Adaptation of Bermudagrass to the Texas High Plains[1]

 

Summary of Results from Small Plot Trials

 

Mark A. Marsalis, Texas Tech University

 

Justification

 

            The focuses of this research are the issues of water use and quality, forages suited for limited water situations and their relationship with sustainable agriculture on the Southern High Plains of Texas.  We are nearing a time when significant changes in resources will affect greatly the present agricultural practices and productivity of this region of the U.S.  As human populations increase rapidly and water quality and quantity continue to diminish, the importance of sustainable cropping systems weighs heavier on producers than ever before.  Likewise, research in this area is critical and necessary in order to understand better and manage the natural resources that are threatened.  Cotton (Gossypium hirsutum), by far, is the most extensively grown crop on the Texas High Plains.  The greater than 3.5 million acres of cotton grown annually account for 20 to 25 percent of total U.S. cotton (USDA, 1989).  Unfortunately, about half of the water applied to cotton through traditional irrigation systems is wasted via runoff and evaporation.  In addition, traditional cropping systems promote wind-induced soil erosion and reduced soil fertility.  With cotton being the largest cash crop on the Southern High Plains and the major user of water, the current methods of irrigation will hasten the depletion of ground water sources and ultimately hinder the productivity of this land. 

            Grazing systems are potentially viable, sustainable alternatives to the cotton monoculture.  There is no doubt that the cattle industry is an important component of Texas agriculture and economy.  Eight of the ten counties in Texas that contribute to its leading all other states in numbers of beef cattle are located in the High Plains, which has also the highest concentration of feedlot cattle in the U.S. (Texas Agricultural Statistics Service, 1994).  As cattle numbers increase, improved grazing systems must be developed in order to complement the conservative water use systems necessary in the future. 

            As good quality water for irrigation is being limited increasingly to municipal use, more poor quality water is allocated toward crop production (e.g. effluent water, saline aquifers).  This raises the question of potential salinization within soils.  Therefore, it is essential to test salt and drought tolerant forages that could be incorporated into these potentially challenging systems.  Bermudagrass [Cynodon dactylon (L.) Pers.], because of its tolerance to drought and relatively saline conditions, may qualify as a strong candidate for such situations.  Bermudagrass is a warm-season perennial grass that appears to have originated in southeast Africa.  Introduced in the U.S. as early as 1751, it quickly became one of the most important pasture grasses in the South.  It is best adapted where mean daily temperatures are above 75º F (24º C).  Little is known about the adaptation of bermudagrass to West Texas and therefore, should be tested to determine its suitability to the unique environmental conditions of the region.  Recently, increasing numbers of producers have requested information on bermudagrasses.  Because it is lacking, we have sought to obtain this information through research and through an organized effort to survey producers about their experiences with bermudagrass in the region. 

 

Overall Objective

 

Expand the knowledge of bermudagrass adaptation to the stressful environmental conditions of the Southern High Plains by evaluating factors such as salt tolerance, growth and nutritive value under limited irrigation, and ultimately, the potential of bermudagrass as a component of sustainable forage-livestock systems.

 

Specific Objectives

 

  • Determine adaptation of bermudagrass varieties and hybrids to the High Plains of Texas.
  • Estimate the survival, growth, and nutritive value of the bermudagrasses under limited and saline irrigation conditions. 
  • Evaluate the role of bermudagrass for use in wastewater disposal applications.
  • Determine forage quality of several varieties harvested at 28-day intervals.

 

 

These are the current establishment and production phase results from all locations of bermudagrass small plot research being conducted by Mark Marsalis, Dr. Vivien Allen, and other faculty at Texas Tech University as well as various professionals associated with each site of planting.  Measurements to be taken will include forage mass samples taken every 28 days to estimate production during the growing season.  In addition, grasses will be analyzed for forage quality and will include analysis of fiber, crude protein, carbohydrate (TNC), and mineral content.  Following every 28-day harvest, all plots will be fertilized with nitrogen at a rate of 60 lb. per acre.  All plots were planted in spring 2001 and research will continue through at least fall 2003.  

It should be noted that some of the information presented is establishment year results and should be interpreted as such.  Results obtained from the planting year often times differ greatly from subsequent years of production, which may be the case with our studies in the future.  In addition, these data should not be interpreted to mean that bermudagrass would perform the same under all conditions or at any location.  Our findings are site specific and results will vary with differing management practices (e.g. irrigation method, fertilizer inputs, planting rate, etc.). 

Establishment phase results are presented as visual ratings of ground coverage (except with seeded varieties) and canopy height measurements.  Production of the plots is presented as forage mass harvested and includes only one harvest from the New Deal location for the 2001 growing season.  A list of bermudagrass varieties and other plant species used is included.   

Research was initiated in spring 2001 at three locations:  Texas Tech Field Research Laboratory, New Deal, TX; Southwest Public Service (SPS) agricultural land, Posey, TX; and City of Midland effluent water application farms, Midland, TX. 

 

Planting

 

At the Texas Tech Field Laboratory all bermudagrass varieties were planted on May 11, 2001 in 1.86-m2 plots.  Sprigged types were planted in a 3-row arrangement within each plot.  Sprigs were placed in the rows, covered with soil to about 5 cm, and then rolled to compact the soil.  Seeded varieties were broadcast within their respective plots at a high rate to ensure good establishment.  Seeds were then raked into the newly disturbed soil and compacted.  Twelve bermudagrass varieties are being studied at this location (See attached map).

            Bermudagrasses (five varieties) at the Midland site were planted on May 10, 2001 via sprigs and in the same manner as those described previously at the Texas Tech Field Laboratory.  In addition to bermudagrass, [Sporobolus virginicus (L.) Kunth], a salt tolerant marsh grass, is being studied.  This grass is a warm-season perennial with high drought and salt tolerance and may have potential for use as a forage under saline conditions.  The S. virginicus plugs (58 cm2 each) were planted in a 3X4 arrangement within the 1.86-m2 plots by placing them in relatively shallow holes and covering them with soil. 

Due to extra time needed to eliminate existing stands of ‘Jose’ tall wheatgrass [Thinopyrum ponticum (Podp.) Barkw. & D.R. Dewey] in the planting area and time required to negotiate cooperation agreements, the site at the Southwestern Public Service farm was planted somewhat later than the other two sites, on June 14, 2001.  Planting methods were identical to those of the Midland site.

 

Irrigation

 

At the site near New Deal, plots are irrigated with good quality Ogallala Aquifer water via a NetafilmÒ subsurface drip irrigation system.  The rate of irrigation is 2.54 mm (0.10 inch) per day throughout the months of May, June, July, and August to supplement precipitation in order to supply at least 76.2 mm (3 inches) per month.  A maximum of 305 mm (12 inches) of irrigation water per year is applied.  This amount gives a theoretical total of 762 mm (30 inches) when considering rainfall contributions. 

            The Midland location receives irrigation from City of Midland wastewater holding ponds near the plot site.  Total dissolved solids of the wastewater are about 1700 mg L-1.  This water is applied through a side roll linear irrigation system used to irrigate adjacent alfalfa (Medicago sativa L.) fields.  Timing of watering coincides with that designated for alfalfa production at the site. 

            Plots at the Posey location are irrigated with industrial cooling tower water from the nearby Jones Station of Southwestern Public Service.  This water is very high in TDS, about 7000 mg L-1, and contains appreciable amounts of sulfate and sodium.  Water comes from holding ponds through a center pivot irrigation system.  Amount of water applied is dependent upon availability and allotment to surrounding crops at the site. 

 

 

Establishment Phase Dates

 

 

New Deal:

 

            Planting- May 11, 2001

            Visual Rating & Canopy Height Measurements- Day 49- June 27, 2001

            Forage Mass Harvest- September 14, 2001

 

Midland:

 

            Planting- May 10, 2001

            Visual Rating & Canopy Height Measurements- Day 70- July 19, 2001

 

Posey:

 

            Planting- June 14, 2001

            Visual Rating & Canopy Height Measurements- Day 70- August 23, 2001

 

 

Visual Rating Scale

 

1= No Spread from Original Planting Row

2= Minimal Spread

3= 50% of Plot Covered

4= 75% of Plot Covered

5= 100% Coverage

 

 

Bermudagrasses Studied

 

New Deal, TX                                                              Midland & Posey, TX

 

Tifton 85                      X                                             Tifton 85

Tifton 44                      Sumrall 007                              Coastal

Coastal                         Giant                                        Midland 99

Midland 99                   Wrangler                                  World Feeder

Hardie                          Cheyenne                                 X

World Feeder               Sahara                                      Sporobolus virginicus (Seashore dropseed)

 

 

Establishment Phase Results

 

Normal Irrigation Site- New Deal, TX

 

Figure 4.9. Visual ratings of ground cover during establishment of bermudagrasses grown at New Deal, TX on 27 June 2001, 49 d after planting. † SE = Standard error of the mean; n = 4 for each mean. a,b,c,d,e Means with the same superscript are not different (P > 0.05). ‡ Rating scale: 1 = no coverage, still in rows; 2 = minimal spread from rows; 3 = 50% of plot covered; 4 = 75% of plot covered; 5 = plot covered completely, no ground visible. Bars in white indicate seeded varieties.

 

Figure 4.10. Canopy heights of bermudagrasses grown at New Deal, TX on 27 June 2001, 49 d after planting. † SE = Standard error of the mean; n = 4 for each mean. a,b,c,d,e Means with the same superscript are not different (P > 0.05).

 

 

 

Effluent Irrigation Site- Midland, TX

 

 

Figure 4.19. Visual ratings of ground cover of bermudagrasses and Sporobolus virginicus grown at Spraberry, TX on 19 July 2001, 70 d after planting. † SE = Standard error of the mean; n = 4 for each mean. a,b,c  Means with the same superscript are not different (P > 0.05). ‡ Rating scale: 1 = no coverage, still in rows; 2 = minimal spread from rows; 3 = 50% of plot covered; 4 = 75% of plot covered; 5 = plot covered completely, no ground visible.

 

Figure 4.20. Canopy heights of bermudagrasses and Sporobolus virginicus grown at Spraberry, TX on 19 July 2001, 70 d after planting. † SE = Standard error of the mean; n = 4 for each mean. a,b,c  Means with the same superscript are not different (P > 0.05).

 

 

 

 

Industrial Wastewater Irrigation Site- Posey, TX

 

 

Figure 4.29. Visual ratings of ground cover of bermudagrasses and Sporobolus virginicus grown at Posey, TX on 23 Aug. 2001, 70 d after planting. † SE = Standard error of the mean; n = 4 for each mean. a,b,c  Means with the same superscript are not different (P > 0.05). ‡ Rating scale: 1 = no coverage, still in rows; 2 = minimal spread from rows; 3 = 50% of plot covered; 4 = 75% of plot covered; 5 = plot covered completely, no ground visible.

 

 

Figure 4.30. Canopy heights of bermudagrasses and Sporobolus virginicus grown at Posey, TX on 23 Aug. 2001, 70 d after planting. † SE = Standard error of the mean; n = 4 for each mean. a,b,c  Means with the same superscript are not different (P > 0.05).

 

 

 

Production Phase Harvest Dates

2002

 

New Deal:                                   Midland:                                       Posey:

           

            May 9                                      April 25                                    May 16

            June 8                                      May 23                                    June 13

            July 6                                       June 20                                    July11

            August 1                                   July 18                                     August 8

            August 30                                 August 15                                 September 5

                                                            September 12

 

 

 

Forage Mass- By Harvest Date