FIELD CROPS. 563 



figures ranged from 14 to 31 per cent and decreased to 13 per cent when potash was 

 given in excess. The tigures for tobacco varied greatly with the different varieties 

 and were quite irregular. The average figures show that for each gram of potash 

 potatoes, buckwheat, and oats contained 42, 79, and 49 gm. of starch, respectively. 

 Sugar beets contained 150 gm. of sugar for each gram of potash and chicory 247 gm; 

 of carljohydrates calculated to the starch equivalent. Tobacco seed contained 25 gm. 

 and mustard seed 30 gm. of fat for each gram of potash. It is calculated from the 

 results of these experiments that 0.51 kg. of potash is required fur the production of 

 100 kg. of fresh potatoes, 4.2 kg. f.ir 100 kg. of tol)acc() leaves, 0.103 kg. for 100 kg. of 

 green mustard i)lants, and about 1 kg. for 100 kij. of dry matter in the entire oat jilant. 



Fertilizer tests on grass, barley, and swedes {Bd. Acjr. \_Lovdoit'], Rpt. Agr. 

 Education and Research, 1900-01, pp. 4S-50, 58-72). — Fertilizing pasture with high 

 and low grade basic slag gave inconclusive results, and there was no apparent differ- 

 ence in the effect of the 2 kinds of slag on the character of the herl)age. In the 

 results from fertilizer tests with barley in 1900, it was observed that the influence of 

 nitrogenous manure was most apparent and that pho.sphatic fertilizers together with 

 sulphate of annnonia also increased the yield of grain. The effect of potash was very 

 slight. In 1901 results indicated that when the yields of grain and straw and the 

 malting properties of barley are concerned a complete mixture of connnercial fertili- 

 zers is most profitable. The following is considered a suitable application : 1 cwt. 

 sulphate of ammonia, 2 cwt. superphosphate, 2 cwt. kainit. With swedes the gen- 

 eral results show that better crops were grown by mixtures of commercial fertilizers 

 than by barnyard manure. Suljihate of ammonia and nitrate of soda are much more 

 effective than either potash or phosphates in increasing the hay crop. In this con- 

 nection the dangers of heavy dressings of nitrogenous fertilizers are discussed and 

 cas^s are pointed out where clover was killed by the use of sulphate of ammonia or 

 of nitrate of soda. 



Experiments with, phosphatic fertilizers on meadows and rye, Remy {Deut. 

 Landir. I'trs.'^e, 29 {1902), Nos. 90, p. 729; 93, p[>. 753, 7.5.^). — The results of coopera- 

 tive experiments with superphosphate, Thomas slag, and Algerian i)hosphate on 

 meadows and rye are ta])ulated in detail and discussed. The results showed that in 

 general phosphatic acid in finely ground Algerian phosphate is equal in \'alue to 

 phosphoric acid in the form of Thomas slag. 



Alfalfa on Illinois soil, C. G. Hopkins {Illinois Sta. Bui. 76, pp. 311-349, figs. 

 9). — Results of pot and field experiments are reported. The purj^ose of the experi- 

 ments was to determine the value of furnishing the soil with different elements of 

 plant food in 'alfalfa culture and to study the effect of inoculating the soil with bac- 

 teria whi(;h enable the growing alfalfa plant to use the free nitrogen of the air. 



The observations showed that the bacteria which enable alfalfa to obtain nitrogen 

 from the air are usually absent in Illinois soils, and that the crop for this reason ia 

 entirely dependent upon the soil for its nitrogen. Without the proper soil bacteria 

 an exceedingly rich soil and liberal apiilications of nitrogenous fertilizers are required 

 to produce good crops of alfalfa. Even the rich black prairie soil of Illinois lacked 

 sufficient available nitrogen for maximum crops, and applications of available nitro- 

 gen produced yields of hay from 2 to 4 times as large as crops entirely dependent 

 upon the natural supjjly of the soil. An experiment further showed that inoculated 

 soil produced crops just as large as soil heavily fertilized with commercial nitrogen. 

 On most soils, excejjt limestone soils, the application of air-slaked lime as well as 

 inoculation with bacteria has proved beneficial. 



In studying the effect of the different plant food elements in the different experi- 

 ments it was found that a complete fertilizer with lime gave better results than appli- 

 cations lacking in one element or lime. The maximum losses when either nitrogen, 

 phosphoric acid, or potash were lacking were 3,200, 1,440, and 480 lbs. of hay per 

 acre, respectively. The author considers these figures as fairly representative of the 



