| Masson pine had so many fine features which was adaptable soil and cli mate, fast- growing, high yield, high degree of utilization of the whole tree, fi ne fiber and so on.It's very widespread. It's an important industrial wood and afforestation species. Over the years, scholars had little research on the aspec t of nutrition characteristics thoroughbred. N, K were necessary to large numb er of elements for plant growth. It's important to ascertain their impacts on t he growth of Masson pine. The superior provenances had the characteristics o f high-speed growth. It's also significant to clarify the affecting which was th e absorption change of mineral nutrients of excellent provenances by exogeno us N, K factors. At present, most scholars had studied the effect of phosphor us for provenances, but the research of the N, K effect of thoroughbred was still missing. And the present study was to solve the above proble ms, clarifyi ng the interaction between nutrients of Masson pine seedlings, and cultivating the high- quality seedlings, and passing the fertilizer to improve the survival r ate of Masson pine's plantation, and provid ing a theoretical basis for the esta blishment of fast- growing high-quality Masson pine timber. It's though fertilizi ng the different levels of N, K fertilizer respectively of six provenances whic h was Chongyi Jiangxi, Duyun Guizhou, Gupeng Guangxi, Shaoguan, Guang dong, Shanghang Fujian and Tongmian Guangxi to observe the N, K use effi ciency and absorption change of nutrients of six provenances. And achieved t he following results:1. The N fertilizer use efficiency of different excellent provenance of Masson pineThe provenances of Duyun, Shanghang and C hongyi were more tolerant of poor(the growth remains unaffected on the CK level) and the seedlings was the most robust, so fertilizer could be a good promotion to its growth of height and diameter. The provenance of Tongmian had the characterist ic of hi gh-speed growth, especially in the high- nitrogen environment(87g/m2). N itroge n fertilization had more promoting effect on the height growth than the stem growth of the provenance of Gupeng. Its optimum levels of nitrogen fertilizer was 44g/m2. And Shaoguan provenance was not prominent in the growth ind icators compared with other provenances, however, its diameter's growth was so rapid in 44g/m2 level which was also the smallest of ratio of height and d iameter and most robust seedlings. Because of t he different requirement of the fertilizer by various provenances, it should be based on the purpose of affor estation and site conditions to select the appropriate seed and determine the a mount of nitrogen in order to improve the efficiency of Masson pine growth to achieve the maximum efficiency use in the actual use of the production.2. The K fertilizer use efficiency of different excellent provenance of Masson pineAfter the application of different levels of K fertilizer, different provenan ces of Masson Pine exhibited the different growth differences. Wherein 18g/m2 level could promote the aboveground growth of Tongmian source, and the 72g/m2 could also promote its underground growth. Gupeng provenance's above ground growth was the best at 18g/m2 level which could promote the undergr ound growth,too. Duyun provenance had a good expression of aboveground gr owth at 36g/m2 and 18g/m2 level and of growth of roots at 72g/m2 level. Sha nghang Provenance which had a better expression on growth of height, diamet er, and roots at 72g/m2 was the most potassium required. The different potass ium fertilizer was not benefit to the growth of aboveground part in Shaoguan provenance. The 9g/m2 and 36g/m2 level could promote aboveground growth of C hongyi provenance, while the 72g/m2 and 18g/m2 level could promote th e growth of diameter but inhibit the growth of height. To sum up, the Gupen g and Tongmian provenances were more resistant to stress factors K. And the growth of height and diameter of Masson pine were more sensitive at 18g/m2 level, but various sources of K element had efficiency quite differently.3. Nutrient absorption status of Masson pine of different provenance under dif ferent N fertilizer levelsAmong different excellent provenance, Ca content of all provena nce was the highest among 9 mineral elements, except N content was second in Tong mian. K content was second in other provenance. Then the order of P, Mn, Cu and Zn had no significant difference, but the content of N, K, Mg, Fe ha d difference. About the nutrient in stem, the element content order of Shangh ang, Gupeng, C hongyi was:Ca>P>Mg>N>K>Fe>Mn>C u>Zn, and the order of Tongmian and shaoguan was Ca>P>Mg>K>N>Fe>Mn>C u>Zn, and the order o f Duyun was P>Ca>N>Mg>K>Fe>Mn>C u>Zn. The nutrient content in leaf sh owed that P content was the highest in Duyun, Tongmian and Shaoguan. Mg content was the second; Ca content was the highest. In Shanghang, Gupeng and Chongyi provenances, the P content was the second and the contents of different nutrient elements were almost the same in these three provenance. T o sum up, the microelement content of masson pine had significant difference in different provenance, and the content of microelement had almost the sam e. We can through understand the nutrient absorption status of diffe rent excell ent provenance under different fertilizer levels to provide reliable basis to the choice of seed and planting site.4. Nutrient absorption status of Masson pine of different provenance under dif ferent K fertilizer levelsThe different element nutrient content was main Fe and Mg content in th e root of Masson pine, and the order of Duyun, Shanghang, Tongmian and C hongyi Provenance's elements was Ca>K>Mg>Fe>N>P>Mn>C u>Zn, while Fe content was higher than Mg content in Shaoguan and Gupeng provenance. Th e different element nutrient content was main Cu and Zn content in the stem, wherein the Zn content was higher than C u content in the Duyun, Tongmian, Shaoguan and Gupeng provenances, while the Shanghang and C hongyi prove nances were on the contrary. The K content was the most in the leaves of di fferent provenances, and followed the content of Ca, and N elements again, w hile the order of Duyun provenance of nutrient element contents was different compared with other provenances for K>Ca>N>P>Fe>Mg>Mn>Zn>C u. The d ifference of other provenances were C u and Zn content. To sum up, different concentrations of K fertilizer could improve the K element 's absorption in th e roots and leaves, but it was not conducive to P element's uptake, while pro moted the P element's uptake in the stem.5. The relationship among the nutrient absorption, the growth and fertilization of Masson pineNitrogen fertilization could facilitate the absorption of N in Masson pine greatly, while the K fertilization could promote the absorption of K in Masso n pine. Under the different levels of fertilizer, the relationship between growth indexes and nutrient levels of Masson pine was negative, which suggested th at the reducing of content of mineral nutrient elements would lead to reduce the plant growth. It manifested in the growth of height, diameter and accumul ation of biomass. |
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