Soil Quality in CRP Lands of Eastern New Mexico.

Conservation Reserve Program(CRP) is a voluntary, federal program offering annual rental payments and cost-share assistance to farmers who establish long-term vegetation covers on their erosion prone lands. The purpose of this program is to protect the land and promote environmental benefit such as clean air, clean water and soil preservation. Another possible benefit that long-term grasses in CRP lands can provide,  is the improvement in soil quality and carbon sequestration. A study was conducted to evaluate selected soil quality indicators in lands that have been in CRP for at least 15 years in Roosevelt County of New Mexico State, comparing them with adjacent farm lands. Samples (0-0.15 m) were taken from CRP fields in either native grasses or weeping lovegrass. Sampling was planned to include CRP sites with both coarse and fine textured soils, and for each site, adjacent farmland belonging to the same soil mapping unit were sampled for comparison. Soil indicators assessed included bulk density, penetration resistance, dry aggregate size distribution, soil organic matter, permanganate oxidizable carbon, nitrate nitrogen, extractable potassium and phosphorus, electrical conductivity, pH and sodium adsorption ratio. Results showed a significant effect of CRP management only for bulk density and soil penetration resistance, with the CRP fields being less compacted than the farm fields. CRP land did not significantly differ from farmlands in soil organic matter and for other measured indicators. However, the effect of soil texture was significant, with the fine textured soils having generally more favorable indicator measurements than the coarse textured soils. There were also no significant differences in soil measurements between the CRP fields in native grasses and weeping lovegrass. CRP management did not appear to have led to any significant carbon sequestration at 0-0.15 m especially in coarse textured soils of the studied site.