Agricultural Education Exhibition, Doncaster, 1912. 207 



(4) the use of inoculating material for leguminous plants, (5) 

 the effect of growing deep-rooting plants and grasses for the 

 eradication of wild onion. 



1. Heatiyig of soil. — The soil used was the light sandy loam 

 of the Woburn farm, one pot containing the natural soil and 

 another the same soil after heating it to 100*^C. Sweet peas 

 were grown in each pot, but there was no evidence, in the 

 relative growth, of any lieneficial result from the heatiug. 

 Former experiments with wheat on this same soil, however, 

 have shown benefit to accrue from the heating, and it may be, 

 therefore, that the nature of the crop constitutes an important 

 factor in the case. 



2. Influence of lime on natural and heated soils. — The 

 soil here used was black land from the Cambridgeshire fens. 

 On this a barley crop will not grow well, and, even when lime 

 is added, little benefit is seen. But it was found (and here 

 shown) that if the soil be heated to 80''C. and then lime applied, 

 there is a most marked benefit. 



3. Heating of acid soil. — The soil of plot 2b of the con- 

 tinuous barley experiments (which had been rendered acid 

 through the long use of sulphate of ammonia) was subjected to 

 heating, to see if this benefited the soil. But the result was 

 shown not to be satisfactory, the barley crop not being even as 

 good as on the acid soil without heating, and affording a great 

 contrast to the marked benefit produced by the use of lime. 

 The weed growth (mainly spurry) was, however, quite checked 

 by the heating. 



4. Inoculation of leguminous crojjs. — The crop tried was 

 beans. In one pot beans were sown in the ordinary way, and 

 in another the beans were steeped in a new American prepara- 

 tion for inoculation purposes before being planted. As the 

 plants grew, there seemed to be some slight benefit from the 

 inoculation. Subsequent weighing of the crop confirmed this, 

 there being more pods and also beans from the treated seed, 

 though the total weight was only slightly increased. There 

 was, however, considerably more straw where inoculation 

 took place. 



5. Eradication of Wild Onion. — This exhibit, perhaps 

 more than any other, attracted attention. It consisted of soil 

 from two plots on a field at Chelsing, Ware, on which wheat 

 was growing. In one case the soil had been left cultivated in 

 the ordinary way, and here wild onion was very prominent and 

 the plants growing vigorously. In the other the land had been 

 laid down four years previously with a mixtui-e of deep-rooting 

 grasses and plants (Elliot's mixture), then ploughed up and 

 wheat sown. Here there were only one or two wild onion 

 plants left and these very attenuated in growth. The soil too 



