The 2008 Joint Meeting of the Society for Range Management and the America Forage and Grassland Council.

Monday, January 28, 2008 - 4:00 PM

Combined Effects of Litter and Defoliation on Soil Moisture and Associated Forage Production in Aspen Parkland Grasslands

Eliza S. Deutsch and Edward W. Bork. Agricultural, Food and Nutritional Science, University of Alberta, 410E Agriculture/Forestry Center, Edmonton, AB T6G 2P5, Canada

Soil moisture is a limiting factor for plant growth within grasslands, including those in the Aspen Parkland of western Canada.  Litter can influence soil moisture by increasing infiltration and reducing evaporation.  Defoliation influences plant production through the removal of biomass and photosynthetically active material, and may alter soil water use.  The objective of this study was to quantify the interactive influences of varying litter loads and defoliation intensities on soil water in a Parkland environment, and link these results to associated forage production. The study was duplicated on both a native rough fescue grassland and within an adjacent tame pasture. Experimental treatments at each location included 3 litter levels and 3 defoliation treatments in a RCB design, with 5 replicates.  Litter treatments were zero (0 kg/ha), in-situ (5000 kg/ha native and 7000 kg/ha tame), and double litter (10,000 kg/ha native and 14,000 kg/ha tame), while the June defoliation treatments were undefoliated, light (6.5 cm stubble height), and heavy (2.5 cm stubble height).  Soil moisture dynamics were assessed in all plots for five consecutive days after significant rainfall events during each of May, June, July and August 2007.  Above and below ground plant biomass, plant height and seed-head densities were measured at peak biomass in August.  Initial results indicate that litter had a positive effect on retaining moisture in the soil after rainfall, with the greatest differences between the double litter treatment compared to the zero or in-situ treatments.  Biomass, seedhead counts, and plant heights also varied among the litter and defoliation treatment combinations, with plots with zero litter showing the highest values for all production parameters at both sites. In general, the effects of litter had a greater impact on plant community measures compared to defoliation within this investigation.

 

 

 

 

 

 

 

 

 


See more of Ecology
See more of Ecology

See more of The 2008 Joint Meeting of the Society for Range Management and the American Forage and Grassland Council (January 26 - 31, 2008)