ALBERT

Description: Sulphate of ammonia and nitrate of soda, applied at monthly intervals, produced increases in the carotene content of poor pasture grass amounting to 28%. Sulphate of potash, also applied monthly, produced an increase of 6·2%. A single dressing of carbonate of lime, which was sufficient to satisfy the lime requirement of the soil, produced no effect on carotene content, whilst monthly dressings of superphosphate also had no influence except in the month of June, when an increase of 14·5% was produced. All five manurial treatments significantly increased the yields of dry matter and carotene.Carotene contents were very low during the drought experienced in April and May 1938, increased significantly in June, and showed very marked and highly significant increases in the autumn months.Ash content was increased by the three non-nitrogenous manures, and protein content by nitrate of soda, sulphate of ammonia and superphosphate. Ether extract was increased by superphosphate and sulphate of ammonia, whilst nitrogen-free extract was decreased under all manurial treatments except carbonate of lime. None of the five artificial fertilizers had any effect on the mean fibre content of the grass, although various significant differences were observed on certain sampling occasions. Normal seasonal variations occurred in the percentages of ash and organic constituents.Correlations of carotene with crude protein, fibre, nitrogen-free extract and ash have been computed for each manurial treatment and several significant differences have been observed. The physiological significance of these correlations has been briefly discussed.