Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

Effects of management on soil fertility under pasture. 1. Influence of experimental grazing and fertilizer systems on growth, composition and nutrient status of the pasture

JR Simpson, SM Bromfield and GT McKinney

Australian Journal of Experimental Agriculture and Animal Husbandry 14(69) 470 - 478
Published: 1974

Abstract

Pasture plots containing phalaris, subterranean clover and annual grass species were fertilized annually at suboptimal (P1), adequate (P2) or a 'luxury' rate (P3) of superphosphate. A fourth treatment combined rate P3 with fertilizer nitrogen (P3N). Each pasture was grazed during five years at a high (H) or a low (L) grazing pressure in such a way that there was little feed left on the H plots and a large amount on the L plots at the end of summer. In this way eight pasture situations were created which differed in botanical composition, nutrient availability, herbage production and the amount of nutrients returned as animal excreta. The plots were used to investigate the effects of fertilizer input and grazing pressure on the growth and nutrition of the different pasture components. Protected microplots during the fourth and fifth years showed that the P1 plots remained responsive to phosphate. The yields of annual grasses on the microplots were increased by H treatment but the proportion of phalaris to annual grasses was reduced, particularly at P1. Clover yields and total pasture yields were affected by previous grazing pressure only in the drier fourth year. At high levels of superphosphate and grazing (P3H), the greater grass-clover ratio and higher grass nitrogen uptake indicated greater nitrogen availability in this treatment.

https://doi.org/10.1071/EA9740470

© CSIRO 1974

Committee on Publication Ethics


Export Citation Get Permission

View Dimensions