By the 1870s there was considerable expansion of the rural industries. The sheep population exceeded 5 million, cattle numbers were over 2 million and some 80 000 pigs were raised on mixed farms. Over 100 000 horses provided traction power for cereal farms which approached 1.5 million acres with 1.3 million being used for wheat.
But the pioneer agriculturists with little knowledge of their new farming environment and no tradition for a permanent farming system, ran into difficulties as soil fertility declined, threatening the very existence of cereal growing over large areas. By mid 1870 the average wheat yield had fallen to 8½ bushels per acre. The dramatic effect of the use of superphosphate on cereal yields stemming from the work of Professor Custance, and later Professor Lourie, at Roseworthy is well known; however, it took many years before farmers generally accepted the need for regular phosphatic manuring in cereal areas.”