Selecting Small Grain Forages for the Southern High Plains

Selecting Small-Grain Forages for the Southern High Plains

Mark A. Marsalis, Extension Agronomist, Agricultural Science Center at Clovis, New Mexico State University, Clovis 88101; Leonard M. Lauriault, Forage Agronomist, Agricultural Science Center at Tucumcari, New Mexico State University, Tucumcari 88401; and Dawn M. VanLeeuwen, Agricultural Biometrician, Agricultural Biometrics Service, Agricultural Experiment Station, New Mexico State University, Las Cruces 88003

Abstract

Information is lacking on the relative performance of small-grain forage types grown for hay or silage on the High Plains of New Mexico and West Texas. Tests were conducted from 2004 to 2008 at Clovis, NM, to determine long-term potential of common varieties and blends of species [wheat (Triticum aestivum L.), triticale (xTriticosecale), and oats (Avena sativa L.)] in an irrigated production system. Eleven entries were tested in at least 3 years, including exceptionally wet (2005) and dry (2006) years. In any given year, all crops yielded greater than 2.5 tons of DM, and entry mean annual yields ranged from 4.0 to 5.3 ton DM/acre over the study period. Triticale or blends containing triticale yielded more wet forage than wheat alone. In general, nutritive value of wheat was greater than that of triticale and blends. One triticale entry exhibited similar DM yields and forage quality as those of the wheats. Under irrigation, small grains have the potential to produce acceptable yields of nutritious forage in between summer crops for feeding operations in the region. While wheat may yield less tonnage, it gives greater market flexibility and may better fit into double cropping systems because of its earlier maturity than triticale.

Introduction

Small-grain crops are used extensively in eastern New Mexico and West Texas for various types of forage production and animal feeding operations. Due to the large influx of dairy facilities into New Mexico and the Texas Panhandle and the extent to which these dairies utilize preserved feeds, there is a need for information on performance of small-grain forages to assist in management of the cropping systems. Small grains used to the greatest extent in the region for hay, silage, and greenchop are wheat (Triticum aestivum L.), triticale (xTriticosecale) and oats (Avena sativa L.). All of these species have the potential to fill gaps between summer crops to supply year-round, high-quality feed and to meet the constant and high nutritional demands of lactating dairy cows (2,14). Growing the crops with the intent to sell to nearby dairies gives area farmers a potentially more profitable and less water consuming (12) alternative to grain harvest, depending on comparative crop market values. Small grains also serve as excellent cover crops that help prevent soil erosion and take up significant amounts of soil nitrogen (11) and phosphorus (3). Nitrogen uptake is particularly important in green water, land application practices common with dairies. Interest in small-grain crops will likely continue to increase as more feeding operations move into the southern High Plains and as corn prices limit profitability of animal feeding operations in the US. Research on small grains harvested as forage is limited yet very necessary in the region. Questions persist regarding species and varietal suitability and small-grain management in semi-arid irrigated systems. The objectives of this research were to investigate the long-term performance of certain small grains and blends of species for both yield and nutritive value and to assess their potential for adequate forage production for use in large-scale dairy operations.

Testing Relative Performance of Small-Grain Forage Types

Annual mean data (15) for this study were selected from variety performance evaluations conducted at the New Mexico State University Agricultural Science Center at Clovis (103°12’W, 34°35’N, elev. 4435 ft) from 2004 to 2008 (harvest years) (Table 1), the annual results of which are available at clovissc.nmsu.edu/variety-trials.html or by contacting Mark Marsalis at 575-985-2292 or marsalis@nmsu.edu. Soil type was an Olton clay loam (fine, mixed, superactive, thermic Aridic Paleustoll). Eleven varieties or blends were selected for long-term analysis with a minimum of three years of testing (Table 2). Maximum duration of testing was five years for certain entries. Trials were planted in the fall of years 2003 to 2007. All 11 entries were planted in 67-ft² plots under furrow irrigation (2003) or center pivot irrigation (2004-2007). Individual plots consisted of 11 rows, 6.25 inches apart and 10 feet long. Plots were planted at rates ranging from 90 to 100 lb/acre (depending on year) with a plot drill.

Table 1. Crop inputs for each year of small-grain forage performance tests (2004-2008) conducted at NMSU Agricultural Science Center at Clovis, NM.

Procedures/inputs		2004	2005	2006	2007	2008
Precipitation (inches)		10.0	16.0	2.4	9.0	2.9
Irrigation (inches)		21.0	10.0	11.5	7.2	15.0
Planting date		16 Sept	13 Sept	24 Oct	25 Oct	25 Oct
Growing degree days		2838	2438	2396	2016	2076
Fertilizers	N (lb/acre)	123	100	158	153	173
	P (P₂O₅, lb/acre)	20	40	28	88	60
	S (lb/acre)	13	55	15	0	7
Herbicides	Glyphosate (24 oz/acre)				X*
	Dicamba (4 oz/acre)				X
	2,4-D (8 oz/acre)	X		X	X	X
	Trifensulfuron-methyl (0.3 oz/acre)	X
Insecticides	Chlorpyrifos (16 oz/acre)	X	X	X		X

* indicates that the chemical was used in that year.

Table 2. Dry forage yields (ton/acre) of small-grain types used in long-term (2004-2008) performance studies at NMSU Agricultural Science Center at Clovis, NM.

Variety /blend	Species^x	2004	2005	2006	2007	2008	SD^y
SlickTrit	T			4.4	5.1	5.1	0.40
Tamcale 5019	T		5.5	4.1	3.5	3.7	0.90
Triplecale	T	4.8	5.1	4.1	4.7	4.3	0.40
Pounds Plus B	T/W/O	5.4	5.7	3.8	4.2	4.3	0.82
Master Blend	T/W/O	5.1	5.7	3.7			1.03
Maximizer A	T/W	5.7	5.9		4.0	4.0	1.04
Maximizer B	T/W	4.7	5.3	3.4	3.8	4.6	0.76
TAM 111	W	4.9		3.2	3.3		0.95
Dumas	W	4.5	6.1	2.9	3.5		1.40
Cutter	W	4.9	5.8	2.9	3.3		1.36
Jagalene	W	4.9	5.7	2.6	3.0		1.50
LSD, 0.05		1.2	0.6	0.5	0.9	0.7

^x O = oat; T = triticale; W = wheat.

^y SD = Standard deviation of the means of years tested.

Fertilizer applied varied from year to year depending on soil nutrient analysis (Table 1) and was based on a 90 bu/acre grain yield goal. Nitrogen applications (28-0-0) were split between planting (1/3 total N) and topdressing prior to jointing in the spring (2/3 total N). Herbicides were used to control weeds at various times during the season (or pre-plant), and these included glyphosate, dicamba, 2,4-D, and trifensulfuron-methyl/tribenuron methyl. Chlorpyrifos was used in all years except 2007 to control aphid populations. Total in-season water (precipitation + irrigation) amounts were reduced after 2005 and planting was delayed from September to October because of excessive vegetative growth and lodging experienced in 2004 and 2005 (Table 1). Irrigations were based approximately on regional potential evapotranspiration data from nearby weather stations and were adjusted during precipitation events. Precipitation during the tests was quite variable, and 2006 was considered exceptionally dry; in contrast, 2005 received a particularly high amount of precipitation compared to long-term normal amounts during the growing season (Table 1).

The small grains were managed for a one-cut, greenchop/silage/hay-oriented harvest in spring of each year. Harvests began in April with the earliest maturing species (wheat) and continued through May. Plants were harvested at boot stage (Feekes scale, 10.0 to 10.3; Zadoks scale, 45 to 53) for optimization of both yield and forage quality (7). All plots were harvested with a sickle-bar mower set at a height of 2 inches, and total plot weights were obtained to estimate yield on both a wet forage and DM basis. A subsample was taken from each plot for drying to determine DM content and later forage quality analysis. Samples were oven dried at 55°C for 48 h.

Once dry, collected material was weighed to estimate yield on a dry basis and ground to 1 mm using a Wiley Mill (Comeau Technique Ltd., Vandreuil-Dorion, Quebec, Canada) and stored at room temperature for further analysis. Ground forage from harvest was analyzed by near-infrared (NIRSystems Inc., Silver Spring, MD) absorption techniques at the University of Wisconsin Soil/Forage Analysis Laboratory, Marshfield, WI [National Forage Testing Association certified laboratory, (6)], to predict levels of acid detergent fiber (ADF), neutral detergent fiber (NDF), neutral detergent fiber digestibility (NDFD), and crude protein (CP). Net energy for lactation (NE_L) was calculated using equations described in NRC (9).

Annual mean yield and nutritive value data were analyzed with variety nested within forage type (wheat, triticale, wheat-triticale blend, or wheat-triticale-oat blend) using SAS PROC MIXED ANOVA (8). Year was considered the replicate and, along with residual mean squares, was considered random and appropriately used by PROC MIXED as denominators for tests of significance (SAS Institute Inc., Cary, NC). Least significant difference values were generated using the LSMEANS statement with the PDIFF option to determine where differences occurred among forage type and variety within type. Because of slight differences in variances used by the LSMEANS statement for pairwise comparisons, the largest calculated LSD was used to separate means in this study.

Yield and Nutritive Value

Mean yield and nutritive value results from 2004-2008 are presented in Tables 2, 3, and 4. Wet forage yields are presented because of their importance to producers and consultants that grow or manage silage crops in the region and due to the pricing of silage crops based on wet yields. Large variation in precipitation from one year to the next (Table 1) likely affected DM yields of the small grains in any given year (Table 2); and it appears that environment and total water applied have some impact on the yield ranking of species from year to year. For example, in 2005 when water applied exceeded 26 inches, wheat yielded more DM numerically than the two triticales grown. In contrast, triticales performed better than wheats in 2006 when total water was limited to under 14 inches (Table 2). With the exception of TAM 111, wheat DM yields were more variable (SD > 1.35) from one year to the next than those of triticale (Table 2). Dumas, Cutter, and Jagalene, for instance, performed exceptionally well in 2005 (5.7 to 6.1 ton DM/acre), but had considerably lower yields in 2006 and 2007, suggesting that wheat may be more competitive in high rainfall years or under high irrigation. Variety likely plays a large role in performance from one year to the next. In addition, planting date [and subsequent growing degree days, GDD, (10), Table 1] may have affected DM yields, particularly in wheat and blends as yields were higher in 2004 and 2005 when crops were planted in mid-September than those planted in late October from 2006 to 2008 (Table 2). When grouped by species type, dry and wet yields over the study period averaged 4.5 and 20.2 ton/acre, respectively (Table 3). Dry forage produced was not different (P > 0.10) among the types and ranged from 4.13 to 4.75 ton/acre. This is consistent with previous work showing similar DM yields between wheat and triticale in early spring (10). However, wheat yielded less (P < 0.05) wet forage than triticale or blends containing triticale (Table 3). In addition, wheat alone was drier at harvest than triticale and blends, which resulted in less wet forage. This is not surprising considering that these wheats were bred primarily for grain purposes; however, they are commonly used as dual-purpose crops with the potential to be utilized as forage and grain. Wheat also gives the grower greater flexibility at harvest where harvest method (i.e., grain or forage) can be adjusted to accommodate the most profitable market and returns. Triticale marketability is limited to forage production mainly and to a lesser extent seed production; triticale grain is not highly sought after because of its poor milling properties. On average, triticale matures later than wheat (4,6). In this study, ‘Triplecale’ and ‘Tamcale 5019’ were the earliest maturing entries tested in more than 3 years (Table 4); however, yields were comparable to or greater than other varieties and blends. In contrast, SlickTrit was high yielding, but late maturing. Again, this suggests large cultivar variation, and relative maturity should be taken into consideration when determining which species are to be grown for different types of production systems.

Table 3. Forage yields and quality of small-grain types used in long-term (2004-2008) performance studies at NMSU Agricultural Science Center at Clovis, NM.

Species^x	Dry forage^y	Fresh forage	Moisture at harvest	Crude protein	ADF	NDF	NDFD	NE_L
Species^x	(ton/acre)		(%)	(% of DM)			(% NDF)	(Mcal lb)
T	4.8	22.8	79.2	16.2	32.3	52.2	70.4	0.670
T/W/O	4.6	21.1	78.0	15.8	31.7	51.6	70.2	0.673
T/W	4.5	20.4	77.8	16.2	32.4	52.6	69.5	0.667
W	4.1	16.5	75.2	16.4	28.8	47.8	72.6	0.698
LSD, 0.05	ns	2.2	2.2	ns	1.6	1.8	2.1	0.017
LSD, 0.10	0.42	1.8	1.8	ns	1.3	1.5	1.7	0.014

^x O = oat; T = triticale; W = wheat.

^y Data are least squares means of 2 to 4 varieties and/or blends and number of years each was tested; means may be different than those calculated from averaging values presented for each variety or blend in Table 2.

Table 4. Forage quality of small-grain varieties and blends used in long-term (2004-2008) performance studies at NMSU Agricultural Science Center at Clovis, NM.

Although wheat alone produced low wet yields, it was characterized by superior nutritive value to the triticale and blends: higher NE_L and NDFD; and lower ADF and NDF (Table 3). Nutritive value measurements in this study also were consistent with work conducted (6) in which small-grain forages were harvested at boot stage and, as with yield, variability across years was very similar among species and varieties (data not shown). Crude protein among the types was not different (P > 0.10) (Table 3). Fiber proportions (ADF, NDF) increased with larger yields (Table 4). Although all varieties were harvested at the same maturity stage, often large yields result in proportionately less protein and increased fiber. Within any given year, the general trend was that as DM yield increased, CP and NE_L were reduced and fiber proportions increased (data not shown). This occurrence remained true over the long term for NE_L, with the exception of TAM 111 which was characterized by both low yields and NE_L over the 3 years tested (Table 4). In addition, there was a strong trend of lower fiber digestibility (NDFD) associated with higher yields (1) (Table 4). ‘Tamcale 5019’ exhibited excellent forage quality (high CP and NE_L, low ADF and NDF) over the 4 years it was tested. Nutritive value of all crops (harvested at boot stage) was superior to those reported by NRC (9) for wheat and triticale forage cut at heading or later. The triticale cv. ‘SlickTrit’ has performed well consistently with respect to total wet (24.8 ton/acre) and dry (5.3 ton/acre) yield over 3 years; however, low CP and NE_L and high fiber limit its nutritive value (Table 4). This variety grows particularly tall (> 4 ft) and has exhibited similar characteristics in other regional on-farm trials and demonstrations. Nutritive value of high yielding, low quality triticale may be improved by legume additions to the system or blending with other small grains (5,6). Lauriault and Kirksey (6) found that sowing winter pea [Pisum sativum subsp. arvense (L.) Poir] with wheat or triticale improved forage nutritive value (3 to 4% increase in CP and 0.05 Mcal/lb NE_L, both of which are considerably higher than the LSD’s for those components in this study) at the expense of yield (0.5 ton/acre).

Although yield is maximized at later growth stages (i.e., milk to soft dough), cutting at earlier stages allows for a balance of good yields and nutritive value (1,2,13). Considering the high nutritional needs of dairy cattle in the region and the common practice of double cropping with corn or sorghum, an early cutting of forages was deemed most appropriate for the area.

Conclusions

Large amounts of good quality forage can be produced with small grains under irrigation to meet the high nutritional demands of the expanding dairy industry. While excessively dry years may lead to significantly lower yields and there will be some difference in the ranking of the species tested from year to year, long-term results indicate that in most years adequate yields and nutritive value of all wheat, triticale, and blends can be obtained. Triticale appears to be more consistent from year to year. In general, triticale (and blends containing it) produces more tonnage and lower quality forage than wheat; however, this is variety specific and some triticales may be grown with similar quality to wheat. Producers should select high yielding varieties within the species they decide to plant. Although summer crops (i.e., corn, sorghum) yield more forage per acre, small-grain forages have the added benefit of a grazing option early in the growing season that adds value to the system. Cool-season small grains fit well in double cropping systems because of their early maturity relative to other species, and they provide a potentially cost-effective supplement to corn in years when market prices make purchasing large quantities of corn silage uneconomical.

Acknowledgments

This research was supported by the New Mexico Agricultural Experiment Station. The authors gratefully acknowledge the technical and field assistance of Aaron Scott, Bryan Niece, Gilbert Lucero, Kenneth Phipps, Valerie Pipkin, and Christie Werner during the project.

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