Effect Of Mowing Frequence And Defoliation Instensities On The Form Of Growth And Nutritionnal Quality Of Amorpha Fruticosa

The one of main use of the grassland is mowing. Moderate mowing can promote tillering and regeneration of plants, and increase the aboveground part biomass and nutrient elements N, P and K content, while improving accumulation of crude protein, crude ash and carbohydrate of forage, and reducing content of the acid detergent fiber, improved the nutritional quality and forage palatability. According to the growth characteristics of Amorpha fruticosa, setting the artificial mow times (1,2,3times) and artificial defoliation intensity20%,40%,60%,80%,100%(accounting for ratio of the aerial parts), studying of the effection of growth height, biomass, plant stems, leaves nutrients and phosphorus and potassium content of A. fruticosa, The main conclusions are as follows:The impact of different mowing frequency on the aerial parts of A. fruticosa is promoting the growth from May to September in rapid growth period of A. fruticosa by the appropriate times of mowing. Average plant height and crown of one time is120and117cm,and twice is100and90cm, three times is65.7and66cm. The number of branches, branches increased with the increase in the times of mowing, mowing one time only15, and mowing twice and three times, the number of branches is26and28; Biomass accumulation was significantly higher, including fresh weight602g of per plant by mowing twice, significantly higher than other treatments;To improve its nutritional quality, crude protein content increased with the increased frequency of mowing, the highest content of up to22%of leaves; Neutral detergent fiber, acid detergent fiber decrease with the increase in the times of mowing, to improve the palatability and digestibility of livestock feed. But soluble sugar content is significantly reduced with the increase in the times of mowing, it is to reduced to2.3%in stem processed by mowing three times, so it is indicating that many times mowing isn’t conducive to the accumulation of soluble sugar. Therefore, a comprehensive comparison of various factors, the appropriate times of mowing in rapid growth period of A. fruticosa is twice.Different defoliation intensity on Amorpha growth significantly, moderate defoliation (defoliation intensity is less than50%) can promote the growth of A. fruticosa and its nutritional quality, and on the contrary over-defoliation (defoliation intensity is greater than50%) can restrain of the growth, plant height is reduced as the defoliation intensity increases, moderate defoliation of20%and40%was significantly higher than the over-defoliation by80%and100%(P<0.05), the plant height of moderate defoliation was100cm, while the intensity of100%processing plant height of34cm. Crown diameter and plant height were similar to moderate defoliation, crown diameter of moderate defoliation was greater about100-120cm, over-defoliation reduced to70cm; moderate defoliation is also conducive to the increase of the secondary branches, the number of secondary branches of moderate defoliation was from20to50, over-defoliation was from20to40, then reduced to35.5groups of simulation defoliation intensities on A. fruticosa,20%,40%,60%,80%, and100%proportion of aboveground vegetation part were made to study the influences of nutritional quality of Amorpha fruticosa by different defoliation intensities treatment.7nutritional index: crude ash (ASH), neutral detergent fiber (NDF), acid detergent fiber (ADF), water-soluble sugar (WSC), crude protein (CP), phosphorus (P), potassium (K) were comprehensive analyzed using grey correlation degree method The results showed that when the defoliation intensity of Amorpha fruticosa is on40%, the weighted grey correlation degree of leaves and stems are0.7812and0.6513, respectively, which is greater than other defoliation intensities treatments, A. fruticosa has the best nutritional value on defoliation intensities treatment of40%.Defoliation intensity is of about40%, the moderate defoliation does not affect the the normal growth of A. fruticosa, after an appropriate amount of defoliation, the stalk continues to grow new branches, so that both increased stem, leaf production, but also to accumulation of nutrients in leaves and stems. So to get the best the nutritional quality of A. fruticosa, it is that appropriate defoliation intensity must will to be controlled below40%.