Crop responses to lime in long-term pasture-crop rotations in a high rainfall area in south-eastern Australia

A long-term trial, known as 'managing acid soils through efficient rotation s' (MASTER), commenced in 1992 to develop and demonstrate a cropping system that is economically viable on the highly acid soils of the traditional pe rmanent pasture region in south-eastern Australia, so that their fertility is sustained or improved. There were 2 permanent pasture systems and 2 past ure-crop rotations, each with and without lime. This paper reports the effe ct of lime on crop production over the first cycle (6 years). On annual pas ture-crop rotations, lime significantly increased the dry matter production at anthesis and grain yields of wheat (cv. Dollarbird) compared with the u nlimed treatments. Averaged across years from 1992 to 1997 (excluding the s evere drought year 1994), wheat crops produced 1.6 t/ha more grain on the l imed treatments than on the unlimed treatments (3.6 v. 2.0 t/ha). On perenn ial pasture-crop rotations, the lime effects varied with crops grown at eac h phase and year. For example, despite being tolerant of acidity, oats (cv. Yarran) responded to lime in 1996. Likewise, triticale (cv. Abacus) respon ded to lime in 1997. Wheat (cv. Dollarbird) that is moderately tolerant to acidity responded to lime in phase 6 from 1992 to 1997 excluding 1994 (3.5 v. 1.7 t/ha). Acid-tolerant wheat varieties, triticale, and narrow-leaf lup ins are considered the most viable crops for the soil and climatic conditio ns encountered in this high rainfall (500-800 mm per annum) area of south-e astern Australia.