NOTES AND ABSTRACTS. 



671 



— Valuable results of experiments are here given. Several fields were 

 used, and each field cut up into plots ; for instance, in the field set apart 

 for experiments with nitrogen, three plots had no nitrogen of any sort, 

 while others had respectively barnyard manure, nitrate of soda, sulphate 

 of ammonia, and dried blood, the crops sown being Oats, Rye, Soy 

 Beans, Clover, and Potatos. From certain experiments, nitrate of soda 

 showed the best results, equal to 100 per cent., and dried blood the 

 poorest, equal to 87*7 per cent., but even this was far in front of the plots 

 without any nitrogen, which were only equal to 71*0 per cent. Many 

 tables are given, with the exact results of the experiments, and must 

 amply repay consideration. 



Legumes as nitrogen gatherers, and high-grade sulphate of potash, are 

 treated of at length, and also elaborate experiments in soil tests. All the 

 results go to show the immense benefit to be derived from manures, and 

 the reader soon discovers the best manure or combination of manures for 

 any particular crop. — V. J. M. 



Manurial Experiments and their Value. By U. Baumann (Nat. 

 Zeit. Land-Forst. i. pp. 33-41, 110-119, 473-478 ; 1903).— The first part 

 of a critical review on the possibilities of being misled by manurial 

 experiments. The author, an experienced member of the Bavarian 

 Government Agricultural Department, puts on record some startling facts, 

 which cannot well be condensed into an abstract. The methods of 

 manurial experiments may be classed : (1) Pot or box experiments ; (2) 

 Field-plots ; (3) the so-called statistical or summary method. 



(1) Pot-experiments. — These include the use of flower-pots and zinc or 

 wood boxes with or without bottoms. The boxes are either sunk in the 

 earth or not. Advantages : small space occupied ; the ease with which 

 uniform soil may be used, and manurial constituents added in exact 

 quantities ; a uniform water-supply, temperature, and other conditions are 

 ensured. Objections : (a) While the open land subjected to alternations of 

 heat and cold, wet and dry, is favourably situated for the circulation of gases 

 (e.g. oxygen and carbonic acid), no pot or box (even without a bottom) allows 

 free circulation. Thus, some pot experiments, in direct opposition to general 

 experience, show that farmyard manure is injurious, and bone-meals and 

 many phosphates are useless manures, (b) The small size of the box gives 

 a false return as to the crop ; the difference between two experiments can 

 never be great, and an insect damaging a few plants may utterly spoil a 

 result ; in favourable cases pot-crops may far exceed in weight anything 

 ever approached in field experience. The general result is that pot 

 manurial experiments are absolutely worthless as guides to what will 

 happen in the field. 



(2) Field-plots. — These are carried out on plots of ordinary field 

 land. The method is free from the objections to pot-cultures. It has 

 been proved that small plots (say one fortieth of an acre) give much the 

 same results as plots of an acre each. Two conditions must, however, be 

 fulfilled. Firstly, parallel plots should be used, at least three for each 

 manure under experiment. Secondly, the soil must be as nearly as 

 possible uniform in physical and chemical properties in all the plots. 

 This last is determined by taking numerous borings, and by a careful 



