| Pinus massoniana is widely distributed in Guizhou,it is growth in acid yellow soil.The yellow soil is the most widely distributed and the largest area of soil type in Guizhou province,and its mineral nutrients is generally low,the calcium and magnesium in soil are prone to run off particularly.The imbalance of nutrient elements will affect growth of plants.There are nearly 1/4 pinus massoniana forests are low yield and low efficiency forest in the south of China,which may be related to different soil types,people didn't comply with the principle of matching site with trees.A lot of studies have proved that phosphate fertilizer could promote the growth of Pinus massoniana,the application of phosphate fertilizer is mainly calcium magnesia phosphate,which is a kind of calcium,magnesium,phosphorus element fertilizer.However,we did not see some reports about exogenous calcium and magnesium in growth and mineral nutrients absorption of pinus massoniana.Therefore,in this paper,Fujian Shanghang,Guizhou duyun,Guangxi Gu Peng,Jiangxi Chongyi,Guangxi Tongmian a total of 5 provenances of 1-year seedling as the research objects,the experimental had studied of 5 levels of calcium and magnesium fertilizer,which was conducted to find out the growth and absorption of elements in different provenances,the main results were as follows: 1.The growth and nutrient of excellent provenances of pinus massoniana in different calcium fertilizer levels ? Seedling growth calcium fertilizer had different effects on the growth of pinus massoniana Seedlings.the appropriate amount of calcium promoted the growth of the seedlings of Shanghang and Gupeng provenance,high fertilization is unfavorable to its growth;and the optimum fertilization level was 28 g/m2.(1)Seedling height and ground diameter:compared with the control,under the 14 g/m2 level,calcium could promote seedling growth of Gupeng,Chongyi,Tongmian provenances,calcium inhibited seeding growth of shanghang and Duyun provenances;when the fertilizer rate reached more than 28 g/m2 level,the effect of calcium on the growth was weakened,and even the growth of seedlings were inhibited.Calcium significantly promoted growth of diameter of Shanghang,ground diameter of the rest of the provenance growth had different degree of inhibition.(2)Root characteristics: in the exuberant growth period,compared with the control,calcium promoted the growth of root length,root surface area,root tip number and root volume,mean diameter had not changed;during the growth stop period,calcium promoted the growth of root length and the number of root tips,high fertilizer application was unfavorable to the growth of root system.(3)Biomass characteristics: in the exuberant growth period,the high fertilization rate was unfavorable to the biomass accumulation.During the growth stop period,calcium promoted the accumulation of biomass of Shanghang and Tongmian provenances,and inhibited seedlings aboveground biomass accumulation of Duyun,Gupeng,Chongyi provenances.The total biomass of the seedlings of Different Provenances was Shanghang>Tongmian>Gupeng>Duyun>Gupeng.? Nutrient characteristics There were differences in the accumulation of 9 kinds of elements in the Masson Pine Seedlings of different provenances and their responses to exogenous calcium.Calcium promoted the accumulation of nutrient elements in of Duyun and Shanghang,and the optimum fertilization level was 28 g/m2.those elements content in different organs were leaf > root > stem,the content and distribution of elements were as follows:(1)Macroelement: in the exuberant growth period,calcium promoted the accumulation of accumulation in leaves.During the growth stop period,calcium inhibited accumulation of macroelement in leaf.there was no consistent rule of calcium to the changes of the macroelement in the stem and root.The content of nitrogen in root and stem and leaf of Shanghang provenance was than others;calcium had no influenced on the content of phosphorus in root and stem and leaf,which was not obvious;the content of K of Duyun,Gupeng provenance in root and stem and leaf than others.(2)Middle-element: during the growth stop period,calcium promoted the accumulation of Ca in different provenances in leaves and stem,calcium was not consistent with the accumulation of Ca in roots.Calcium promoted the accumulation of Mg in leaves and stems of Shanghang and Duyun,calcium inhibited the accumulation of Mg in root of Shanghang provenance,calcium was not consistent with the accumulation of Mg in the other Provenances.The content of middle-elements in the stem and leaf of Shanghang was higher than others,the root medium element was the least.(3)The trace elements: in control,during the growth stop period,calcium promoted the accumulation of Fe in leaves and stems of different provenances,there was no obvious effect on Fe in root of different provenances.The effect of calcium on Mn,Cu,Zn contents were not consistent.The trace elements were relatively higher in Duyun provenances.2.The growth and nutrient of excellent provenances of pinus massoniana in different magnesium fertilizer levels ? Growth magnesium fertilizer had different effects on the growth of Pinus massoniana Seedlings.the low amount of magnesium promoted the growth of the seedlings of Gupeng and Shanghang provenances,high fertilization was unfavorable to its growth;magnesium inhibited growth of Duyun and Chongyi and Tongmian provenance.the best fertilization level was 42 g/m2.(1)Seedling height and ground diameter: compared with CK,magnesium promoted the growth of Shanghang provenances seedlings,the effect of magnesium on the growth of other provenances was inhibited in different degrees,especially,the growth inhibition of Duyun provenances seedings was the most obvious,when the level of 85 g/m2 was reached,the growth inhibition of the seedlings was enhanced gradually.For ground diameter,compared with CK,at 42 g/m2,85 g/m2 level,magnesium promoted the growth of ground diameter of different provenances;when more than 170 g/m2,magnesium promoted effect on the growth of ground diameter decreasing,even the suppression of diameter growth.(2)Root characteristics: in the exuberant growth period,compared with CK,root indexes were growth of Shanghang,Duyun,Chongyi,Tongmian provenances of pinus massoniana seedlings by different levels of magnesium,magnesium inhibited the growth of root of Gupeng provenance.During stop growth period,compared with CK,the root length and root surface area of Pinus massoniana seedlings were inhibited by different levels of magnesium,with the increase of fertilization amount,the stronger the inhibition.(3)Biomass characteristics: in the exuberant growth period,compared with CK,the effects of different levels of magnesium promoted biomass on the aboveground and the total biomass of Duyun.During the growth stop period,magnesium also contributed to the accumulation of biomass of Shanghang and Gupeng,there was no consistent rule for the accumulation of biomass in other parts.The total biomass of seedlings of other provenances mean order was Shanghang>Duyun>Gupeng> Tongmian>Chongyi.? Nutrient characteristics magnesium fertilizer had different effects on the nutrient uptake of Pinus massoniana Seedlings.Duyun and Shanghang provenances have accumulated more nutrients.the best fertilization level was 42 g/m2.The content of each organ in the seedling were leaf>root>stem,the content and distribution of nutrient elements as follows:(1)Macroelement: during the growth stop period,magnesium inhibited N accumulation in leaf and stem,magnesium promoted the accumulation of N in roots,the accumulation of N of Shanghang and Gupeng was inhibited by high dosage;magnesium promoted the accumulation of P of Gupeng,but the change was not obvious.Magnesium inhibited K accumulation in root and stem and leaf(except for Shanghang),there was no consistent pattern of K accumulation in stems.The accumulation of N Shanghang and Duyun was higher than other provenances,P accumulation of Duyun and Gupeng provenance was most,accumulation of K of Chongyi was most.(2)Middle-element: during the growth stop period,Magnesium promoted the accumulation of Ca in stems and leaves of Pinus massoniana provenances,with the increase of fertilization amount,there were different degrees of increase,which Duyun and Chongyi provenances accumulated Ca more;magnesium promoted the accumulation of Ca in roots of Tongmian,while inhibited the accumulation of Ca in the other provenances,with the inhibition effect of high fertilization.Magnesium promoted the accumulation of Mg in root and stem and leaf(except for Shanghang).(3)The trace elements: during the growth stop period,magnesium promoted the accumulation of Fe in stems and leaves,the Fe accumulation was inhibited in roots,high fertilization was not conducive to the accumulation of Fe.Magnesium promoted the accumulation of Cu and Zn in stems and leaves,the Mn accumulation was inhibited in roots(except for Chongyi and Tongmian),the effects of magnesium on the accumulation of Cu and Zn in different provenances were not consistent,there was no significant effect on Zn accumulation in stems. |
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