5. Conclusions
It took nearly 10 years to conduct a field experiment of N addition onL. chinensis in MSSL. Nitrogen addition not only increased the
contents of protein and fat, the ratio of
K+/Na+ and
Ca2+/Na+ of L. chinensisshoot, but also decreased the degree of soil salinization and increased
soil fertility and the EMF. The suitable N addition rate of 90-120 kg N
ha-1 effectively inhibited the yield, quality and soil
degradation of L. chinensis in MSSL. Thus, scientific data once
again proved that N addition was an effective and necessary measure to
maintain the healthy growth of L. chinensis and inhibit land
degradation in saline-sodic grassland of northern China.