The effects of grass maturity on the mean retention time of liquid and particles, digestibility and duodenal nutrient flows were measured by feeding second cuts of perennial ryegrass to 3 fistulated lactating dairy cows over 2 successive periods (late June and mid-July, 28 and 49 d regrowth, respectively). Fresh forage was given ad libitum with 12% (dry matter (DM) basis) concentrate. The incre...

Photosynthetic (14)CO(2) fixation, [(14)C]glycolate formation, and the decarboxylation of [1-(14)C]glycolate and [1-(14)C]glycine by leaf mesophyll protoplasts isolated from isogenic diploid and tetraploid cultivars of ryegrass (Lolium perenne L.) were examined. The per cent O(2) inhibition of photosynthesis in protoplasts from the tetraploid cultivar was less than that of the diploid line at b...

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous, recalcitrant, and potentially carcinogenic pollutants. Plants and their associated rhizosphere microbes can promote PAH dissipation, offering an economic and ecologically attractive remediation technique. This study focused on the effects of different types of vegetation on PAH removal and on the interaction between the plants and their as...

Ryegrass is a highly nutritious grass that can be utilized for grazing or production of baleage, haylage, or hay. In contrast to many regions of the world that are suitable for production of perennial ryegrass, annual ryegrass varieties are best suited for use in the Southeast US. When properly managed, annual ryegrass provides moderate concentrations of degradable protein. Annual ryegrass is h...

Sulphate leaching losses may reduce the long-term possibility of maintaining the S supply of crops in low input farming systems. Sulphate leaching and S balances were investigated in an organic dairy/crop rotation (barley [Hordeum vulgare] → grass-clover [Lolium perenne/Trifolium repens] → grass-clover → barley/pea [Pisum arvénse] → winter wheat [Tritucum aestivum] → fodder beet [Beta vulgaris]...

In a feeding trial with sheep, four animals each were fed one of the three roughages (perennial ryegrass (PR), meadow fescue (MF) and red clover (RC)) or one of the four different mixtures (g/day 250 : 250 : 250, 375 : 75 : 300, 525 : 187.5 : 37.5 and 75 : 525 : 150, respectively) of those three roughages, both with and without the inclusion of 100 g of beeswax-labelled barley. Further, four sh...

The effect of nitrogen (N) stress on the pool system supplying currently assimilated and (re)mobilized N for leaf growth of a grass was explored by dynamic ¹⁵N labeling, assessment of total and labeled N import into leaf growth zones, and compartmental analysis of the label import data. Perennial ryegrass (Lolium perenne) plants, grown with low or high levels of N fertilization, were labeled wi...

Polymer coated urea (PCU) is a N fertilizer which, when added to moist soil, uses temperature-controlled diffusion to regulate N release in matching plant demand and mitigate environmental losses. Uncoated urea and PCU were compared for their effects on gaseous (N2O and NH3) and aqueous (NO3(-)) N environmental losses in cool season turfgrass over the entire PCU N-release period. Field studies ...

Alternative stable states have long been thought to exist in natural communities, but direct evidence for their presence and for the environmental switches that cause them has been scarce. Using a combination of greenhouse and field experiments, we investigated the environmental drivers associated with two distinctive herbaceous communities in coastal ecosystems in New Zealand. In a mosaic unre...

The effects of soil water deficit and interspecific plant interaction were studied on the dry matter (DM ) yield of white clover and ryegrass and on the morphogenesis of white clover. Plants were grown either: (1) individually (no interaction); or in a mixture of equal plant numbers with either (2) just shoot interaction, or (3) both shoot+root interaction. Plants were subjected to soil water d...