The Use of Regression in Range Research

Abstract

of thesis submitted in partial fulflUment of the requirements for the degree of Master of Sciencee, Department of Range & Forestry, Agricultural & Mechanical College of Texas, 1955. Five important range grasses of Texas were planted during the fall and winter of 1953-54, on an abandoned cultivated field near College Station, Texas. Plantings of big bluestem, silver bluestem, Indian grass, side-oats grama, and little bluestem were made on four dates: November 21, January 2, February 6 and March 5. Plantings were made of each species on the surface and at depths of 1/4, '/2, 3/4, 1 and 1'/2 inches. On May 27, three fertilizer treatments were made: top dressing, hand dressing applied at the rate of 90-45-0 per acre and no fertilizer. All plots were weeded at various intervals. Plantings of big bluestem resulted in relatively poor stands with few plants. A majority of these, plants resulted from the February and March plantings. Establishment 'of plants was greatest for the 1/4and /2-inch depth plantings. Relatively large numbers of silver bluestem plants were established at all planting dates, with maximum in March and minimum in February. Planting at depths of 1/4 and 1/2 inch resulted in greater establishment than at other depths. Planting at 11/2-inch depth resulted in failure for all dates of planting. Indian grass produced a comparatively substantial number of plants for all dates of planting. This grass showed the least variation in plant numbers for the various dates of planting of all the grasses observed. Plantings at depths of 1/4, 1/2 and 3/4 inch resulted in from fair to excellent stands for all dates of planting. All 11/2-inch depth plantings rated poor. Results from surface plantings were erratie, and ranged from no plants to good stands. Side-oats grama produced the greatest number of plants of any of the grasses. The November and January plantings resulted in poor emergence whereas the February and March plantings resulted in good to excellent emergence. Planting depths from ,4 to I inch for the February and March plantings resulted in stands that rated excellent. Surface plantings rated fair to excellent. Planting depths of 11/2 inch resulted in poor stands for all dates of planting. Counts of lit-tle bluestem were considerably higher for the February and March plantings than for the November and January plantings. Planting depths of 1/4 and 1/2 inch for this grass resulted in the best stands of any of the depths. Surface and 3/4-inch depths resulted in poor to fair stands, 1-inch depths in poor to no stands, and 11/2-inch depths in no stands. Fertilizer applied as a top dressing to the five grasses appeared to give better results, as related to height of plant and herbage production per foot of vegetation, than the hand dressing and no fertilizer. Big bluestem was the only grass not reflecting these results. Indications were that band dressing was slightly les favorable than no fertilizer. This may have been due to poor soil moisture conditions at the time of application and for a considerable period thereafter.-JAMES E. ANDERSON, Department of Animal Husbandry, New Mexico Agricultural & Mechanical College, State College,, New Mexico. This content downloaded from 207.46.13.150 on Thu, 28 Jul 2016 04:32:38 UTC All use subject to http://about.jstor.org/terms