xxxviii. Timehri. 



change this vievv. He would there find that with the exception of a very 

 thin layer of .lark-coloured earth covering the land the soil is light grey 

 to almost white in hue. 



That light colour indicates a former, if not a present, abundance of 

 plant-debris. During the rapid decomposition and oxidation of such 

 debris, organic acids, including carbonic acid, are produced and the waters 

 containing them leach-out from the soil the dark-coloured organic iron 

 compounds which if present would tinge the earth dark grey to almost 

 black. It is the superabundance, either in the present or in the past, of 

 decomposing vegetable debris which results both on sugar-cane lands and 

 on the river alluvial soils in the production of light-coloured to almost 

 white earths. 



The system formerly in force here on sugar estates, but which has 

 been widely abandoned since 1897, of burying the trash, cane-tops, etc., 

 between the rows of canes tended directly towards the conservation of 

 plant-residua in the soil, but unfortunately financial difficulties, unsatis- 

 factory labour and other conditions have compelled the planters to burn 

 their canes prior to reaping them. This system naturally interferes with 

 the accumulation in the soil of plant-residua.* 



Two methods of assisting in the amelioration of the soil by addition 

 of plant residua have recently been advocated but not by agriculturists resi- 

 dent in the colony. In the first it was proposed to add to the soil forest 

 leaf-mould. Now to add plant-debris to the soil to| the extent of one-half 

 of one per cent, of the upper surface layer of the soil would require the 

 addition of 15,000 lbs. of such debris per acre and that would entail the 

 application of at least 37,000 lbs., probably of 50,000 and possibly of 

 far more of forest Ieafmould. Some time ago for another purpose I 

 ascertained that under heavy forest at Issorora, North West District, 

 the wet fallen leaves over an acre of land weighed only tij tons. It would 

 take all such fallen leaves from three acres of forest land to dress the soil 

 of one acre of caneland with the equivalent of a relatively light dress- 

 ing of organic debris such as is furnished by farm-yard manure. 



Application of pegass dug from the land at the back of the planta- 

 tions to the canefield has been also suggested. As a tentative proposal at 

 first sight it appears a very practical one, but when it is remembered that 

 the nitrogenous and other agents of soil fertility; present in pegass are in a 

 condition of extreme insolubility and hence non-availability and that pegass 



* Under our former system of agriculture probably from 2.) to SO per cent of the nitrogen 

 in the cane, fjii per cent, of the potash, and (6 per cent, of the phosphoric acid were returned 

 to the soil by the tops gad dry Leaves. There was, therefore, little chance of the exhaustion 

 of the soil by continued cropping, except of the immediately available nitrogen, which was 

 then easily and cheaply supplied in the form either of sulphate of ammonia or of nitrate 

 of soda. A very large proportion of the great quantity of vegetable matter con- 

 served to the soil under the former system is now, undor the system of burning the 

 canos, entirely lost ; almost all of the combined nitrogen is lost whilst the potash and phos- 

 phates of the vegetable matters are rendered more or less insoluble, inert, and u less for 

 the production of later crops. 



