PHOSPHORUS-NUTRITION OF LARGE-SEEDED CHICKPEA CV MACARENA (CICER-ARIETINUM) IN THE ORD RIVER IRRIGATION AREA, WESTERN-AUSTRALIA

The phosphorus (P) nutrition of large-seeded chickpea (Cicer arietinum ) cv. Macarena grown on Cununurra clay in the Ord River Irrigation Are a was studied in field trials and by sampling commercial crops. Respon se to applied and residual P on a previously uncropped site (site 1) w as examined over 2 growing seasons and to applied P on a site with a h istory of cropping (site 2) in 1 season. At site 1, yield increased wi th application of up to 50 kg P/ha in the first year and 100 kg P/ha i n the second year. There was no significant response in the second yea r to the P applied in the previous season, probably because of rapid f ixation of P in Cununurra day. At site 2, with a residual soil P level of 24 mu g/g (HCO3), no growth response to applied P was observed. Th e survey of commercial crops included determination of P in soil, foli age, and seed, and the recording of phosphatic fertilisers applied. Th e data indicate that excessive P fertiliser is applied to many chickpe a crops, with only a few crops being inadequately supplied.