766 



XoTicEs OF Books. 



[XOY., 



grass-land, have been started to ascertain the value of modem slags and of 

 mineral phosphates. In addition, an elaborate series of pot experiments is in 

 hand to determine whether any constituent besides the phosphate is of value. 



Manures not onlv increase the crops : thev bring about other changes, and 

 these are being examined by the botanical staff of Eothamsted. The effects 

 of manures and cultivations on crop yields are by no means simple or straight- 

 forward. Every farmer knows the variations due to season and weather 

 conditions : and although weather may never be controllable, foreknowledge 

 of its probable effects on crops would be very valuable. In order to study 

 these effects, a Statistical Department has been set up to carry out an analysis 

 of the meteorological conditions at Rothamsted in conjunction with the crop 

 records since 1852. 



However skilfully artificial manures are applied, it is essential on ordinary 

 farms to add organic matter to the soil. Four ways of doing this have been 

 investigated at Eothamsted. Experiments in the production of artificial 

 farmyard manure have also been made and are being continued. Laboratory 

 work has shown that the breaking-down of the material of straw is brought 

 about by organisms. One of these organisms had eluded all previous inves- 

 tigators, but the Eothamsted workers succeeded in obtaining it in pure 

 culture. stud}-ing it freely, and determining the conditions it requires to act.^' 



Experiments at Rothamsted have shown how clover — one of the most 

 difficult crops_to grow — can be improved. In another direction, no fewer than 

 10 workers are engaged on a sm-vey of soil population — those soil organisms, 

 invisible to the naked eye, yet present in vast numbers and in extraordinary 

 variety, without which organic manure would be not only quite useless but in 

 some cases harmful. The ultimate aim of the agriculturist is to control this 

 soil population in much the same way that the animal breeder has controlled 

 and developed the original wild animals. Control, however, is not possible 

 ™hout full knowledge of what the organisms are, what they do. and how 

 they live : and it is this knowledge which the Eothamsted scientific workers 

 are endeavouring to acquire, 



Rothamsted s War Work. — The most important War work performed at 

 Rothamsted was begun in 1916. when the food situation was causing great 

 anxiety. This country was producing only one-half of our total food. Worse 

 still, the food produced included more of the luxuries than of the necessaries — 

 for instance, all the highest-quality meat but only one-fifth of the bread. 

 Farmers were therefore called upon to perform a double task : they had to 

 produce more food, and different food ; to give us three or four loaves out of 

 every five loaves required, instead of only one out of every five as hitherto ; 

 and to do this without causing too-great shortage of milk or meat. The 

 situation presented many difficult administrative, financial and technical 

 problems. How Eothamsted helped to solve the problems involving soils and 

 f ertihsers is told in this Eeport, which should be in the hands of every farmer 

 who is interested in learning what Science is attempting to do for Agriculture. 



- See this Journal Vol. XXVIIL p. 398. 



