Response of Soil Properties to Land Use Change from Wheat to Pig Production

Abstract

A significant change in land use has been a continued increase in large, intensive outdoor pig production which is largely fueled by increased economic and market forces. While this change has solved the need for animal welfare, customer satisfaction of natural and organic pork and the need for reduced capital input to sustain business for farmers, the environment, however, stand at no gain to the present moment. Increased accumulation of N surplus in soil has continued to increase leaching propensity, threatening surface water pollution. In this study, an investigation was conducted at Field Research Unit, University of Leeds Farm Ltd to determine the possible changes on soil from transformation from wheat to pig production. Soil core samples were collected from two paddocks Gilt and Gilt Train each stocked with 30 gestating sows ha-1 for 3 and 2 weeks respectively, and from adjacent analogous field without animals (control) at 0-5 cm depth before and after the introduction of pigs. Soil pH, soil texture, soil moisture, soil dry matter, water holding capacity, soil organic matter and N mineralization were measured. Laboratory analysis on soil pH and soil texture indicated that there was no change in the two soil properties from before and after the introduction of pigs. One-way analysis of variance (ANOVA) conducted on samples before the pig introduction (n=18) to determine difference in space, indicated that moisture content (P 0.05) in any of the soil properties mentioned under the three soils treatments. One-way repeated measures ANOVA were also employed to determine change in time. Similar soil properties were compared and the results showed that, moisture content (P<0.0005), dry matter content (P<0.0005) and N mineralization (P<0.05) were statistically significantly different under soils in time. However, transformation did not elicit statistically significant change under soils in water holding capacity (P=0.905) and soil organic matter (P=0.477). Overall, this short term finding demonstrated that land use change from arable crop to outdoor pigs production had no effect on soil physical properties. Low organic matter deposition from the pigs had affected the rate of N mineralization and consequently the soil moisture and the dry matter content of the soils. Moisture content and dry matter could also be affected by the frequency and intensity of pigs treading, which causes compaction. Subsequent studies could measure compaction effect from outdoor pig system.