In many human cultures, agriculture is practiced as an extractive industry, in which the nutrition in the soil is sucked out by the repeated growing of crops, and soils are routinely degraded throughout the world.
The conversion of land to agricultural purposes alters the entire ecosystem, and the resulting impact on soil structure and fertility, quality and quantity of both surface and groundwater, and the biodiversity of both terrestrial and aquatic communities diminishes present and future productivity. Crop rotation and the application of livestock manure help to reduce soil erosion, but in some parts of the world the land is robbed of even cow dung by the need of growing populations for something to burn as fuel for cooking and staying warm.
The eroded soil has to go somewhere, of course, and its usual destinations are riverbeds and lake bottoms, where it often causes secondary problems by choking reservoirs.
Agriculture is practiced as an extractive industry and as a result:
The passage says the nutrition in the soil is sucked out by the repeated growing of crops, that is by not allowing the soil to lie fallow.
Treating agriculture as extractive means taking nutrients out faster than they are restored.
Continuous cropping without fallow periods drains the soil's fertility.
A fallow period lets the soil rest and recover its nutrients naturally.
The passage does not attribute the loss to machinery, nor does it say nutrition is replenished.
Hence the correct effect is that nutrition is sucked out by not allowing the soil to be fallow.
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