A comparison of soil and water properties in organic and conventional farming systems in England

Abstract

Organic farming and improvements to agricultural sustainability are often seen as synonymous. However, an extensive European review demonstrated that in practice this is not always true. This study aims to compare the status of soil and water properties between separate fields managed in either an organic or a conventional manner. Soil samples were collected from 16 pairs of farms, throughout England, with both arable and grass fields within each pair on similar soil type. Chemical (nutrients, pesticides, herbicides) and physical (aggregate stability, field capacity, shear strength, soil organic matter, infiltration rates) soil properties were measured in four main soil texture classes in organic and conventional fields. The physical soil properties varied significantly between the different classes of texture and land use. The heavier textured soils have significantly higher soil organic carbon (SOC), aggregate stability and shear strength. The coarse‐textured soils have significantly lower field capacity moisture contents. The grassland has a significantly higher level of SOC, field capacity moisture content, aggregate stability and soil shear strength. However, there were no significant differences between organic and conventional treatments for any of the soil physical properties measured. There were fewer traces of agrochemicals in the soil water from the organic fields compared with the conventionally managed fields. The conventional arable fields had higher levels of total inorganic nitrogen than the other land uses and treatments. There was evidence to show that infiltration rates were significantly higher on organically managed grassland soils (7.6 mm/h) than conventionally managed grassland (2.5 mm/h) with lower stocking rates. The results suggest that improved grassland management, whether organic or conventional, could reduce predicted runoff by 28%.

Soil properties after 10 years of organic versus conventional management in two greenhouses in Almeria (SE Spain)

“…Moral et al only in the 100-800 kPa range, probably due to differences in pore size distribution. Hathaway-Jenkins et al (2011) showed similar results in coarse-textured soils, highlighting the importance of the different classes of texture when comparing physical soil properties. Nevertheless, greenhouse growers, by their high-frequency irrigation systems, usually maintain soil moisture tension in the range 20-60 kPa (Del Moral 2009) where no differences were observed between these two forms of management.…”

Management of crop water under drought: a review

“…We notice here that, in a meta-study of Hathaway-Jenkins et al (2011), no differences were found between conventional and organic farming systems. Similar to other management measures, also crop rotation studies reveal the importance of the time scale of changes (Głąb et al 2013).…”

The ‘Neighbourhood Effect’: A multidisciplinary assessment of the case for farmer co-ordination in agri-environmental programmes

“…Lower stocking density of livestock can be expected to cause less soil damage and could facilitate better infiltration of water into soil. Further details of the soil and water research can be found in Hathaway-Jenkins et al (2011).…”