Rotation of crops as a means of refreshing the soil has long been knovvn and applied in European agriculture, and some sugar-planters have at last appreciated the advantages to be derived from it. In Mauritius, it is now becoming the general custom, after the land has borne canes for 2 seasons, to plant it with maize (Indian corn), arrowroot, manioc (cassava), or peas, allowing a period of 3 years between the cane crops.
Fellows and tillage may be considered together, as there is very little good in allowing land to lie fallow (unoccupied by any crop) without subjecting it to thorough tillage, so as to open it up, and expose it thoroughly to the action of the air. Green-soiling is probably more beneficial than merely allowing the land to lie fallow. In Demerara, rotation is rarely practised, the same land growing canes for many successive years ; but care is taken to manure well, and to make constant interchange of plants between different estates.
Laying-cut an Estate.—The laying-out of a sugar estate is a much more complicated affair in British Guiana than elsewhere, as it mostly includes provision for drainage and irrigation. Here the plantations are mostly narrow rectangular strips of land, with a water-frontage varying from 100 to 300 Rheinland ruthe or roods (of about 124 ft.). Every estate is bounded by 4 dam.s : the front dam excludes the sea, river, or canal ; the back dam excludes the bush-water, which, in heavy weather, would inundate the cultivation. The clay thrown out in forming the adjacent canals or trenches affords the material of which the dams are formed. Along each of the remaining sides, runs a dam from front to back, usually termed " side lines " ; they serve two contiguous estates, and prevent the influx of water from the sides. The dams ansv,,er the purpose of a road round the estate ; but the produce is brought to the buildings (often situated in front) by canals. The arrangement of the navigation system is very simple. From front to hack, through the centre of the estate, runs a dam called the " middle walk," with a canal on each side, termed " central canals," wide enough to admit two punts abreast. The dam forms a path for the cattle that draw the punts. At intervals, branch canals strike off at right angles, and proceed to within a rood of the draining or side-line trenches, which are parallel and adjacent to the side dams. These branch
canals constitute the transverse boundaries of the fields, and navigation canals thus lie on three sides of every field, and admit of canes being carried by a short path to the punts. On some estates, there is only a single central navigation canal. These canals are principally supplied by the rain, but in protracted droughts, and especially when they are shallow, they are liable to run short of water : hence, whenever access can be got to creek-, lake-, or bush-water, it is brought from behind to supply the navigation system. la other instances, salt water has to be taken in from the front. The drainage of the estate is equally simple. From back to front, and imme diately adjacent to the side-line dams, run the 2 main draining-trenches, generally dug considerably deeper than the navigation canals. The small drains, again, cut at distances of 2-3 roods apart, commence within a bed of the middle-walk side of the field, and terminate in the side-line draining_ trenches, having a fall in that direction. The small drains are thus at right angles to the maiu draining-trenches. Ia the front dam, the sluices or " kokers" are placed. Sometimes there is oae on an estate, but generally two, one at the end of each draining-trench. The main draining trenches are generally connected by a trench running behind the front dam.
Drainage.—The proper drainage of a sugar estate is a most important matter. This is especially the case in localities which possess no natural means of taking off the .surplus water, as for instance, the flat lands of British Guiana. Open drains are at present the only ones in use on almost all sugar plantations. Besides being very ill adapted to the purpose, they entail great expense yearly to keep them clean. But perhaps their greatest disadvantage is the extent of land they occupy. On an estate of 500 acres, no less than 50 acres are lost in drains alone. Moreover, however well constructed, the sides are perpetually slipping in, and greatly preventing the flow of water. Other drawbacks are the inability to use the plough or tilling-machine, and the loss of fine earth which is being continually swept away during rainfall.