| Chinese fir as an important timber tree species in China are widely planted in the southern area of the Yangtze River and Qinling Mountains.With the characteristics of fast growth and high economic value, it is one of the preferred tree species to build fast growing and high yield forest in the southern mountainous region of China.However, a large number of studies have indicated that the soil fertility of Chinese fir forest have shown a declining trend.Fertilization is one of the important ways to accelerate the growth and development of plants. It has important significance to improve soil fertility, promote the growth of trees, and achieve the goal of fast growing, high quality and high yield.However the traditional fertilization method while in the short term usually acts fast, but it cannot last a long time,and the crop’s absorption capacity is limited, after fertilization in a short time nutrients is difficult to be completely absorbed, resulting in a imbalance between fertilizer releasing nutrient and crop requirement. Bag-controlled fertilizer has achieved good results in solving the problem of low nutrient utilization.Bag-controlled release fertilizer is one of the highest scientific and technological content in the world. It has become an important direction of the development of fertilizer in our country and the world, and it is also one of the key technologies extension of the national Ministry of Agriculture.So, this study takes Shunchang County, Nanping City, Fujian Province Yangkou National Forest Farm’s experimental forest as an example and continuously tests the soil nutrient content, leaf nutrient content and soil properties before and after fertilization plots in four years to study the effects of different fertilization methods on the growth of 6-year-old Chinese fir.In order to explore a fertilization mode that can improve of Chinese fir production potential,the wood quality and promote the growth of the economic benefits of Chinese fir provide a scientific basis and theoretical guidance.The results showed that:I The effects on Chinese fir growth amounts of fertilization Analysis on the growth of Chinese Fir Plantation in 4 years:A year after fertilization, traditional fertilization could significantly promote the growth of the height and DBH of Chinese Fir,and tree height were 5.72% and 3.34% higher than CK treatment respectively,DBH were 5.62% and 4.23% higher than CK treatment respectively, the treatment that has 10 holes and fertilization depth of 15cm have best effect of accumulation growth,and it was 19.53% higher than the CK treatment.Two years after fertilization,the bag-controlled fertilization that has 6 holes and 25cm fertilization depth in the promotion of tree height and DBH growth had the best effect, higher than the CK treatment 74.15% and 84.33% respectively,and accumulation growth of the treatment that has 8 holes and 25cm fertilization depth was the biggest, higher than the CK treatment 55.52%. After three years of fertilization, the tree height of the treatment that has 8 holes and 25cm fertilization depth has the biggest increment,higher than the CK treatment 47.91%. The 6K-25 has the biggest increment of DBH and accumulation growth,higher than the CK treatment43.03% and 31.67% respectively.Ⅱ The effects on Chinese fir leaves nutrient content of fertilization Fertilization reduced the content of nitrogen, phosphorus, potassium, calcium and magnesium in Chinese fir needles.After one years of fertilization,the traditional treatment which has the 25cm fertilization depth had the highest nutrient content of the needles,and the contents of total nitrogen, total phosphorus, total potassium, calcium and magnesium in the leaves of Chinese fir was 21.40、 1.74、 10.45、 9.77、 3.82g/kg respectively.Two years after fertilization,the treatment that has 8 holes and 25cm fertilization depth had the highest nutrient content of the needles, and the content of nitrogen, phosphorus, potassium, calcium and magnesium in Chinese fir needles decreased 41.60%、29.44%、7.58%、8.25% and 10.60% respectively compared with CK treatment.Three years after fertilization,the treatment that has 6 holes and 25cm fertilization depth had the highest nutrient content of the needles, and the content of nitrogen, phosphorus, potassium, calcium and magnesium in Chinese fir needles decreased 44.45%、13.83%、 8.91%、12.26% and 16.27% respectively compared with CK treatment.III The effects on soil physical property of fertilization The change of soil natural moisture content is not large,contrast with CK treatment,The changes of fertilization treatments were not significant, which showed that the effect of Fertilization on soil natural water content was not obvious.The soil total porosity and capillary porosity showed a tendency to decrease with the growth of forest,and the soil non-capillary porosity had increased,the bag-controlled treatment which has 10 holes and 25cm fertilization depth had the best effect on reducing the soil porosity and capillary porosity.Soil bulk density showed an increasing trend, but compared with CK treatment, the effect of different fertilization treatments on soil bulk density was not significant.IV The effects on soil chemical property of fertilization(1) The effects on soil pH value and the content of soil organic matter of fertilizationFertilization increased the pH value and organic matter content of the soil, and the effect on the upper layer soil was higher than that of the lower layer soil.The upper layer soil,fertilization a year later in 2012 the pH value in the bag-controlled treatment which has 6 holes and 25cm fertilization depth was the highest,reaching 4.59,the content of organic matter in the bag-controlled treatment which has 8 holes and 25cm fertilization depth was the highest, reaching 34.41g/kg.In 2013, pH in the bag-controlled fertilizer treatment which has 6 holes and 25cm fertilization depth was the highest, reaching 4.62,the organic matter in the traditional furrow and depth of 15cm treatment was the highest, reaching 37.08g/kg.In 2014, pH in the bag-controlled fertilizer treatment which has 6 holes and 15cm fertilization depth was the highest, reaching 4.70,the organic matter in the bag-controlled fertilizer treatment which has 8 holes and 25cm fertilization depth was the highest, reaching 37.77g/kg.The lower layer soil, pH in 2012,2013, in 6 Hole 15cm fertilization treatment and 6 Hole 25cm fertilization treatment had the highest value, respectively,and fertilization basically had no effect on soil pH in 2014. The content of organic matter in 2012,2013,2014,in 6 holes 25cm treatment,10 holes 25cm treatment and 6 holes 25cm treatment content is the highest respectively.(2) The effects on soil nitrogen, phosphorus and potassium of fertilization Fertilization could obviously promote the soil total nitrogen, total phosphorus, total potassium, alkali solution nitrogen, phosphorus and potassium (soil available phosphorus content is constant, this paper does not discuss) nutrient content increased and show obvious regularity.In 2012, a year after fertilization, the soil nutrient content of the traditional furrow fertilization treatment was higher than that of the bag-controlled fertilizer treatment.In 2013 and 2014, the treatment of bag-controlled fertilizer showed obvious advantages, and the total nitrogen, total phosphorus, total phosphorus, total phosphorus, total phosphorus, total potassium, alkali solution nitrogen and available potassium in the treatment of 6 Hole 25cm were the highest.(3) The effects on soil calcium and magnesium of fertilization Fertilization could significantly improve the content of exchangeable calcium and magnesium ions in soil, and the trend of the change were similar to the change of soil total nitrogen, total phosphorus, total phosphorus, total potassium, alkali solution nitrogen and available potassium.In the first year of fertilization, the effect of traditional furrow fertilization is better than that of bag-controlled fertilizer application,too.But in 2013 and 2014, the effect of bag controlled fertilizer had begun and were s superior to the traditional fertilization treatment. In general, the content of soil exchange calcium and magnesium ions in 6 holes 25cm treatment were highest. |
PDF Full Text Request