.025 and 0.036 day⁻¹ respectively. The initial carbon mineralization rate, m ₀ (μg CO₂-C g⁻¹ day ⁻¹), was significantly (P < 0.001) related to the soil water content, θ. The m ₀ ranged from 3.88 to 18.67 and from 2.30 to 15.35 μg CO₂-C g⁻¹ day⁻¹ for maize-legume and maize-grass rotation treatments, respectively, when the soil water varied from 28% to 95% field capacity (FC). A simple soil water content (θ)-based factor, f w, formulated as: [graphic removed] , where θ d and θ FC were the air-dry and field capacity soil water content, respectively, adequately described the variation of the m ₀ with respect to soil water (R ² = 0.91; RMSE = 1.6). Such a simple relationship could be useful for SOC modeling under variable soil water conditions.