FERTILIZERS. 



569 



The fertilizer is, in general, to be eonsidered iirimarily a ixftanh fertilizer, and its 

 potash is of about the same value as that of sulphate or kainit. The cost at which 

 it can be manufactured will determine the extent to which it can be used economi- 

 cally. — V. \y. woLL. 



Report of cooperative fertilizer experiments in Sweden for 1902, P. 

 BoLiN (A". Landt. Akad. Handl. och TidskT.,1903, App.,pp. 183, charts 2). — The experi- 

 ments were conducted in different parts of Sweden by the author under the auspices 

 of county agricultural societies. Two hundred and forty-six experiments, including 

 6,497 trial plats, were arranged for in all, in 16 different counties. Of these experi- 

 ments 174 were with spring grains, 47 with root crops, and 25 with pasture. The 

 following fertilizers were applied : Nitrate of soda, poudrette, superphosphate, 

 Yiborgh phosphate, Thomas phosphate, steamed bone meal, 37 per cent potash salt, 

 and kainit. 



In the discussions of the results obtained, the author calls attention to the fact that 

 an abundant fertilization with nitrogenous fertilizers may in a season of much precip- 

 itation, like that of 1902, have a deleterious influence on the yield of crops by devel- 

 oping the vegetative growth of the plants at the expense of seed formation and 

 ripening. An abundant nitrogenous fertilization retards the ripening of the grain, 

 and in seasons when the spring work has been delayed and there is therefore danger 

 of late ripening, a relatively smaller use of nitrate is to be recommended than in the 

 case of early sowing, and late-ripening varieties can stand less nitrogen fertilization 

 than earlier varieties. On the whole, a smaller effect from nitrogenous fertilizers was 

 noted on soils rich in humus than on those low in humus, but even in the case of the 

 former the increased yields obtained were sufficient to jiay for the fertilizers used 

 with small grains, 100 to 200 kg. per hectare (90 to 180 lbs. per acre) proving an 

 economical fertilization, whether the nitrate was applied alone or in conjunction with 

 other mineral fertilizers. 



The results obtained in the experiments with meadows indicate that nitrate of soda 

 and other nitrogenous fertilizers give best returns on land where the true grasses 

 predominate, or in general on old meadows, while phosphates and potash fertilizers 

 are to be preferred where there is considerable clover mixed with the grasses. 



An application of 200 kg. superphosphate jjer hectare (180 lbs. per acre), or a cor- 

 responding quantity of other phosphates, proved sufficient in case of spring grains, 

 when not more than 100 to 200 kg. of nitrate of soda was applied, or when the soil 

 itself was not especially rich in nitrogen from a large humus content. 



The average relative weights of 1,000 kernels of oats and of barley from plats that 

 received different fertilization are shown below, that of grain harvested on unferti- 

 lized plats being placed at 40 gm. : 



Influence of fertilizers on weight of kernels. 



Oats: 



Clay soils 



Loam soils 



Sandy soils 



Sandy loam soils 



Average .. 



Barley: 



Clay soils 



Loam soils 



Sandy loam soils 



Average 



Number 



of 



trials. 



Weight of 1,000 kernels. 



Two appli 

 cations ni 

 trogen + 



One appli- 

 cation ni- 

 trogen -f- 



phosphoric phosphoric 



acid -1- I acid -h 



potash. potash. 



Phosphoric 

 acid -f- 

 potash. 



Grams. 

 41.39 

 40. 55 

 42. 54 

 40.51 



Grams. 

 41.00 

 42.56 

 43.01 

 40.03 



41. 25 



41.65 



Grams. 

 41. 33 

 41.51 

 42. 41 

 40. 96 



41.55 



Nitrogen -t- 

 potash. 



Grains. 

 41.39 

 41.03 

 42. 62 

 40. 80 



41.46 



43.65 

 43.97 

 43. 73 



43.11 

 43.36 

 43.17 



41.35 

 41.98 

 42. 65 



41.99 

 41.64 

 43.06 



Nitrogen + 



phosphoric 



acid. 



Uram.s. 

 40. 35 

 40. 39 

 40. 96 

 38.93 



40.16 



41.52 

 41.28 

 42. 19 



