Effect Of Nitrification Inhibitor And Combination On Vegetable Nitrate Accumulation

Vegetables are indispensible food in our daily life, and also are one of the important exported agricultural products.Nitrate in vegetables is one of three big pollutants, and the exceeding content of nitrate has become one of influencing the important factors of vegetable quality. How to reduce the content of nitrate in vegetables,and satisfy people's safety in eating vegetables and improve the ability to export vegetables, has become the hot point of research in the agricultural environmental protection industry etc.Through experimental research and indoor cultivation, the pot experiment has studied the combination of different nitrification inhibitors and accumulation of nitrate in vegetables, aiming to provide some references in reducing the content of nitrate in vegetables. Main results are as follows:(1)The spinach of single plant weight and height increased through different thiourea dosages.The content of spinach chloroplasts pigment content increased with the amount of it. And it could significantly decrease the spinach nitrate content. The reducing effects which reached extremely significant level when thiourea's dosage was 7%, increased with the amount of it.Thiourea effecting on the inhibiting effect of Soil NO3--N accumulation inhibition, increased with the amount of it. When its dosage was 7%, it reached extremely significant level.(2)The spinach of single plant weight and height had a certain growing effect, when adding different level (0-9%) 2-mercaptobenzothiazole to it, and they appeared a growing trend with the amount of 2-mercaptobenzothiazole.Spinach nitrate content and soil nitrate nitrogen concentration both generally decreased, with the increasing of 2-mercaptobenzothiazole, but only 9% of its dosage reached significant level.(3)Spinach of single plant weight and height improved significantly, when adding different nitrification inhibitors (10% dicyandiamide and 5% thiourea and 9% 2-mercaptobenzothiazole) to it. Among of them,growing effect was the best adding 9% 2-mercaptobenzothiazole. Content of nitrate in spinach and its corresponding soil NO3--N concentration had significantly reduced.Among of them,10% dicyandiamide inhibition effect was the best, and 9% 2-mercaptobenzothiazole ranked second,and 5% thiourea ranked third.(4) Adapting three different kinds of nitrification inhibitors combination on the yield and quality of vegetables, the results indicated that content of nitrate qingjiang white appeared similar fluctuation curves,as urea fertilizer combined application with three different nitrification inhibitors combinations,and nitrate content of the food generally reduced.Combined application of different nitrification inhibitors and with the combination of qingjiang white, the nitrate content of vegetables reduced by 13.21%-70.86% comparing to CK, and the yield increased by 3.45%-59.42%. Single applying three nitrification inhibitors,10% dicyandiamide was the best effect. As far as combination was concerned,10% dicyandiamide combined application was relatively better from overall performance.Among of them, adding three kinds of nitrification inhibitors (nitrification inhibitorsâ… +â…¡+â…¢treatments), the process of nitrating inhibition effect was the best.The residue of dicyandiamide research indicated that its degradation rate was 89.93% after applying 67days.