杨树人工林对滴灌施肥的生长及生理响应研究

发布时间：2018-05-28 15:55

本文选题：杨树人工林 + 滴灌施肥　；参考：《中国林业科学研究院》2017年硕士论文

【摘要】：近年来,农林业生产经营中盲目的水肥供应造成的资源浪费以及生态环境污染问题日趋严重。发展滴灌栽培以及相应的水肥管理技术,可以在有效利用水分、养分资源的同时大幅度提高林地生产力,既能节约资源又能避免常规水肥管理造成的环境污染,符合现代林业的发展要求。本研究以滴灌栽培的6年生杨树人工林为研究对象,通过对8个施肥处理下(单株施N+P+K量分别为CK:0+0+0g,T1:72+12+36g,T2:108+18+54g,T3:144+24+72g,T4:180+30+90g,T5:216+36+108g,T6:252+42+126g,T7:288+48+144g)林木的生长和生理特性、细根的分布特征、林地生产力、土壤环境变化等方面研究不同施肥处理对杨树人工林的影响并提出滴灌栽培杨树人工林的优化施肥制度。主要研究结果和结论如下:(1)通过对不同滴灌施肥处理下杨树人工林的生长量进行测定,结果发现各施肥处理下不同月份胸径的生长动态与CK一致,6-8月份胸径的累计生长量占全年胸径生长量的82.9%-90.1%,滴灌施肥没有改变杨树人工林的季节生长模式。滴灌施肥能有效促进杨树人工林胸径(DBH)、树高和材积的生长,提高林分生产力,其中T6处理下胸径、树高和材积的年生长量最大,分别为2.2cm、2.07m和0.057m3/株,分别较CK提高44.1%、22.1%和50.9%。T1-T7各施肥处理的林地生产力均高于CK的25.31m3/hm2·a,分别是CK的1.14、1.22、1.24、1.33、1.38、1.51和1.34倍,其中T6处理下林地生产力大于T7处理,这说明施肥过量或施肥不足都会影响杨树的生长量,低施肥量对林木生长的促进作用大于高施肥量,过高的施肥水平并不能带来对应的产量的增益效应,要提高杨树的林地生产力还要考虑施肥以外的其它因素。(2)滴灌对细根的分布影响显著,滴灌条件(DI)下不同方向的细根长表现为株间(50.5%)对角(27.7%)行间(21.8%),差异显著;常规灌溉条件(CI)下的细根长也表现为株间(39.2%)对角(34.9%)行间(25.9%),但差异不显著;DI条件下不同方向的细根长均大于CI且差异极显著。滴灌影响细根的水平分布,DI条件下株间方向细根长在距树干0.5m处最大且与其他树干距离处差异显著,不同树干距离处均与CI有极显著差异;对角和行间方向与CI条件下细根的分布规律类似,细根长在距树干0.2m处最大,在距树干0.2m和0.5m处与CI有显著差异。滴灌影响细根的垂直分布,DI条件下株间方向细根长在0-10cm土层最大,对角和行间方向细根长的最大值均在10-20cm土层,CI条件下不同方向的细根长均表现为10-20cm土层最大;株间方向DI条件下的细根长在0-40cm土层与CI差异极显著,而对角和行间方向仅在0-20cm土层与CI有极显著差异。(3)滴灌施肥没有改变杨树人工林细根的垂直分布格局,不同施肥处理下杨树人工林的细根长在垂直方向上表现为0-10cm10-20cm20-30cm30-40cm,随土壤深度的增加细根分布减少。滴灌施肥显著影响杨树人工林细根的生长发育,不同施肥处理下的细根总长表现为随施肥量的增加不断增加,其中CK条件下的细根总长为3.02cm,T1-T7施肥处理下的细根长分别是CK的1.09、1.25、1.26、1.42、1.56、1.61和1.65倍。不同施肥处理下同一土层的细根长也均随施肥量增加而增大,0-40cm各土层的细根长表现为CK条件下最小,T1-T7各施肥处理下的细根长在0-40cm各土层分别是CK的1.04-1.68倍、1.13-1.69倍、1.15-1.67倍和1.05-1.56倍。通过对各施肥处理下林地土壤的调查研究表明,增加施肥量能有效提高土壤肥力,改善土壤条件,T1-T7各个施肥处理下土壤碱解氮、速效磷、速效钾含量均显著高于CK,不同施肥处理下土壤脲酶、磷酸酶、蔗糖酶的活性整体表现出随施肥量增加不断增大的特征。滴灌施肥能改善林地的土壤条件,进而改变林木对土壤水、肥的吸收能力,提高林地生产力。(4)滴灌施肥能提高叶片的净光合速率和蒸腾速率,6、7、8、9月T1-T7各施肥处理下的叶片的净光合速率分别是CK的1.16-1.54倍、1.04-1.21倍、1.03-1.34倍、1.05-1.30倍,蒸腾速率分别是CK的1.04-1.48倍、1.12-1.34倍、1.12-1.72倍、1.06-1.31倍,同步测定叶片的气孔导度、胞间CO2浓度等指标表明,滴灌施肥能在一定程度上增大气孔导度,有利于林木的光合作用和蒸腾作用。不同月份各施肥处理下净光合速率等生理指标表现出与CK类似的先增加后减小的特征,即6月份各指标的数值上升,7月份最大,随后在8月份开始下降,9月份最低。(5)对滴灌施肥不同施肥处理的施肥成本与林木生长所产生的经济效益进行边际效益分析,结果表明T6处理下单位面积的年收益最大,为23217 yuan/hm2,较CK提高41.5%。以CK为基准,各施肥处理的边际效益表现为T6T5T4T7T3T2T1,其中T6处理的边际效益最大,为6389元,是其他处理的1.37-3.69倍。T6处理下的杨树人工林能在满足杨树生长的同时获得最大经济效益,其对应的施肥量(252g/株N+42g/株P+126g/株K)即为滴灌栽培6年生杨树人工林的最优施肥水平。每年根据少量多次的原则施肥,从5月中旬开始,到8月中旬结束,分10次施完,其对应的施肥制度为滴灌栽培6年生杨树人工林的优化施肥制度,可以为今后滴灌培育杨树速生丰产林提供依据。
[Abstract]:In recent years, the waste of resources and the pollution of ecological environment caused by the blind water and fertilizer supply in the agricultural and forestry production and management are becoming more and more serious. The development of drip irrigation and the corresponding management technology of water and fertilizer can greatly improve the productivity of the woodland with the effective utilization of water and nutrient resources, which can not only save resources but also avoid the management of conventional water and fertilizer. The cause of environmental pollution is in line with the development requirements of modern forestry. In this study, the 6 year old poplar plantation of drip irrigation was used as the research object. Through 8 fertilization treatments (the N+P+K amount of single plant was CK:0+0+0g, T1:72+12+36g, T2:108+18+54g, T3:144+24+72g, T4:180+30+90g, T5:216+36+108g, T6:252+42+126g, T7:288+48+144g). The effects of different fertilization treatments on Poplar Plantation and the optimal fertilization system of Poplar Plantation in drip irrigation were studied. The main results and conclusions were as follows: (1) the growth of Poplar Plantation under different drip irrigation treatments was carried out. The results showed that the growth dynamics of DBH in different months was the same as that of CK. The cumulative growth of breast diameter in 6-8 months accounted for 82.9%-90.1% of the annual DBH growth. Drip irrigation did not change the seasonal growth pattern of poplar plantation. Drip irrigation could effectively promote the diameter of Poplar Plantation (DBH), tree height and volume growth. In the high forest productivity, the annual growth of DBH, tree height and volume was the largest, which were 2.2cm, 2.07M and 0.057m3/, respectively, increased by 44.1%, respectively, compared with CK, and the productivity of 22.1% and 50.9%.T1-T7 were higher than 25.31m3/hm2. A of CK, which were 1.14,1.22,1.24,1.33,1.38,1.51 and 1.34 times of CK respectively. Productivity is greater than T7 treatment, which indicates that excessive fertilization or insufficient fertilization will affect the growth of poplar, and the effect of low fertilization on forest growth is greater than that of high fertilization. The high fertilization level does not bring the corresponding gain effect, and other factors other than fertilization should be considered to increase the forestland productivity of poplar. (2) drip irrigation. The influence of the fine root distribution was significant. The fine root length of the different directions under the drip irrigation condition (DI) was shown in the Interplant (50.5%) diagonal (27.7%) interline (21.8%), and the fine root length under the conventional irrigation condition (CI) was also displayed in the Interplant (39.2%) diagonal (34.9%) interline (25.9%), but the difference was not significant; the fine root length of different directions under the DI condition was greater than that of CI and the difference was different. Extremely significant. Drip irrigation affects the horizontal distribution of fine roots. Under DI conditions, the direction of fine roots is the largest in the distance from the trunk of tree trunk and at the distance from the other trunk, and the distance from the tree trunk is significantly different from that of the CI; the distribution of the diagonal and intercourse direction and the fine roots under the CI condition is similar to that of the trunk of the tree, which is longest in the trunk of the trunk of the tree and in the trunk of the tree at the distance from the trunk of the tree. 0.2m and 0.5m have significant differences from CI. Drip irrigation affects the vertical distribution of fine roots. Under DI conditions, the fine roots are the largest in the 0-10cm soil layer, and the maximum value of fine roots in diagonal and intercropping direction are all in the 10-20cm soil layer. The fine roots of different directions in the CI condition are the largest in the 10-20cm soil layer, and the fine roots under the Interplant direction DI are long in 0-40cm soil. The difference between layer and CI was very significant, but the direction of diagonal and intercourse was very significant difference between 0-20cm soil layer and CI. (3) drip fertilization did not change the vertical distribution pattern of fine roots of poplar plantation. The fine roots of poplar plantations were 0-10cm10-20cm20-30cm30-40cm in the vertical direction under different fertilization treatments, and the fine root distribution increased with soil depth. The growth and development of fine roots of poplar plantations were significantly affected by drip irrigation. The total length of fine roots under different fertilization treatments increased with the increase of fertilization, of which the total length of fine roots under CK was 3.02cm, and the length of fine roots under T1-T7 fertilization was 1.09,1.25,1.26,1.42,1.56,1.61 and 1.65 times of CK respectively. The fine root length of the soil layer increased with the increase of the amount of fertilizer. The fine root length of each 0-40cm soil layer was the smallest under the CK condition. The fine roots under the T1-T7 fertilization treatment were 1.04-1.68 times that of CK, 1.13-1.69 times, 1.15-1.67 times and 1.05-1.56 times respectively. Fertilization can effectively improve soil fertility and improve soil conditions. The contents of soil alkali hydrolysable nitrogen, available phosphorus and available potassium are significantly higher than that of CK under the treatment of T1-T7. Soil urease, phosphatase and invertase activity in soil under different fertilization treatments are characterized by the increase of the amount of soil urease, phosphatase and invertase as a whole. Drip fertilization can improve the soil strip of woodland (4) the net photosynthetic rate and transpiration rate of leaves were increased by drip irrigation, and the net photosynthetic rate of leaves under 6,7,8,9 month T1-T7 was 1.16-1.54 times of CK, 1.04-1.21 times, 1.03-1.34 times, 1.05-1.30 times, and the transpiration rate was CK 1.04-1., respectively. 48 times, 1.12-1.34 times, 1.12-1.72 times, and 1.06-1.31 times, simultaneous determination of the stomatal conductance of leaves and the concentration of CO2 in the cells showed that the drip fertilization could increase the stomatal conductance to a certain extent, and was beneficial to the photosynthesis and transpiration of the trees. The physiological indexes, such as net photosynthetic rate under different fertilization treatments in different months, showed a similar increase to CK. The characteristics of the addition decrease, that is, the value of each index rose in June, the largest in July, then in August and the lowest in September. (5) the marginal benefit analysis on the cost of fertilization and the economic benefit produced by the growth of forest trees was analyzed. The results showed that the annual income per unit area under the T6 treatment was the maximum, which was 23217 yuan/hm. 2, compared with CK, the marginal benefit of each fertilizer treatment was T6T5T4T7T3T2T1 on the basis of CK, and the marginal benefit of each fertilizer treatment was T6T5T4T7T3T2T1, of which the marginal benefit of T6 treatment was 6389 yuan. It was the other treated Poplar Plantation under the 1.37-3.69 times of.T6 treatment to obtain maximum economic benefits while meeting the growth of poplar, and its corresponding amount of fertilizer (252g/ strain N+42g/ strain P+126g/). Plant K) is the optimal fertilization level for the 6 year old Poplar Plantation in drip irrigation. According to a small number of principles of fertilization, starting in mid May and ending in mid August, the fertilizing system is completed in 10 times. The corresponding fertilization system is the optimal fertilization system for the 6 year old Poplar Plantation in drip irrigation, which can provide the poplar fast-growing and high yield forest with drip irrigation in the future. Basis.
【学位授予单位】：中国林业科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S792.11

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