A field lysimeter study with bare ground and five different ground covers was established to evaluate the effect of forage grasses on the fate and transport of two herbicides in leachate. The herbicides were atrazine (ATR; 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) and isoxaflutole [IXF; 5-cyclopropyl-4-(2-methylsulfonyl-4-trifluormethyl-benzoyl)isoxazole], which has the commercial ...

Seedling establishment is a critical phase in pasture management. Knowledge of the seedling development of new forages is necessary to develop management practices and recommend species mixtures for pasture seedings. We compared seedling growth and development of prairiegrass (Bromus willdenowii Kunth = B. catharticus Vahl), grazing bromegrass (B. stamineus Desv.), and orchardgrass (Dactylis gl...

Soil organic C (SOC) and total N (TN) contents play a crucial role in sustaining agricultural production systems. Short-term ( 10-year) management effects on SOC and TN dynamics are often complex and variable. Three experiments were conducted to evaluate short-term tillage and cropping system effects on SOC and TN within the 0–30 cm soil depth across Iowa. The first experiment with no-tillage a...

Meadow bromegrass (Bromus riparius Rehm.) has gained interest as a highly productive pasture grass that can be used under management intensive grazing with limited irrigation. In 1999, 28 cloned parents and half-sib families of meadow bromegrass were each planted in a randomized complete block design to evaluate genetic variation of meadow bromegrass for dry matter yield (DMY) (Harvests 1 to 6)...

A 2-gram fresh weight inoculum of bromegrass (Bromus inermis Leyss. culture BG970) cell suspension culture treated with 7.5 x 10(-5) molar abscisic acid (ABA) for 7 days at 25 degrees C survived slow cooling to -60 degrees C. Over 80% of the cells in ABA treated cultures survived immersion in liquid N(2) after slow cooling to -40 or -60 degrees C. In contrast, a 6-gram fresh weight inoculum onl...

A field experiment was conducted to evaluate the effects of two nitrogen levels (N: 0,100 kg ha -1 ) and four phosphorus levels (P: 0, 60, 90, 120 kg P2O5 ha -1 ) on smooth bromegrass (Bromus inermis Leyss.) seed quality by measuring germination, mean germination time (MGT), protein and phosphorus contents, acid phosphoesterase (APT) and antioxidant enzymes activities, hydrogen peroxide (H2O2) ...

Alfalfa (Medicago sativa L.) persistence and forage and cow-calf production were evaluated on pastures containing smooth bromegrass with or without grazing-tolerant or hay-type alfalfa cultivars rotationally stocked in either a season-long or complementary system. In 1997, six 2.02-ha pastures were seeded with smooth bromegrass, a mixture of a grazing-tolerant alfalfa (Amerigraze variety) and s...

Although cool-season grasses increase DM yield at high N rates, N recovery (kg plant N kg 1 N applied) Nitrogen removal by cool-season grasses may aid in capturing exgenerally declines as N rate increases. Ramage et al. cess N from animal confinement operations or phytoremediation. (1958) reported fertilizer N recovery of 0.59 and 0.59 kg Limited information exists on the N dynamics of these gr...