Effects Of Nitrogen Application On Soil Nutrients And Plant Nutrition In Larix Principis-rupprechtii Plantation

As one of the most important natural resources that human relies on, forests are a main component of terrestrial ecosystem saccounting for1/3of the Earth’s land surface. Larch gradually became important part of the boreal and other high altitude forests due to its characteristic cold and drought tolerance and rapid growth. North China Larch plantation grow well in the early stage. Meanwhile, some kinds of problems were caused by the single tree species for example poor biodiversity, poor ecological stability, increased pests, plantation soil degradation, and declined productivity. In this paper, we study effect of soil nutrients and plant nutrition characteristics of larch forests through inputting exogenous nitrogen, the results showed as followed:1. Under different nitrogen treatments, the concentrations of NH4-N in0-10cm soil layer were highest in August and lowest in June for the low nitrogen addition;and highest in August and lowest in June for the high nitrogen addition.In the10-20cm soil layer, the NH4-N concentrations were highest in August and lowest in October for the low nitrogen addition; and highest in August and lowest in October for the high nitrogen addition.Under different nitrogen treatments, the concentrations of NO3-N in0-10cm soil layer were highest in August and lowest in June for the low nitrogen addition; and highest in August and lowest in June for the high nitrogen addition. In the10-20cm soil layer, the NO3-N concentration s were highest in October and lowest in June for the low nitrogen addition; and highest in August and lowest in June for the high nitrogen addition.2. After two growing-seasons and treated by nitrogen supplement, there were no significant effect on the nitrogen content and organic carbon in soil. With exogenous nitrogen inputted, available phosphorous attenuated and available potassium leached loss.3. Nutrients contents in Larch leaf were higher than in fine roots. The effects of exogenous nitrogen inputted on nutrients contents in Larch leaf were significant.