ilf«r. 2, 1908. J jigricultural Gazette of N.S.W. 205 



a total of 136 lb. nitrogen per acre. Assuming that conditions are favourable 

 for nitrification, this will be equivalent to a dressing of nearly 7 cwt. sulphate 

 ■of ammonia per acre, or over 11 cwt. dried blood — an enormous dressing. 



The soil in which this crop was grown was a light loam with about 25 

 per cent. clay. The clay is of a tenacious character, and has a tendency to 

 cake hard on drying. The soil is low in humus, containing only about 4 per 

 cent, of this ingredient. It is fairly rich in potash and satisfactorily supplied 

 with lime, but rather low in nitrogen and phosphates. It is, consequently, 

 just the type of soil in which green-manuring should be effective, as the effect 

 of ploughing under the crop will be to break it up and render it more friable, 

 and to supply the deficiences in humus and nitrogen. Its efficacy is, of course, 

 dependent upon conditions as to rainfall being favourable to its decomposition 

 in the soil. The climate of Wagga is not very favourable to the growth of 

 these crops. 



At Bathurst, and at the Hawkesbury College, where conditions are more 

 favourable, the benefits of green-manuring are even more striking. Mr. 

 Allen obtained similar samples of tops and roots, representing the produce 

 of one square yard from crops grown at these places, and they gave the 

 following figures : — 



At Bathurst, the tops weighed 17 lb. and the roots 21b. 5 oz. per square 

 vard, or 36 tons 14 cwt. tops and 5 tons of roots per acre, giving a total 

 of dry matter to be ploughed under of 4 tons 15 cwt. from the tops and 

 16 cwt. from the roots. Assuming the same nitrogen content in tops and 

 roots as was found in the Wagga plants, this will give when ploughed under 

 411 lb. nitrogen per acre from the tops and 22 lb. nitrogen from the roots. 



At Hawkesbury, the produce was 21 tons 12 cwt. tops and 4 tons 14 cwt. 

 roots per acre. When ploughed under, this would yield 2 tons 16 cwt. dry 

 matter from the tops and 16 cwt. dry matter from the roots. With "5 per 

 cent, nitrogen in the tops and "2 per cent, in the roots, the soil will be 

 enriched in nitrogen by 242 lb. per acre from the tops and 22 lb. from the 

 roots. 



