Final answer:
Grass tetany in cattle, characterized by low magnesium levels, is not typically prevented with phosphorus supplements. Phosphorus needs are usually met through the diet, while magnesium is more critical in preventing this condition. Farmers add nitrogen and phosphorus to crops as essential nutrients to promote plant growth.
Step-by-step explanation:
Grass tetany is a condition that affects cattle and is characterized by low magnesium levels in the blood, which can lead to neuromuscular problems. This condition can indeed be aggravated by diet imbalances, including deficiencies in magnesium, rather than phosphorus. Although phosphorus is important for cattle, as it is involved in numerous bodily functions and is found in all foods, a deficiency in phosphorus itself is not commonly known to occur. In fact, dairy products, cereals, egg yolk, meat, beans, and nuts are rich sources of phosphorus, providing an average daily intake of 800-1000 mg. Therefore, to prevent grass tetany, the focus should be on providing adequate magnesium in the diet, not phosphorus. Farmers use fertilizers with elements like nitrogen and phosphorus because these are essential nutrients for plant growth. As stated, organic agriculture prohibits the use of synthetic fertilizers, encouraging natural sources to supply these essential nutrients.