FIELD CROPS. 31 



COiniHKsition of the aiimuil crops was alsodctvrniiiifd :ui<l all results are herere]K)rted 

 in tables. 



A loss of humus was foun<l to have taken place in a large number of fertilized and 

 unfertilized plats, this loss l)eing esi>ecially eVident on the plats on which cotton was 

 grown continuously. The maintenance of the sui)ply of hunuis in the soil was fully 

 as good on fertilized plats with only the roots and stubble of eowpeas turned under 

 as on the unfertilized jjlats on which the whole growth of the eowpeas was turned 

 l)ack to the soil. On 13 of the plats a more or less close agreement between the 

 yields of wheat in the fourth year and the losses and gains of nitrogen, humus, 

 and humie nitrogen was observed, while in the other eases the results appeared 

 contradictory. 



With reference to the relatit)ns l)etween the (quantities of phosphoric acid and 

 potash removed by the crops and the (juantities shown to have been removed from 

 tlie soil by the present methods of analysis, the author concludes from the data that 

 none of the methods employed give absolutely reliable results for available phos- 

 phoric acid and potash, and he believes that field experiments are much less adapted 

 to the solution of the question than pot experiments, because the (conditions can be 

 better controlled in the latter. 



Culture trials on Swedish, moor soils, 1900-1902, II. vox Feii.itzex [Srensk 

 MosslnJt. TicM-r., 17 {190S), Nu. ^, ^jp- 105-1,35). — Accounts of a number of different 

 experiments conducted by the Swedish Moor Culture Association during the years 

 are given. Tlie exj^eriments include trials on moor soils with oats and barley, as to 

 time of sowing and size of seed grain; inoculation experiments with soils and pure 

 cultures of bacteria from legumes; green manuring; and tests of the value of barn- 

 yard manure with peat litter, straw, or shavings used for bedding, etc. — p. w. woll. 



Continuous culture -witliout manuring- for 75 years, W. Christiaxi {Deut. 

 Lundw. Presse, 30 {1903), Xos. 26, pp. 217, 2 IS; 27, pp. 226, 227; 28, p. 236) .—On the 

 humus alluvial soil on which these experiments were conducted good yields of 

 cereals were obtained after 75 years continuous culture. The soil, however, had 

 become "beet sick." 



Growing' and preparing agricultural crops for exhibition, B. V. Buffum and 

 A. Xelsox ( ]Vi/(»ni)Kj Std. Bui. 53, pp. 1 -') . — This bulletin gives detailed directions for 

 the growing and preparation of grains, grasses, vegetables, and fruits for exhibition 

 purposes. Suggestions for the selection of specimens and their exhibition are given, 

 and the methods of labeling them are presented. 



Cassava, S. M. Tracy {U. S. Dept. Agr., Farmers' Bui. 167, 2)p. 32, figs. 11).— The 

 varieties of cassava are described, the history of the plant briefly noted, and the 

 regiori suited to its culture shown on a map. The soil and moisture requirements 

 and the climatic conditions suitaljle for the growth of the crop are discussed, and 

 directions for the use of fertilizers, preparation of the ground, and planting, cultivat- 

 ing, harvesting, and storing the crop are given. Diseases attacking the plant and 

 preventive measures for the same are noted. The yields and profits of cassava 

 culture are estimated and the uses of the crop as a feed for cattle, hogs, and poultry, 

 and its value for the manufacture of starch are pointed out. 



Selecting' and preparing seed corn, P. G. Holdex et al. {Iowa Sta. Bui. 68, pp. 

 273-286, figs. 11). — This bulletin gives information regarding the purchasing and 

 testing of seed corn and its preparation for planting. The importance of planting a 

 uniform number of kernels per hill is dwelt upon and it is recommended that the 

 planter usetl should drop 93 to 96 times out of a hundred the number of kernels 

 desired. Planter tests showing the number of kernels dropped when they were 

 uniform and unequal in size are reported. When uniform-sized kernels were used 

 the planter in one test dropped 2 kernels 8 times and 3 kernels 92 times out of a 

 hundred. With kernels irregular in size the number of times 1, 2, and 4 kernels 



