FIELD CROPS. 541 



nitrate of soda amounted to 4.2 tons per acre. When potash and phosphate were 

 applied with sulphate of ammonia, the gains were greater than with the sulphate 

 alone, but the additional increase was insufficient to pay for the potash and 

 phosphate applietl. Similar results were secured when ix>tash and phosphate 

 were applied with nitrate of soda, so that the results support the view that sul- 

 phate of ammonia or nitrate of soda applied alone is the more profitable prac- 

 tice. The results from the use of 40 and GO lbs. of nitrogen per acre appeared 

 iuconclusive. Dried blood increased the yield by 3.2 tons i)er acre, but it was 

 not remunerative. The highest yield of cane, 20 tons per acre, was secured in 

 an experiment in which nitrogen and potash were applied without phosphate, 

 but as other experiments show that potash has little influence, the gain is attrib- 

 uteil chiefly to the nitrogen. The use of 2 cwt. of guano manure proved profit- 

 able, while 4 cwt. did not pay for itself In the increased yield. 



As in previous years, it is again indicated that under average conditions of 

 soil and rainfall, the use of either sulphate of ammonia or nitrate of soda for 

 rattoon canes is most likely to be profitable. Under conditions promising mod- 

 erate growth the use of about 2 cwt. of sulphate of ammonia or 2i cwt. of nitrate 

 of soda per acre is considered sufficient, but when there is a prospect of consid- 

 erable growth, quantities increased to 3 cwt. of sulphate of ammonia and 3i cwt. 

 of nitrate of soda are recommended. 



Manurial experiments with, sugar cane in the Leeward Islands, 1907—8, 

 F. Watts et al. (Imi). Dept. Agr. West Indies Pamphlet 57, 1909, pp. 2S, dgms. 

 2 ) . — This publication contains a brief summary of the results noted above. 



Experiments with sugar cane, Brcemer (Bui. Econ. Indo-Chine, n. sen, 11 

 (190S), Xo. 71, pp. 235-239). — Distance and fertilizer experiments are reported. 



Planting sugar cane in rows 1 meter apart and 60 cm. (about 2 ft.) apart in 

 the row gave better results than the native method of planting or placing the 

 cane at greater distances. Wide planting favored the production of a larger 

 number and a greater weight of stems per hill than did narrow planting. 



In the fertilizer test the plat producing the best yield. 26,600 kg. of cane on 

 0..5 hectare (about 23.7 tons per acre), had received 500 kg. of soy bean cake, 

 and 16.000 kg. of green manure per hectare. The green manuring consisted in 

 plowing under DolicJios alhiis. 



The action of soluble fertilizers on cane soils, C. F. Eckart {Hawaiian 

 Hufjar Planters' Sta., Div. Agr. and Vliem. Bui. 29, pp. 88). — The effect of differ- 

 ent fertilizer mixtures was studied at 4 substations. The mixtures applied fur- 

 nished nitrogen, potash, and phosphoric acid at the rate of either 60 or 90 lbs. 

 per acre. The interpretation of results is discussed and the data which form 

 the basis for calculating the results presented in the bulletin are given in tables, 

 together with rainfall and temperature records. 



It is stated that in the average Hawaiian soil 7 per cent of the potash, 0.55 

 per cent of the phosphoric acid, and 24.4 per cent of the lime is soluble in a 1 

 per cent solution of aspartic acid. In the soil at Substation A, 13.3 per cent 

 of the potash, 1.1 per cent of the phosphoric acid, and 15.6 per cent of the lime 

 was soluble in a solution of aspartic acid, and the soil contained about one-half 

 as much nitrogen as the average soil of the islands. Judging from the yield of 

 plant and rattoon canes the essential elements apparently ranked in importance 

 in the following order: Nitrogen, potash, phosphoric acid. The most suitable 

 application used on this soil was the one containing 90 lbs. of nitrogen, 60 lbs. 

 of potash, and 60 lbs. of phosphoric acid per acre. The average gain iu available 

 sugar from fertilizing the plant cane was approximately 46 per cent, and from 

 fertilizing the rattoons 93 per cent. The approximate average gain from fer- 

 tilizing both crops was 67 per cent. 



