534 EXPERIMENT STATION RECORD. 



per hectare. The use of nitrate of potash proved most profitable 

 when combined with phosphoric acid, barnyard niaiiurt\ or oreen 

 manures. 



In 1897 and 1898 barnj^ard manure from deep stalls produced yields 

 of 321 and 165 kg. per hectare, respectivel}', more than barnyard manure 

 obtained from common stalls. Plowing under catch crops in the fall, 

 rather than the spring, has given best results for potatoes. 



Some experiments were made with field-crop seeds. A portion of 

 the seeds grown at the station were sent out to farmers for comparison 

 with the seeds usually employed by them. In general, the station- 

 grown seeds gave considerably better results. 



In investigations with green manures it has been found that these 

 manures possess the same high value for better soils as for lighter soils. 

 Green manuring was found profital)le with every crop, but proved 

 especially valuable for sugar and fodder beets, potatoes, and carrots. 



The most suitable plants for green manuring consisted of a mixture 

 of 5() per cent of horse beans, 25 per cent of vetch, and 25 per cent of 

 peas. Plowing the green manure under in the fall gave best results, 

 except with crimson clover or a mixture of hairy vetch and rye, which, 

 when sown late in the season, made its greatest development in the 

 spring. Phosphatic and potash fertilizers were profitably used with 

 green manures, but nitrogenous fertilizers were hardly necessary. 



The experiments to determine the economic use of barnyard manure 

 involved the utilization on difl'erent crops of barnyard manure from 

 deep and from common stalls, of sheltered and unsheltered manure, 

 barnyard manure sprinkled with a weak solution (li to 2 per cent) of 

 sulphuric acid, and manure preserved with a mixture of marl and 

 peat and with ''sulfarin," a fertilizer-preserving mixture composed 

 of sulphate of magnesia containing 15 to" 18 per cent of free sulphuric 

 acid. The best results with sugar beets and potatoes have been obtained 

 with barnyard manure from deep stalls preserved under shelter. When 

 barnyard manures were used, the further addition of commercial ni- 

 trogenous manures was not profitable. Additions of phosphoric acid, 

 on the other hand, gave largely increased returns. Treating barnyard 

 manures with a li to 2 per cent solution of sulphuric acid preserved 

 the ammonia in the manures and pi'ofitably increased the yields. The 

 use of "sulfarin '" in preserving barnyard manure rendered the manure 

 much more effective, but its high cost made the use of sulphuric acid 

 for this purpose more economical. Treating stall maiuii'e with 5 per 

 cent of its weight of marl incrcnised the potato crop 211 kg. per hec- 

 tare Wh(Mi 2 per cent of peat moss was added, the yield was increased 

 IHo kg. pel- hectare. These results wer(^ not quite as good as those 

 o}>taine(l with the barnyard maimre treated with sulphuric acid. The 

 method used for incorporating siil])imri(' acid with the maiuires has 

 been noted elsewhere {K. S. R., 11. p. 725). 



