Synergistic nitrogen fertiliser effects on nitrogen metabolism of wheat in saline-alkaline land

Abstract

In this study, a synergist made of itaconic acid, maleic acid, acrylic acid and other active ingredients polymerised was sprayed on the surface of nitrogen (N) fertiliser particles to make synergistic nitrogen fertilisers (SNF). To explore the effect of SNF on N metabolism of wheat in saline-alkaline land, five treatments were set up: CK – ordinary N fertiliser (299.86 kg N/ha); T1 – SNF (299.86 kg N/ha); T2 – SNF (239.89 kg N/ha); T3 – SNF (179.92 kg N/ha); T4 – SNF (119.94 kg N/ha). The aboveground dry weight of wheat, the photosynthetic characteristics of wheat flag leaves, the activity of the N metabolism enzyme of wheat flag leaves, the expression of N transporter-related genes in wheat roots, and the N accumulation and transport of plants were determined. The results showed that the T1 treatment performed the best. During the two years, the N translocation from stems and leaves to spikes of plants at maturity in T1 was 33.18–45.55% higher than that of CK. The N content of wheat spikes was 12.01–12.66% higher than that of CK. The activities of nitrate reductase, glutamine synthetase, glutamate synthetase and the expression of nitrate transporter gene TaNRT1.1 and ammonium transporter gene TaAMT1.1 were significantly higher than that of CK. The aboveground dry weight of wheat and photosynthetic characteristics of flag leaves were significantly higher than those of CK in T1, whereas the intercellular CO2 concentration was significantly lower than that of CK. The application of SNF positively affected N accumulation and transport in wheat, wheat yield, and fertiliser utilisation, as well as reduced N loss in saline-alkaline land.