Seasonal distribution of runoff and soil loss under four tillage treatments in the upper St. John River valley New Brunswick, Canada

Abstract

Chow, T. L., Rees, H. W. and Monteith, J. 2000. Seasonal distribution of runoff and soil loss under four tillage treatments in the upper St. John River valley New Brunswick, Canada. Can. J. Soil Sci. 80: 649-660. The effect of four different tillage treatments on surface runoff and soil loss, their seasonal distribution and temporal variation in soil erodibility were examined using runoff-erosion plots (10 m wide × 30 m long), on a Holmesville gravelly loam soil, a major soil type used for potato production in New Brunswick. Fall moldboard plowing, fall chisel plowing, spring moldboard plowing and subsoiling followed by fall moldboard plowing were evaluated under barley and fallow conditions on 8 and 11% slopes between 1989 and 1993. With exception of one year, annual precipitation was lower than normal. However, due to higher rainfall during the cropping season, the calculated erosivities were higher than those typically used for conservation planning in this region. Runoff data revealed that fall moldboard plowing generated the highest runoff. Either performing subsoiling prior to fall moldboard plowing or delaying moldboard plowing until the next spring, reduced runoff by approximately 10%. Chisel plowing, which loosens the soil without inverting it and leaves a large amount of residues on the surface, provided by far the greatest benefit in reducing runoff (20% reduction over fall moldboard plowing). Soil loss from fall moldboard plowing on the 11% slope under fallow was 2.8 and 2.6 times greater than from spring moldboard plowing and fall chisel plowing, respectively. The majority of the difference in soil loss occurred during the summer months. The benefit of spring moldboard and fall chisel plowing was considerably less on the 8% slope in which soil loss from the fall moldboard plowing was only 24 and 19% higher than spring moldboard and fall chisel plowing, respectively, indicating that the benefits are slope dependent and increase with increasing slope from 8 to 11%. When the plots were planted in Chapais barley (Hordeum vulgare L.), soil losses were negligible. Tillage treatments, and particularly cropping practices, play a major role in seasonal distribution of runoff and soil loss. Under fallow, approximately 79% of runoff and 8.1% of soil loss occurred during the non-cropping season whereas 96% of runoff and 68% of soil loss were found when the plots were planted in barley. The soil erodibility factor was two to three times higher during March and April, which coincide with the winter-spring thaw period, than during the rest of the year. This seasonal variation must be considered when using event-based models to predict soil losses. Nous avons examiné l'effet de quatre régimes de travail du sol sur le ruissellement et sur les déperditions de sol, sur la répartition saisonnière et sur les variations en fonction du temps de l'érodibilité du sol. Les parcelles étaient installées sur loam graveleux Holmesville, principal type de sol utilisé pour la culture de la pomme de terre au Nouveau-Brunswick. Les ...

Residual effects of fallows on selected soil hydraulic properties in a kaolinitic soil subjected to conventional tillage (CT) and no tillage (NT)

“…Fallows also had more pores which were involved in the transport process, (Table 3), Note: means in the same column followed by the same letter are not significantly different at P = 0.05 Different symbols ( a,b ) shows significant differences, same symbols shows no significant differences resulting in higher hydraulic conductivities. Although there have been reports to the effect that CT can destroy soil structure relative to NT (Ankeny et al 1990;Stonehouse 1991;Nyagumbo 2002 andChow et al 2000), there were no significant differences in hydraulic conductivities between CT and NT. This may be because the duration in which the plots were under the two tillage systems was short for any tillage effects to be shown.…”

Hay mulching to reduce runoff and soil loss under intensive potato production in northwestern New Brunswick, Canada

“…It is characterized by 30-50 cm of friable topsoil over a dense compact subsoil (bulk density of 1.7-1.8 Mg m -3 ). The plots are described in detail in Chow et al (1990Chow et al ( , 2000. An automated weather station with a Campbell Scientific CR10X 1 data logger (Logan, Utah) and RIMCO heated tipping bucket precipitation gauge (McVan Instruments, Victoria, Australia; sensitivity 0.1 mm) was used to collect data on precipitation.…”

“…Winter ground cover is required in Prince Edward Island as most of the soil loss from potato fields occurs during the cool period of late fall to early spring . However, in New Brunswick, a majority of the annual soil loss is induced by the high-intensity erosivity of summer thunderstorms occurring during the growing season, particularly in June, July and August (Chow et al 1990(Chow et al , 2000.…”

Hydrology and water quality across gradients of agricultural intensity in the Little River watershed area, New Brunswick, Canada

“…These deposited sediments were washed into the stream during the spring snowmelt events when the water level was higher. The deposited sediment became soil loss, which was measured during snowmelt period (Chow et al 2000). In addition, the higher proportion of farmland in the BBW was also responsible for the dramatic increase in sediment during the snow melting season (because over 60% of the farmland used for potato production was left bare over winter ) in the ULRW (figure 3b).…”

“…To examine water runoff or soil loss, cumulative precipitation and erosivity (Wischmeier and Smith 1978;Chow et al 2000), a derived expression of rainfall amount and maximum intensity, are normally calculated along with considerations of land management (Wischmeier and Smith 1978). Velocity of runoff plays a major role in sedimentation mechanisms, which can be more or less affected by the land use and type and amount of vegetative cover (Foster and Carter 1983).…”