Notes on the Society's Work in 1897-1918. xxxv. 



complete failure followed. Hence only vigorously growing beans of vari- 

 ous strains could be used ; and with them, whether Bengal beans, Woolly 

 pyrol or velvet beans were used, the results were the same. The costs of 

 cultivation and application were too high in comparison with the then price 

 of sulphate of ammonia for their practical utilisation. 



Owing to the great appreciation of sulphate of ammonia this may not 

 now be the case. Trials on the large scale should be resumed. Probably 

 the solution of this problem will be found in mechanical tillage. The 

 system to be followed should be to grow the kind of beans which are found 

 to give the heaviest returns of foliage, to cut down the mass of foliage, 

 to leave it on the land for a short 4 .ime to wilt, and when it has wilted 

 sufficiently to be easily handled, to plough or fork it in. 



Now there is a very common error with regard to leguminous cover- 

 crops. It is assumed that they are always successful in increasing the 

 nitrogen in the soil. To obtain good results you must bury, or 

 otherwise apply to the soil the whole of the produce. If you gather the 

 seed and use it for food or other purposes you take from the produce the 

 greater part of its accumulated nitrogen. Still by burying all the 

 residues after reaping the seed a certain but small proportion of the 

 nitrogen accumulated by the pulses is left in the soil. But if the whole of 

 the produce other than the seeds is removed from the field and not 

 returned to its soil, leguminous crops are practically as exhausting to the 

 soil as sugar-cane can be. 



Again the successful cultivation of leguminous crops requires larger 

 supplies of available phosphates and potash in the soil than do that of 

 the sugar-cane and similar crops. Hence it may be necessary and it 

 always will be advisable, to apply to lands which are to be planted with 

 legumes either superphosphate of lime or slag phosphate. Most of our 

 coastland soils are very plentifully supplied with potash. 



Any planter or farmer who commences the cultivation of legumes for 

 cover-crops must be prepared to meet with disappointments. Not un- 

 frequently for reasons which are not obvious the legumes will refuse to 

 grow. We have had an instance of this in our experimental work when 

 we planted legumes time after time on certain soils with the result that 

 the young plants either wilted and died when quite small or if they 

 survived for a time could not hold their own against ordinary weeds. 

 We left the land for some months in a condition for which we were 

 severely criticised by self-constituted agricultural experts ; we cut down 

 and buried the very luxuriant crops of weeds we obtained and on replant- 

 ing the land with beans we finally obtained very heavy crops of the 

 pulses. 



The high proportion of legumes which occur among the weeds in 

 this colony is very remarkable. Here I have to include the non-utilised 



