The effects of sowing time, sowing technique and grazing on tall fescue (Festuca arundinacea Schreb.) establishment

Abstract

The effects of sowing time (autumn and spring) and technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial seeding), on the establishment of tall fescue into a weed infested pasture on the Northern Tablelands of New South Wales were examined. A pre-sowing herbicide treatment was included in the 2 direct drilling treatments, and heavy pre-sowing grazing was used in the autumn sowing. The design used 38 plots of 0.12 ha, analysed as 2 separate, complete block experiments, with some common treatments. Tall fescue establishment, 120 days after the autumn sowing, averaged 48 seedlingslm2 on the inverted T treatment (16% establishment). Establishment was improved by 63%, to 78 seedlings/m2, with herbicide and 46%, to 70 seedlings/m2, by heavy grazing. These effects were additive, giving 105 seedlings/m2 for the combined treatments. Only 52 seedlings/m2 established on the triple disc treatment with heavy grazing and herbicide, while establishment on the cultivated seedbed was not different from the inverted T (93 seedlings/m2). There was no establishment after the aerial seeding at either sowing. Fescue establishment showed the same trends in the spring sowing, with 140 seedlings/m2 on the inverted T treatment with pre-sowing herbicide, which was higher than the establishment of 107 seedlings/m2 on the cultivated seedbed. The fescue yield, 18 months after the autumn sowing, was highest in the autumn sown, inverted T treatment with pre-sowing herbicide and heavy grazing (123 kg/ha). In the spring sowing, fescue was recorded only on the cultivated treatment (84 kg/ha) and on the inverted T treatment with pre-sowing herbicide (39 kg/ha). These results show that tall fescue can be re-established into weed dominated pastures on the Northern Tablelands with direct drilling, in either autumn or spring, and that heavy, pre-sowing grazing and herbicide increase fescue establishment.