Study On Cultivating Strong-drought Resistant Nitraria Tangutorum Under Na Compound Fertilizer, Na And Si Interaction

Nitraria tangutorum is one of dominant constructive species in the northwest desert regions of China. It plays important roles in wind breaking and sand fixing and has high ecological and economical values. However, due to human excess exploration and the continuing deterioration of the environment, this wild resource plants have begun to grow poorly and die of a large area. Recent studies have shown that Na plays important roles in improving desert plant growth and enhancing drought resistance and successfully developed a kind of desert fertilizer Na compound fertilizer. Furthermore, numbers of studies found that Si also plays an important role in the promotion of plant growth and increase resistance of plants. Based on above works, this paper studied the growth and drought-resistant effects of N. tangutorum under the application of and NaCl and Na2Si03 interaction through pot method in field. The main results are as follows,1. Na compound fertilizer significantly advanced the growth and biomass of N. tangutorum, and the effects in shoot was better. Compared with control and application of (NH4)2HPO4 (with the same nitrogen and phosphorus level of Na compound fertilizer), the application of Na compound fertilizer increased plant height by 109% and 45%, root length by 95% and 57%, main stem diameter by 83% and 43%, main root diameter by 85% and 22%; shoot fresh weight by 272% and 81%, root fresh weight by 170% and 49%, decreased root to shoot ratio by 38% and 21%, respectively.2. Na compound fertilizer significantly increased Na content and Na/K ratio in shoot of N. tangutorum. Compared with control and application of (NH4)2HPO4, the application of Na compound fertilizer increased shoot Na content by 49% and 24%, root Na content by 14% and 11%, shoot Na/K ratio by 62% and 30%, respectively. At the end growth period,11% of Na content of Na compound fertilizer was absorbed by N. tangutorum,67% of Na fertilizer was left in the potted soil, which could be absorbed by plant in the following years, futher enhancing the growth and drought resistance of N. tangutorum.3. For single NaCl treatment, with the increase of NaCl application, the growth and biomass of N. tangutorum increased gradually. Compared with no fertilizer utilization,20.5μmol/g NaCl treatment increased N. tangutorum's height, root length, shoot and root fresh weight by 47%,25%,332%and 148%, respectively, decreased root to shoot ratio by 69%, increased shoot Na content by 91%, and decreased root Si content 7%. The left Na, K and Si content in soil increased with the increase of NaCl application.4. The application of Na and Si interaction also improved the growth of N. tangutorum, especially 0.1μmol/g NaCl+2.5μmol/g Na2SiO3 treatment had the best improvement. Compared with 5.1μmol/g NaCl treatment,0.1μmol/g NaCl+2.5μmol/g Na2SiO3 increased N. tangutorum's height, root length, shoot and root fresh weight by 81%,43%,192%and 120%, respectively, decreased root to shoot ratio by 36%, decreased shoot Na content by 63%, and increased root Si content by 78%. The left Na, K and Si contents in soil of Na and Si interaction were all higher than those of NaCl application. All those results showed that appropriate Na and Si interactive application more promoted N. tangutorum's growth and drought-resistance than single NaCl application.