Nitrate in Plants: Its Relation to Fertilizer Injury, Changes during Silage Making, and Indirect Toxicity to Animals 1

Synopsis Nitrate accumulation occurred in stalks or stems of corn, sorghum, and soybean plants. Legumes in the rotation or applications of manure or nitrogen fertilizer increased the nitrate content of the plants. The amount of nitrate in plants depended upon the stage of maturity, the degree of drouth injury, and the availability of nitrogen in the soil. Nitrate content was reduced but not destroyed by ensiling corn plants.

supporting

confidence: 53%

mentioning

confidence: 71%

Nitrate Accumulation in Some Iowa Crop Plants¹

Hanway¹,

Englehorn²

1958

“…Nitrate poisoning has been :ommon among animals grazing on nitrate-rich forage or feeding on nitrate-rich fodder, hay, or silage (4,5,6,18,21 ). Because certain plant parts eaten as vegetables may accumulate N0 3 to high levels (1, 2, 7,10,11,19,20), they represent potential sources of toxicity to human beings ( 17). Although no authenticated cases are known for nitrate poisoning of human adults who have eaten plants high in N0 3 , there have been reports of poisoning of very young babies who have been fed spinach with a high N0 3 content (10).…”

mentioning

confidence: 99%

Nitrate Accumulation in Vegetables. I. Spinach Grown in Upland Soils¹

Barker¹,

Peck²,

MacDonald

1971

The nitrate concentrations in spinach (Spinacia oleracea L.) blades and petioles were determined for different sources and times of application of N fertilizers to a Honeoye fine sandy loam and a Lima silt loam to determine the effect of N fertilization on the concentration of nitrates in the plant parts used for consumption for food. Nitrate concentrations were determined potentiometrically, using a nitrate‐selective ion electrode, on plant samples taken at time intervals after N fertilization and at harvest stage for processing. Nitrogen fertilization substantially increased the NO3 concentrations of spinach grown in upland soils. The following observations were significant: (a) More NO3 accumulated in leaves of plants broadcast with N fertilizers before planting than if an equivalent amount of N fertilizer was supplied by sidedressing one week before harvest. (b) The N carrier was a significant factor in governing NO3 accumulation when it was applied as sidedressing.

“…N ITRATE accumulation in plants has been observed for many years, but interest in nitrate accumulation has intensified since the mid-1950's with increased use of nitrogen fertilizers (2,7,14,18,19,20). The conditions causing nitrate accumulation in plants and the effects of nitrate in plants on animal physiology have been studied in detail (4,10,16,20,21). A comprehensive coverage of the subject of nitrates in relation to plants and animals can be found in the review by Wright and Davison (22).…”

mentioning

confidence: 99%

“…The overshadowing objective of many of the studies made on nitrate has been to elucidate the effect of nitrate and nitrite on animal production and health. Animal studies have invariably been made on laboratory and domestic animals with relatively few studies on the effect of nitrate on humans or even on the occurrence of nitrate in food intended for human consumption (13, 20,21).…”

mentioning

confidence: 99%

Soil Fertilization and Nitrate Accumulation in Vegetables¹

Brown¹,

Smith²

1966

Five different rates of nitrogen were applied to plots upon which were grown several different varieties of vegetables. Nitrogen fertilization caused significant increases in nitrate content in red radishes, kale, mustard, and turnip roots and tops. The maximum accumulation of nitrates appeared to vary with species, but differences in harvest dates between species precluded valid statistical tests of the differential accumulations. No significant differences in nitrate accumulation were found between varieties of the same species. Early maturing vegetables tended to accumulate more nitrate than late maturing varieties at a given rate of fertilization. Differences in nitrate content were observed at different sampling dates. The absence of phosphorus, potassium, or lime, or the presence of trace elements in the fertilizer treatment had no significant influence on nitrate accumulation.