Publication Date:
1984-11-01
Description:
A 5-yr field study was conducted at Charlottetown, Prince Edward Island to determine the effect of losses of topsoil and organic matter likely to accrue from intensive potato production on the crop production potential of a loam to fine sandy loam Podzolic Grey Luvisol representative of major soil types used for potato production on P.E.I. The top 7.5 or 15 cm of the original 20-cm-thick Ap horizon was removed from strips on either side of a control (intact soil) strip. These strips were cropped under a 5-yr potato-barley rotation. Soil-loss treatments reduced the organic carbon content of the new 20-cm-thick Ap horizons formed by tillage by 9.4 and 37%, respectively, from 51.3 tonnes (ha∙20 cm)−1 in the original Ap horizon. Similarly, mineralizable nitrogen levels were reduced initially by 21 and 64%, respectively, compared with the intact soil. During the subsequent 2 yr, mineralizable nitrogen levels in the Ap horizons of the intact and minus 7.5-cm strips fell by 35%. Soil-loss treatments had no effect on Ap horizon texture, porosity, or bulk density. However, losses of topsoil reduced the soil’s capacity to store plant-available water (33 kPa – 1500 kPa) within the rooting zone above a Bt, horizon (bulk density 1.67 tonnes∙m−3) by 1.3 and 3.4 cm of water, respectively, from 9.8 cm for the intact soil. Rainfall patterns on P.E.I. suggest that such reductions in water storage capacity may reduce the soil’s crop production potential in 2 out of 5 yr. Key words: Topsoil loss, intensive cropping, Luvisol, organic carbon, mineralizable nitrogen, water storage capacity
Print ISSN:
0008-4271
Electronic ISSN:
1918-1841
Topics:
Geosciences
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Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
