The influence of grasses and white clover on the soil fertility
2001
Kaerner, M. | Kaerner, E. | Geherman, V. (Estonian Agricultural Univ., Tartu (Estonia). Dept. of Grassland Science and Botany)
The experiment included the following species of grasses: timothy, meadow fescue, cocksfoot, red fescue, smooth-stalked meadow grass and white clover. These grasses were grown as pure species or components together with white clover in binary sowed mixtures. The result show that the influence of the grasses and binary mixtures swards on soil fertility in cultivated pastures was considerable only in the 0-5 cm and 5-10 cm soil layers. The N content of soil in the pure sowed grasses sward was practically invariable, but in binary mixtures sward it increased by 0.01-0.04 per cent. The content of soil humus increased in the pure sowed grasses and binary mixtures swards in the 0-5 cm soil layers by 0.02-0.13 per cent and 0.49-0.69 per cent respectively, but in the 5-10 cm soil layers by 0.01-0.07 and 0.00-0.08 per cent depending on the species of grass. The P2O5 and K2O content of soil increased in the pure sowed grasses sward in the 0-5 cm soil layers by 14.0-17.5 mg and 13-30 mg per 100 g of soil respectively. In the 5-10 cm soil layers these indices increased only 0.5-15.0 mg and 4-14 mg per 100 g of soil respectively. The P2O5 and K2O content of soil was increased in the binary mixtures swards likewise, but not so much as in the pure sowed grasses swards, in the 0-5 cm soil layers by 5.0-11,5 mg and 1-8 mg per 100 g of soil respectively. In the 5-10 cm soil layers the P2O5 content of soil increased only 1 mg, but the K2O content of soil decreased 7 mg per 100 g of soil, especially with smooth-stalked meadow grass
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