Long- and short-term effects of cultivation on properties of a Vertisol under sugarcane plantation

Abstract

The effect of long- (>40 years) and short-term (<10 years) cultivation on some soil properties in sugarcane (Saccharum officinarum L.) grown on a Vertisol were compared to native vegetation in the semi-arid tropical region of Sudan. Tillage practices were sub-soiling, smoothing by disc harrowing, leveling and ridging (done every 4–5 years) and re-ridging annually. Particulate organic matter (POM) with long-term (8.2 g kg 1) and short-term cultivation (6.6 g kg 1) were significantly (P 0.007) higher than for native vegetation (2.1 g kg 1). In the 0–10 cm soil depth, cultivation had no effect on total nitrogen (TN), organic carbon (OC) and bulk density (Bd). However, in the 10–20 cm soil depth, significantly (P 0.03) greater N was present under the long-term cultivation (0.46 g kg 1) than under native vegetation and short-term cultivation (0.26– 0.33 g kg 1). At 10–20 cm, soil bulk density under long-term cultivation (1.5 mg m 3) was lower (P 0.01) than under short-term cultivation (1.8 mg m 3) and native vegetation (1.7 mg m 3). At 20–30 cm, TN and bulk density were not affected, but OC was significantly (P 0.009) higher under native vegetation (4.9 g kg 1) than under short-term cultivation (1.7 g kg 1). It could be concluded that, long-term production of sugarcane in fine textured soils (>52% clay) improved soil properties relative to native vegetation in the semi-arid tropics.