Cultivatino practice, sowing season and soil erosion on the South Downs, England: a preliminary study

Summary Seven plots were laid out for the 1985–6 growing season on the Chalk Downs near Lewes, East Sussex, to study the relationship between cultivation practice, soil conditions and erosion rates. Three plots were sown with cereals in autumn and three in spring. The seventh plot was ploughed and kept bare. In both spring and autumn, one plot was conventionally cultivated by ploughing and harrowing, one was direct drilled through burnt stubble and the third was direct drilled through the debris of the previous year's straw and stubble. Erosion was greatest from the conventionally cultivated plots and least from those direct drilled through unburnt stubble. Monitoring of moisture, infiltration, strength and compaction properties of soils suggests that from late autumn onwards soil conditions on the plots were very similar and the major factor determining the different erosion losses from the plots was the percentage vegetal cover (crop, weeds and residues). The results suggest that direct drilling through unburnt stubble may be a way of obtaining high yields with low erosion risk on the Downs, but the long-term consequences of such a practice remain unknown.