The effect of pre-treatment of native pasture and sowing rate on establishment of Townsville lucerne of Tippera clay loam at Katherine, NT

Abstract

At Katherine, N.T., on Tippera clay loam soil, Townsville lucerne (Stylosanthes humilis H.B.K.) was sown in December 1965 at 4, 16, and 64 lb an acre of abraded pods into uncleared uncultivated perennial native pasture that had been subjected to three pre-treatments : heavy grazing in the previous wet season, late dry season burning, and early wet season burning. The amount and incidence of rainfall was particularly favourable for establishment. At counts made in December 1965, and in January and February 1966, pre-treatment did not affect Townsville lucerne density, which was proportional to sowing rate on all pre-treatments. Dry matter yields of Townsville lucerne in April 1966 were higher after early wet-season burning than after other pre-treatments. At a final seedling count at the start of the next wet season, December 1966, there was an interaction between pre-treatment and sowing rate, seedling density showing an approximate correspondence with dry matter yield of Townsville lucerne in April 1966. At the practical sowing rates of 4 and 16 lb an acre, first and second year seedling densities and first year yields were comparable with average figures for Townsville lucerne established with full land clearance and cultivation.