Ключевые слова: agriculture, background, balls, benefits, black, carbamide, chemical, chemistry, circle, closeup, ecology, environmental, factory, farm, farmer, fertilize, field, flake, garden, glass, grain, granule, growth, healthy, heap, humus, industrial, industry, laboratory, material, natural, nitrate, nitrogen, nourishing, nutrient, organic, pellets, ph, phosphate, phosphorus, pile, plant, potassium, rural, seed, small, soil, sow, urea, white,