Using blanket crops of ryegrass and under-seeded barley (with red clover) super-imposed on standard erosion plots just coming out of potatoes, this study assessed the influence of preceding soil-and-crop management treatments viz., straw mulch, compost and liquid pig manure (LPM) (antecedent input variables) on crop yield, soil physical properties and erosion amounts (subsequent response variables). There were no significant carry-over effects on erosion amounts, and effects on yield were limited to red clover. However, soil properties (reflecting compactability, structure and soil water retention) were affected throughout - showing general improvements of up to 46%. Thus, soil water content (SWC) was 9.4% greater with compost amendment than it was for the control. SWC with compost was also greater than it was with straw mulch by 7.9%. Soil organic matter (SOM) showed a 13% increase with compost amendment relative to the control. SOM also showed a 5% increase with compost relative to straw mulch. Compost uniquely gave yield increases in red clover, double that of the control, while LPM gave unique increases in hydraulic conductivity and SOM under red clover to the extent of 60 and 24% (respectively) relative to the control. Key words: Soil physical properties, soil erosion, organic amendments, potatoes, barley, red clover
Long-term effects of management systems on crop yield and soil physical properties of semi-arid tropics of Vertisols
