Pasture species investigations - wheat belt (May, 1975)

Results from trials comparing the growth and persistence of a number of annual pasture legumes are presented in this report. Rainfall conditions during the year are described briefly and a table of annual and growing season rainfall at relevant centres is appended. The experiments are grouped as follows according to average annual rainfall:- Zone A - Average annual rainfall \u3e 400 mm Zone B - Average annual rainfall 345 - 400 mm Zone C - Average annual rainfall \u3c 345 mm and then, further, on soil type. District Rainfall, 1974. 71LG16,, 72LG3, 74KA3, 70OTS2, 72TS5, 70NA3, 71TS22, 74NO3, 70ME4. The early break, with good rainfall continuing through most of the growing season, provided optimal conditions for most wheat belt trials. These conditions were in direct contrast to the dry years of the late 1960\u27s and early 1970\u27s. In 1974, legume growth on droughty deep sands should have been at its best. Serradella responded at Kukerin in direct relationship with earlier heavy dressings of potash. West of Three Springs, serradella and Tornafield medic stayed a little ahead of Harbinger medic and well ahead of Daliak sub. clover and rose clover. On deep sands at Marchagee and Arrino, subterranean clover was the only species worth considering. The failure of Eragrostis curvula to persist through the dry 1973-74 summer after good germination in late winter, indicates a need for more work on the establishment of this grass on deep sands. The low yields of dry matter at Tincurrin do not offer much incentive for such work, but Eragrostis, lupins and serradella probably give the best chance of pasturing the grossly infertile, erodable sands. Under favourable conditions, Geraldton sub. clover continued to show its versatility and aggressiveness. On an alkaline loamy sand at Lake King, waterlogged for periods during the winter, Dwalganup, Geraldton and Northam A produced more dry matter than a wide range of other pasture legumes. At Walgoolan, Geraldton maintained better than 503 content in mixtures with other sub. clover cultivars sown in 1970, while in a trial at Marchagee there was evidence of gradual, aggressive regeneration of Geraldton from a sparse pasture sown before the trial. Only two new legume species trials were planted in 1974, and these were not successful. Trial 74KA3, east of Katanning, demonstrated the need for timely planting. Had seed been available on time, the trial would have been planted before the onset of heavy rains and would have given better results. The failure of Tornafield and Harbinger on 74N03 should not weight the record unduly against these medics; :they have never excelled on clay loams, and they were sorely harassed by redlegged earthmite. The medics will not be replanted, but Northam A and Geraldton will be observed in 1975.