Use of Dual-Purpose Winter-Grain Cover Crops as Emergency Forage and for Management of High Soil Phosphorous in Manured Fields

Abstract

Dual-purpose cover crops can cycle nutrients on dairy farms while providing additional quality forage. However, questions remain regarding the crop species best suited to this function. A two-year field experiment with five small-grain winter cover crops, including rye (Secale cereale), wheat (Triticum aestivum), and three triticale varieties (×Triticosecale varieties), was conducted on an active dairy farm. The rye produced the highest yield at 4612 kg ha−1, followed by the forage varieties of triticale, which averaged 4004 kg ha−1, whereas the wheat and one nonforage triticale produced only 2950 and 2987 kg ha−1, respectively. The wheat had the highest crude protein (CP) at 11%, and a relative feed value (RFV) of 132, and it had the greatest milk-production potential, which was 1729 kg milk/Mg of forage. Yet, the rye (CP: 10.4%; RFV: 112) had the greatest milk-production and economic potentials per hectare due to the high forage yield, valued at USD 714 ha−1, whereas the nonforage triticale had the least economic value (USD 326 ha−1), despite its high forage quality (CP: 9.5%; RFV: 120). The forage triticale varieties were intermediate performers compared with the rye and wheat on a yield and quality basis. Mirroring the yield, the rye also removed the most nitrogen (77.3 kg ha−1) and phosphorus (20.8 kg ha−1). The species differences were found to be contingent on the manure application. The results of this experiment suggested that winter rye is the most efficient cover crop for harvesting and nutrient-recycling purposes.