An Agronomic and Economic Analysis of Annual Ryegrass Management Practices in North-Texas Soybean Production

An analysis of the effect of ryegrass cover crop on no-till soybean yield, grain density, and height; and profitability of harvesting ryegrass for forage. Annual ryegrass is a cool-season annual bunchgrass, which due to its high palatability and digestibility is valuable for forage. Grazing cover crops is economically viable when the returns offset establishment costs without reducing crop yields. Six ryegrass management practices prior to planting soybean were evaluated: volunteer ryegrass as a cover crop, ryegrass forage harvested for hay, ryegrass forage grazing simulation, and three different herbicides applications that vary in timing (December, February, and March application). All forage and cover crop plots were terminated with Glyphosate or Paraquat two weeks prior to planting soybeans. There were no statistical differences in soybean yields, soybean height, and soybean grain density between annual ryegrass cover cropping and herbicide treatments. The results also indicated that ryegrass forage can produce up to 2,741 kg ha-1 of dry matter that if sold as hay can generate a profit between $230 and $244 ha-1 . Similarly, if land is leased for grazing, ryegrass could generate a profit of $63 ha-1 if its dry matter production is 1,006.70 kg.

本研究分析了黑麦草覆盖作物（cover crop）对免耕（no-till）大豆产量、籽粒密度及株高的影响，以及收割黑麦草用作饲草（forage）的经济效益。一年生黑麦草（Annual ryegrass）属于冷季型一年生丛生禾草，因其适口性佳、消化率高而成为优质饲草来源。当饲草收益抵消种植成本且未降低主作物产量时，覆盖作物放牧具备经济可行性。本研究评估了大豆播种前的6种黑麦草管理措施：以自生黑麦草作为覆盖作物、收割黑麦草制作干草（hay）、模拟黑麦草饲草放牧，以及3种施药时机不同的除草剂处理（分别于12月、2月和3月施药）。所有饲草及覆盖作物小区均在大豆播种前两周，使用草甘膦（Glyphosate）或百草枯（Paraquat）进行灭杀处理。一年生黑麦草覆盖作物处理与除草剂处理之间，大豆产量、株高及籽粒密度均无统计学显著差异。研究结果同时显示，黑麦草饲草的干物质产量可达2741 kg·ha⁻¹，若将其作为干草售卖，每公顷可获得230至244美元的利润。同理，若土地被租赁用于放牧，当黑麦草干物质产量为1006.70 kg·ha⁻¹时，每公顷可获得63美元的利润。