EFFECT OF CLIMATE ON COMPOSITION OF PASTURE PLANTS       365

Aiyer and Kayasth (4) in India conclude that, though the grasses grown on
rich black soils are richer in mineral nutrients than those grown on light soils, the
grasses of both areas are poor in phosphoric acid and lime compared with British
pastures, and that they are very deficient in nitrogen. The silica free ash of the
species investigated ranged from 2.77 to 3.69 per cent. on the black soils, and
those on light soils from 1.19 to 1.69 per cent. The corresponding range for
phosphoric acid was .18 to .21 for black soils, and .035 to .073 for the light soils.
The mean content of grasses from thirteen centres was .55 per cent. nitrogen, .187
per cent. for P₂O₅, and 3.04 per cent. for soluble ash.

The Government Chemist for the Sudan (5) states that the chemical examina-
tion of fodder grasses grown in the Sudan showed a low mineral content when
compared with European pastures. The most striking deficiencies are in nitrogen
and phosphorus, the average being only 40 per cent. and 50 per cent. respectively
of that of a good pasture. All grasses in the White Nile Province showed a marked
phosphate deficiency.

Follett-Smith (6) states that in an investigation at Waranama, British Guiana,
seven pasture species from Savannah areas were markedly deficient in silica free ash,
phosporic acid and nitrogen. The silica free ash ranged from .83 per cent. to 4.9
per cent., with an average value of 2.3 per cent., the phosphate content from .01
per cent. to 15 per cent., with an average value of .08 per cent., and a nitrogen
content ranging from .5 per cent. to 1.31 per cent., with a mean value of .73 per
cent. The samples were collected during the rainy season, and Follett-Smith
stated that the phosphate content would probably be even lower during the dry
season.

In an unpublished report to the Rowett Research Institute natural pastures from
the Samaru district (Nigeria) average .13 per cent. P₂0₅. The pasture from seven-
teen other centres in Northern Nigeria showed an average content as follows—
soluble ash 3.01 per cent., nitrogen .85 per cent., phosphoric acid .34 per cent.

Husband and Taylor (7) found that the crude protein content of normal Veldt
grass was much below the standard of average of European grass. The crude
protein content at maturity reached the extraordinarily low value of 1.73 per cent.
The natural grasses suffered from a decided mineral deficiency, especially from March
onwards.

Henrici (8) shows that even the average percentage of phosphoric acid in the
hill pastures of Great Britain is about four times higher than the average percentage
of the best grasses in the Veldt.