Soil Fertility Index And Fertility Quality Evaluation Of Chinese Fir And Masson Pine Plantation

Chinese fir(Cunninghamia lanceolata) and Masson pine (Pinus massoniana) plantation are main plantations in south of China. Many studies revealed that continue cropping of Chinese fir and pure Masson pine plantation would cause soil degradation and forest productivity reduction.And there are so many assumptions about soil degradation. Chinese fir plantation and Masson pine plantation soil samples were taken from Fengshushan forest farm in jingdezhen, jiangxi province to do some physical and chemical analysis in contrast with shrubland, broad-leaved forest and mixed broadleaf-conifer forest .And the right index were chosen to evaluate the soil fertility. The result as follows:(1)The physical character of Chinese fir plantation and Masson pine plantation soil is notably different from the contrast samples.The total porosity of the soil, from the Masson pine plantation and the first generation fir plantation, greatly differ from broad-leaved forest and mixed broadleaf-conifer forest;The bulk density of Masson pine plantation and the second generation fir plantation soil samlpes is notably different from the broad-leaved forest and mixed broadleaf-conifer forest ones;By generations planting, the bulk density grows, total porosity decreases and water content drops.(2)Continuous cropping Chinese fir or a long-term Masson pine plantation would reduce some fertility contents. The organic matter, total nitrogen, hydrolyzabal nitrogen and available potassium of the surface layer in the second generation fir plantation are lower than the first generation fir plantation, but the available phosphorus increased 16.36% . Compared to the contrast ones, the organic matter of the surface layer in the Chinese fir and Masson pine plantation is lower than the mixed broadleaf-conifer forest and shrubland. The total nitrogen in the Chinese fir and Masson pine plantation is higher than the contrast ones, but the available potassium is far more lower than the contrast ones. The hydrolyzabal nitrogen of the first Chinese fir plantation is higher than the contrast ones, but the opposite result in the second Chinese fir plantation. The hydrolyzabal nitrogen of Masson pine plantation is lower than the broad-leaved forest and mixed broadleaf-conifer forest. The available phosphorus of the Chinese fir and Masson pine plantation is lower than the broad-leaved forest and shrubland, and there is no remarkable difference from the broadleaf-conifer forest. In summary, the nutrient of the second Chinese fir plantation is lower than the first Chinese fir plantation, the available nutrient of the Masson pine plantation is markedly lower than the broad-leaved forest and mixed broadleaf-conifer forest.(3)The pH in artificial plantations is a little bit lower but with no big difference refer to contrast forests.No big difference can be found between the artificial plantation and the contrast forests in the exchangeable H+ and exchangeable Al3+.The second generation fir plantation is higher than first generation in the exchangeable H+ and exchangeable Al3+.As to CEC content in surface soil(0-20cm),Chinese fir plantation has no big difference with the contrast forests, but the Masson pine plantation is on the opposite.(4)Principal component analytical method is used to value the soil fertility among multivariate statistics, the result is as follows: secondary mixed broadleaf-conifer forest >first generation fir plantation > shrubland> secondary broad-leaved forest > second generation fir plantation > Masson pine plantation.