Effects Of Fertilization On Rhizome Growth Of Leymus Chinensis

In this paper, by means of two successive years of fertilization and research of rhizome growth on Leymus chinensis in the wild, we discussed the effect of different treatments on morphology, growth of underground rhizomes and ecological response. The experiment used five treatments which was N. P, K, NPK and Control, and each treatment had three parallel sample. The research was divided into two parts, the rhizome growth of seasonal dynamic test and the alkali spot invasion test. Through the observation and statistics of the morphological characteristics(leaf, tiller, rhizome) of architecture, density of the old and new rhizome, the spatial pattern, such as diameter, branch angle, node density and biomass, the analysis results were as follows:1. The annual average change of old rhizome density in 2009 was as follow:NPK >P>N>K>CK. Each treatment had significantly improvement compared with control, treatment N, P, K and NPK improved 57.5%,91.0%,34.9%and 111.0% respectively. The annual average change in 2010 was as follow:P>NPK>CK>N>K, treatment P and NPK increased 113.9%and 38.3%compared with control. The old rhizome density in NPK and N had the same change trend, and the volatility of other treatments in 2009 ware not obvious, while the seasonal dynamic in 2010 had the different trend change, especially during the 7-9 months, the v-shaped change appeared most obviously.The annual average change of new rhizome density in 2009 was as follow:group K and NPK had the same change rule, which reached the peak value in July and then began to reduce until extinction. The new rhizome in control appeared only in May, the N treatment in June and August, the P treatment in June, September and October, the K treatment in June to September, and the NPK treatment in June to August. But the number of new rhizome were too less to discuss.2. Fertilization promoted the growth of node density in 2009, the group N and NPK showed the only peak change trend, group P had a fluctuation change group K was declining. The annual average was NPK>P>N>CK>K, group NPK,P and N increased 31.1%,19.7%and 8.8%in turn, but there had been no increase in K, or even decline. The node density had the volatility change in 2010, and the annual average was P>NPK>CK>K>N. The group P and NPK increased 72.3%and 23.9%compared with control, while the group K and N decreased, and the effect of fertilizer was not obvious.3. Fertilization promoted the growth of rhizome. The effect of group N was the. most significant, appeared the high-low-high change trend in 2009 experiment. While the fluctuation change of diameter was great, which showed a multi-modal fluctuation state change trend and appeared a high-low-high-low trend? The diameter in group N was the highest in 2009 and group NPK was the highest in 2010.4. Fertilization promoted outer-plane changes of branch Angle. The change of branching Angle was great in the early period, and then began to decrease gradually The annual change of branching Angle in 2009 was NPK>P>N>K>CK, while the branching Angle in 2010 was N>K>NPK>P>CK, and the value in 2010 was higher then in 2009.5. Fertilizer processed the biomass. Group P and NPK had two obvious process which was of value-added and impairment throughout the growing season in 2009. The effect in group N and K was significant in the early period and not obvious in the later period. The effect of group P and NPK was prominent, and the group N and K also helped the accumulation of biomass, but the effect of group N was a little. The successive two years'results showed many differences, on the one hand, the starting and ending time was earlier in 2010 than 2009. On the other hand, because of the growth rhythm of plant itself and the season interweavement, the root biomass had the fluctuation.6. Fertilizer treatments significantly promote the growth of the rhizomes density. The annual change in 2009 was NPK>P>N>CK>K, the effect in group K alone was not obvious and with the help of N and P the effect was evident. The change of seasonal dynamic waved greatly, appeared v-shaped change from July-September in 2010. The density of old rhizome and node density had the similar rule. The annual change in 2010 was P>NPK>N>CK>K and by simulating equations showed that the relationship between rhizome and old rhizome density had significantly linear correlation7. Fertilization treatment on the influence of the leaf density was very significant (p < 0.01). In 2009 the leaf density of different fertilizer treatments showed the similar change trend.The annual change in 2009 was NPK>N>P>K>CK. Different fertilizer treatments had fluctuated change in 2010, and appeared apparent v-shaped change, the annual change in 2010 was P>NPK>N>CK>K. The differences of the two years' leaf density were great and the rules were not clear.8. In alkali spot invasion experiment, because of the volatility of the season, the two year's rules had many differences. In the test of 2009, the annual change of total rhizome density, node density, tiller density and rhizome density were the largest in group P. The branch Angle was the largest in group N. In the test of 2010, the total rhizome density, node density, and the rhizome density were the largest in group NPK, while the branch Angle was the largest in group N.