Influence of litter on herbage production in the mixed prairie.

Abstract

Lifter (dead plant material) increases production in xeric environments but the nature of this effect is uncertain. The purpose of this study was to determine the relationship between liner quantity and herbage production over a 4-year period as well as to determine the effect of repeated removal of lifter on production. The study was made in a Stipa-Bouteloua-Agropyron faciation of the Mixed Prairie association, near Lethbridge, Alberta, Canada. Litter quantity was altered by mechanical removal before spring growth and the residue separated into coarse and fine components. In Experiment 1, the effect of lifter on herbage production was tested by removing lifter at 0, medium, and high levels that resulted in an average residue of coarse liner of 1,171, 787, and 377 kg ha-1. Coarse litter was related to an increase in herbage production (P < 0.05) in 3 of the 4 years studied. The effects of lifter were related to the growing conditions of each year. The linear regression coefficients describing the response (herbage production related to litter) ranged from 0.114 to 0.802 with the smallest effect under either very dry or very wet conditions. In Experiment 2, lifter was removed at high levels in either 0, 1, 2, or 3 successive years. These treatments resulted in an average residue of coarse litter of 1,300, 164, 149, and 188 kg ha-1. Herbage production was not affected by removing litter for more than 1 year but plant height, tiller weight, and herbage yield of some plant species were.