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Abstract

Weeds infest agricultural crops, fruit and berry plantations and so on. There are known several thousand species of weeds.
Weeds choke the crop plants from the soil by absorbing large amount of water and nutrients, releasing from roots harmful substances into the soil , depriving them light, and etc.; This all reduces the yield , and in some cases leads to death of seeds.
Voluble weeds (field bindweed, black bindweed) cause lodging of crops, complicating harvegting and leads to large crop losses.
Tall- stalked and succulent weeds (types of sow-thistle, thistle, mari and other) drive in working parts or cleaning machines, reducing their productivity. Hanest includes succulent crop of the weeds, which significantly increases the moisture content of grains and seeds, causing them to self-warming, reducing quality. In hayfields and pasture weeds, displacing valuable forage grasses, reduce their harvest and nutritional value, poisonous weeds cause poisoning of animals. Primary breeding centers of many pests and crop diseases often occur on weeds.The article presents contamination and seed stock of soil of agricultural fields for 2014 in Karasai district of Almaty region.