Regulation Of Agronomic Measures On The Growth And Development Of Glycyrrhiza Uralensis

The field experiment on the cultivation methods, irrigation, fertilization, transplanting density of G.uralensis were taken in Minqin County from 2006 to 2007 to study the regulating effect of agronomic measures on the growth and development of G.uralensis and the growth law of G.uralensis. The purpose of the study was to provide some key technologies and some theoretical foundations for the high efficient planting of G.uralensis. Thereby,guiding the large-scale production for standardization cultivation of G.uralensis. The main results were as follows:1. The film mulching cultivation had significant effect on plant height, main root growth, root diameter and the number of branches. The results showed that the plant height, main root length, root diameter and the number of branches of film mulching cultivation were higher than the unmulched hole sowing cultivation 5.51%, 7.1%, 2.17%,and 10.21% respectively, and were higher than the drill seeding in unmulching field (the CK) 10.30%,11.6%,9.48% 15.65% respectively. The change trend of all growth indicators of one year old G.uralensis were similar with two years old G.uralensis. The Mechanism that film mulching cultivation improved the growth and development of G.uralensis, was the film mulching increased the soil temperature by 0.8℃to 2.65℃, and the water use efficiency increased too. In addition, single dry matter accumulation and yield of the mulch treatment was obvious higher than the unmulched hole sowing cultivation and the drill seeding in unmulching field. The yield of one and two years old G.uralensis mulched with film were higher than CK about 39.87% and 22.92%.2. The irrigation had significant effect on agronomical characters,dry matter accumulation and yield of G.uralensis. Dynamic change trend of agronomical characters of G.uralensis were similar under different irrigation treatment. When irrigation was below six times and the total maximum irrigation was below 5400m~3/hm~2, the yield of G.uralensis was increased with the increase of irrigation. While the yield of G.uralensis was decreased when irrigation increased above maximum irrigation.What's more, Agronomical characters of G.uralensis were increased with irrigation increase at optimum irrigation range. Thereby, all parts dry matter accumulation of G.uralensis were increased with irrigation increase and promoted its yield as well. When irrigated 5 to 6 times, namely, the total of irrigation 4500 m~3/hm~2 to 5400m~3/hm~2, not only agronomical characters but also dry matter accumulation and yield were the best.3. Fertilizer had significant effect on the yield by area of G.uralensis. the change trend to the yield of G.uralensis was from high to low with the nitrogen, phosphorus and potassium increase. The lower fertilizer rate had certain promotion function on the yield of G.uralensis. While the yield had no obviously increase when the fertilizer rate reached a certain level. Fertilization had more obvious effect on one year old G.uralensis than two years old. The discipline of dry matter accumulation was that nitrogen, phosphorus and potassium fertilizer amount had different effect on dry matter accumulation of G.uralensis with different growth periods. The general trend was that dry matter accumulation up-ground was faster than below-ground before August, Which was conversed from August to October. The comprehensive analyzing results showed that the optimum amount of fertilization was N 67.5~101.79 kg /hm~2, P205172.5~260.13 kg /hm~2, K2O162~243 kg /hm~2.4. The transplanting density had different effects on the growth dynamics of G.uralensis. The plant height, root diameter, main root length and the number of stem-branch of G.uralensis increased with the growing process. 270.000plants/hm~2 was suitable transplanting density to the plant height and root diameter. Two-year-old G.uralensis root length had similar growth dynamic under different transplanting density, while the main root was longer and a number of branches were more than the others with low transplanting density. The general trend of total dry matter accumulation were that the lower the transplanting density, the greater dry matter accumulation. The single plant up-ground dry matter accumulation was the highest under transplanting density of 240,000plants/hm~2, which was 24.98g/plant. While under transplanting density of 270,000plants/hm~2, root dry matter accumulation was the highest, which was 50.12g/plant. Therefore, transplanting density was an important impact on plant growth and yield formation. From this study, the conclusion can be drawn that transplanting density of 270,000plants/hm~2 was suitable for the local G.uralensis root yield.