 Under the climatic conditions that exist, with the hot dry summers and the low rainfall in winter, the weathering action of air and water, the beneficial action of bacteria and the formation of humus in the soil, occur to considerable depths. Roots ordinarily...  Rural California - Stran 36avtor: Edward James Wickson - 1923 - 399 straniCelotni ogled - O knjigi
 | 1913 - 320 strani
...laid down a little at a time, year after year, they have been acted upon by the weathering agents, breaking up the particles and making the plant food...exist, with the hot dry summers and the low rainfall coming in winter, the weathering action of air and water, the beneficial action of bacteria and the... | |
 | 1919 - 956 strani
...accumulation of sediments in the valleys is often hundreds or even thousands of feet deep (fig. 3). Soils formed in this way may be quite uniform to great...of humus in the soil, occur to considerable depths. Roots ordinarily penetrate to depths of six to eight feet below the surface. In studying the soil,... | |
 | 1915 - 774 strani
...laid down a little at a time, year after year, they have been acted upon by the weathering agents, breaking up the particles and making the plant food...exist, with the hot dry summers and the low rainfall coming in winter, the weathering action of air and water, the beneficial action of bacteria and the... | |
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