日光温室栽培番茄引起生理障碍的NO_3-N浓度的研究

The NO 3 N Contents of Causing Physiological Barriers of Tomato in Sunlight Greenhouse

利用温室和盆栽试验，研究土壤施入不同浓度ＮＯ３Ｎ和氮肥不同施用量对番茄引起生理障碍结果表明，施入ＮＯ３Ｎ浓度在０～５０００ｍｇ／ｋｇ土处理中，番茄产量最高安全浓度为７５０ｍｇ／ｋｇ土处理，临界浓度为１２５０ｍｇ／ｋｇ土；毒害浓度为１５００ｍｇ／ｋｇ；致死浓度为３０００ｍｇ／ｋｇ土处理。随着ＮＯ３Ｎ浓度增加，番茄株高、茎粗、座果数明显降低，幅度为２５％～５０％，且品质下降。日光温室中亩施２５ｋｇ尿素，番茄产量最高，亩施１５０ｋｇ尿素比亩施尿素２５ｋｇ减产１９．００％，施入过量氮肥不仅导致了植株体内ＮＯ３Ｎ含量增高，而且影响植株对钙、镁的吸收，导致钙生理病害加重。ＮＯ３Ｎ在土壤中残留量多，是造成土壤盐渍化的主要因子。

The greenhouse and pot experiments were conducted to study the effects of NO 3 N contents and N rates on nitrogen physiological barriers of tomato, the results showed that among the eight NO 3 N contents, 0、250、750、1500、2250、3000、4000 and 5000 mg/kg soil respectively, treatment with 750 NO 3 N mg/kg soil get the maximum tomato yield. Tomato safety、critical、poison、lethal contents of NO 3 N were at 750、1250、1500、3000 mg/kg soil respectively, with contents of NO 3 N was increased, Plant hight, stem diameter of tomato decreased sharply, about 25%～50%, and the qulity of the tomato was becoming low. The rates of urea applied 25kg/mu make tomato yield reach the peak under solar greenhouse. The tomato yield at 150kg/mu urea was decreased by 19% compared with 25kg/mu urea. The more N fertilizer was applied, the more the No 3 N contents in plant was absorbed, the less uptaken of Ca and Mg, so Ca Physiological Barriers developed seriously, and soil NO 3 N tended to be accumulated evidently in subsoil under greenhouses, all of these cause the soil salimized.