Tag: 2019

Nicole Fiorellino, Extension Agronomist
University of Maryland

Dairy farmers are constantly looking for sources of forage to meet their feed needs. One source that many of this region’s dairy farmers utilize is the fall planting of cereal grains that are green-chop harvested the following spring. Among the cereal species used for this purpose are rye, triticale, barley, and wheat. Per the Maryland Cover Crop Program guidelines, cereal grains planted as a cover crop prior to November 5 and suppressed via green-chop in the spring are eligible for the grant payment for participation in the Cover Crop Program. In addition, per the Nutrient  Management Regulations, a fall application of dairy manure is allowed to a field planted to a cereal cover crop.

Planting a cereal cover crop that will be green chop harvested fits well into the crop rotation used by many dairy farmers. The scenario that many follow is to plant the cereal cover crop following harvest of corn silage. Prior to planting the cover crop, an application of manure is made to the field. The subsequent planting of the cover crop provides incorporation of the manure into the soil. The fall and spring growth of the cover crop is supplied nutrients from the manure. At the same time, the cover crop provides protection to the soil from loss of nutrients via leaching and/or erosion. The objective of this study was to evaluate select varieties of cereal species for cover crop performance and forage production and quality.

Cereal varieties (17) representing two species (rye and triticale) were evaluated at Central Maryland Research and Education Center – Clarksville Facility. Three replications for each entry were planted using a randomized complete block experimental design. Planting date was October 10, 2018. The 3’ X 18’ plots were planted with a small plot planter with 6-inch spacing between each of the 7 rows. The germination percentage for each entry was used to calculate the seeding rate needed to establish 1.5 million seedlings. Good stands were established by late fall.

In order to compare forage quality among the entries that headed over a period of two weeks, the timing of the spring biomass harvest was when the entries had reached late boot to early heading stage of development. The two rye varieties were harvested on April 23, while the triticale varieties were harvest on either May 1 or May 6, basing on heading date (Table 1). Each harvest sample was collected by cutting the plants just above ground-level from three center rows of each plot from an area 2.5 feet in length and from two areas within the plot. The samples were placed into cloth bags and dried using a forced air dryer set at 60 C where they remained until sample water content was zero. Each sample was weighed and is reported as pounds of dry matter production per acre (Table 1). Each of the dried samples was ground through a 20-mesh screen using a large plant grinder. For each location, the ground biomass samples were sent to Cumberland Valley Analytical Laboratory for standard forage quality analysis.

Cover crop performance is measured by amount of biomass produced and the concentration of nitrogen in the biomass. These two factors were used to estimate nitrogen uptake (Table 1). There was no significant difference in nitrogen uptake among the varieties tested. A number of forage quality characteristics for these cereals was measured (Table 1). The descriptions of the various quality characteristic are described here and in the footnotes at the bottom of Table 1. Crude protein (CP) is the nitrogen content of the forage, with higher protein representing better feed quality. This value was used to calculate nitrogen uptake of each variety (Nitrogen content = % CP/6.25). Both rye varieties had significantly greater CP than the overall mean, with one triticale variety having significantly less CP content than the overall mean. Both rye varieties also had rumen degradable protein (RDP) content significantly greater than the overall mean.

Neutral and acid detergent fiber (NDF. ADF) are measures of feed value and represent the less digestible components of the plant, with NDF representing total fiber and ADF representing the least digestible plant components. Low NDF and ADF values representing increased digestibility; ideally NDF values should be <50% and ADF values should be <35%. One triticale variety had significantly lower NDF and ADF values than the overall mean, representing a digestible triticale variety. This same variety also had significantly higher total digestible nutrients (TD), net energy for lactation (NEL), relative feed value (RFV), and nonfiber carbohydrates (NFC).

The characteristic that best captures the overall forage quality performance is Relative Feed Value (RFV). A RFV of 100 is defined as the forage value that full bloom alfalfa would have. Two triticale varieties had significantly higher RFV than the overall average but both rye varieties also had high RFV values, though not significantly different than the overall mean. Though, none of these green-chop cereal forages are considered to be adequate as a stand-alone feed for a dairy operation, they can supply a source of forage used in a total mixed ration at the time of year when feed supply may be running short. When this forage benefit is added to the environmental benefit that is gained, planting winter cereal cover crops on a dairy farm can be a win-win decision.

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