Relationship between termites, straw amendment and the growth of <i>Erioneuron pulchellum</i> in a Chihuahuan Desert ecosystem

TitleRelationship between termites, straw amendment and the growth of Erioneuron pulchellum in a Chihuahuan Desert ecosystem
Publication TypeThesis
Year of Publication1983
AuthorsBrown MFrederick
Number of Pages109
Date Published1983
UniversityNew Mexico State University
CityLas Cruces, New Mexico
Thesis TypeM.S. Thesispp
Call Number00023
Keywordsdissertation, dissertations, Erioneuron,growth, grass, Erioneuron, nutrient ammendment, straw, nutrient, nitrogen, soil nitrogen, termite, termite,soil nitrogen, termite,straw, theses, thesis
Abstract

The aim of this study was to examine the effect of termite removal, straw amendment, and supplemental watering on the growth of a perennial grass, Erioneuron pulchellum, in relation to total soil nitrogen levels in a Chihuahuan desert, New Mexico. Four blocks consisting of four 30 x 40 M plots were used in a randomized block design. In 1977, 10 kg ha-1 of chlordane was applied to two of the plots followed by 1800-2000 kg ha-1 of straw added in 1981. Treatments consisted of strw with termites, straw without termites, termites alone and no termites. Soil samples were taken an four dates from 06/81 to 09/82, at half and twice canopy radii of creosotebushes and at 0-5 and 5-10 cms depth at each location. Samples were analyzed for soil organic matter and for total soil nitrogen by microkjeldahl digestion. Results showed that organic matter and total nitrogen was highest under creosotebush conopies and at 0-5 cm depths. Plots with termites had lower soil nitrogen than those without and plots with straw had higher soil nitrogen when termites were present. E. pulchellum grew better on plots with termites and plots with straw than with both termites and straw and no termites and no straw. Total soil nitrogen was not implicated as contributing to these differences. The long-term effects of termite removal which contribute to reduced soil stability and water holding capacity resulted in reduced biomass production of E. pulchellum. It is suggested that termites contribute to the overall growth and survival of E. pulchellum by supplying nitrogen through recycling of above ground dead material and via carton dissolution. Carton construction is suggested to provide structural stability to the grass tussock. Supplemental watering of E. pulchellum indicated that water acted independently of the treatments although it did result in increased root nitrogen and above ground biomass of E. pulchellum, indicating a possible short-circuiting of the nitrogen available in the soil.