The present study investigated the effect of a perennial lucerne and phalaris pasture, or annual pasture with lucerne hay and a range of supplements provided as pellets (700 g/day) on Vitamin E and fatty acid content of skeletal muscle and oxidative stability of lamb meat post-farm gate. Treatments were lambs grazing perennial pasture only (PP); lambs grazing annual pasture with lucerne hay and oat grain pellet supplement (AP); AP with cracked flaxseed (AP+FS); and AP with flaxmeal (AP+FM). After 7 weeks of feeding, lambs were slaughtered after an overnight fast. At 24 h post-slaughter, samples of muscle longissimus lumborum (LL) were collected for determination of fatty acid profile and antioxidant status, as measured by Vitamin E content. Samples were also collected for retail colour assessment of fresh meat at 24 h, 48 h, 72 h and 96 h of post-slaughter. Vitamin E content of the LL from lambs grazing PP was higher (5.9 v. 3.4 mg a-tocopherol/kg, P < 0.01) than that of lambs grazing other treatments. Long-chain n-3 and total n-3 fatty acid contents in the muscle were similar among treatment groups and adequate to claim as a source of n-3. Inclusion of oat grain at 245 g (AP) or at 175 g with flaxseed (AP+FS) or 175 g with flaxmeal (AP+FM) per day in the diet of lambs increased the linoleic acid content (P < 0.05) and the ratio of n-6 : n-3 (P < 0.007) in the LL, compared with lambs grazing PP. Oxidative stability of fresh meat evaluated by retail shelf life (retention of redness) and formation of lipid oxidative substance showed no differences among treatment groups and, as indicated by redness (a*-value) over a 96-h display, all values were within the range (>9.5) for quality meat over the time frame used in the present study. The results provided some evidence that inclusion of PP in the diets of lambs during dry seasons (late summer to autumn) is an effective tool of improving the Vitamin E content of muscle tissues at slaughter.

Summary. A long-term experiment in north-eastern Victoria has been regularly monitored for wheat yield responses to a range of lime and fertiliser treatments, and the soil sampled for acidity attributes. Substantial grain yield increases have been consistently obtained over a period of 12 years with a single lime application. Lime applied at 2.5 t/ha in 1980 was still providing yield increases of 24% with an acid-tolerant wheat (Matong, 1992 season) and 79% with an acid-sensitive wheat (Oxley, 1993 season) relative to no lime treatment. The 2 wheat cultivars responded differently to phosphorus fertiliser, with the acid-sensitive wheat less responsive to phosphorus fertiliser in the absence of lime. The use of a regular lime application applied as a fertiliser (125 kg lime/ha) with the wheat seed gave only a small grain yield increase (8% Matong, 16% Oxley), despite 1 t/ha of lime applied over the 12-year period. Liming the soil at a rate of 2.5 t/ha (1980) initially raised the soil pH by about 1.0 unit and removed most soluble aluminium (0–10 cm). However, after 12 years of crop–pasture rotation after the initial 2.5 t lime/ha treatment the soil pH had declined by 0.7 of a pH unit and exchangeable aluminium was substantially increased, almost to levels prior to the initial application of lime. Given the continued yield responsiveness obtained following the initial application of lime, this practice, rather than regular applications of small amounts of lime, is recommended for wheat production on strongly acidic (pHw < 5.5) soils in south-eastern Australia.

Summary. Wheat ( Triticum aestivum L.) seed was grown at 2 locations differing in phosphorus (P) status (low and high) in north-eastern Victoria (36°S, 146°E), with applied superphosphate (kg P/ha: 0, 12, 24, 100 and 200), to produce seed of different P content. This seed was used in field and glasshouse experiments in 1993 and 1994 to investigate the effects of seed source and P content on the growth and yield of wheat. Wheat seed grown at the low P status site was smaller than seed grown at the high P status site, irrespective of the amount of applied P. Seed from the low P status site produced less early dry matter in both field and glasshouse experiments in 1993, but there was no effect of seed source on grain yield in either experiment. High seed P content either had no effect or reduced seedling emergence in the field experiments. In the glasshouse, low P content in seed from the low P status site resulted in reduced emergence. Increases in dry matter production and grain yield with higher seed P content were only observed in the drought season of 1994. Application of P resulted in increased emergence, dry matter production and grain yield at most seed P content levels but there were no significant interactions between seed P content and applied P. Application of N did not affect dry matter production in either year, but increased grain protein in both years and grain yield in 1993. Seed from low P status environments can affect early seedling growth but in average growing seasons, or in glasshouse conditions, wheat growth compensates so that differences in grain yield are not observed. However, in order to avoid risk of poor early seedling growth and possible yield penalties when the crop is stressed, wheat seed should be collected from adequate soil P status sites.