The Research On Soil Fertility Space Heterogeneity With Eucalyptus Dunnii Plantation In The Northern Of Fujian Province

Soil characteristics have variability in the spatial distribution.Since the1970s, the research onthe soil fertility space changeability has caused the attention gradually. This concept will beintroduced in the soil fertility domain gradually, and will be a hot research spot in the soil science.This article selects the Tantou Town as the study region in Fujian province, to compare the spatialdistribution rule of soil fertility in the different soil layers. They had reflected the small region'ssoil fertility condition objecttively, to discuss the soil fertility space variation rule and the contentchanging of eucalyptus dunnii planted forest. Provide the practical theory for building theeucalyptus dunnii planted for effectively.Among the4kinds of main soil nutrient target, presenting unceasingly the declining trend;the variation of organic matter, effective N, P, K were less than75%, the space mutation aremedium variations. In the selection of sampling soil, the average content of organic matter contentin0-20cm,20-40cm,40-60cm soil layer were29.969g/kg,26.54g/kg,25.35g/kg, continue todecline. The average content of effective N were0.7055g/kg,0.5717g/kg,0.562g/kg, continue todecline. The average content of effective P were0.021g/kg,0.0216g/kg,0.02g/kg, the changingtrend of the content is not significant, the coefficient of variation is the medium variationrespectively. The average content of effective K+were0.622g/kg,0.6654g/kg,0.6418g/kg,thechanging contents present the trend first increased and then drop.In the selection of5kinds of effectiveness of metal ions, the effective Ca²⁺, effective Mn²⁺,effective Cu²⁺, effective Zn²⁺resourse of space mutation in0-20cm are medium variations,effective Ca²⁺in40-60cm level, effective Mg²⁺and effective Zn²⁺in0-20cm are strongvariation,effective Ca²⁺sample data are not accord with normal distribution, continue to rise, thisand four soil nutrient index is not consistent, metal elements that effectiveness and into soilorganic has close relationship, mutation characteristics in different hierarchy is not uniform; soilsample data Mg²⁺are not accord with normal distribution, the trend continue to rise after the firstdrop,the changing trend is not significant; effective Mn²⁺sample data do not conform to thenormal distribution, presenting content increases continually, the changing trend is not significant;effective Cu²⁺content has continued to decline, the changing trend is not significant; effectiveZn²⁺content continue to decline,the changing trend is not significant. Semivariance analysis is the core of geostatistics. The effect that using indes model fitting isgood in0-20cm,20-40cm soil layer.The effect that using spherical model fitting is good in40-60cm. The sampling spacing changing are more than30m,indicate that30m sampling space twas not accurate in reflecting the regional space mutation law of organic matter; piece of basemore than75%, explain the spatial correlation is weaker, the chemical fertilizers, by burnedmountain, random factors is stronger, such as soil organic, climate, precipitation and other naturalstructural factors, prompted the soil fertility space structure tend to uniformity, this also is manyare artificially factors of the common characteristics of strong area. The fitting effect that usingspherical model of effective N is better in0-20cm soil layer, the fitting effect that using the linearmodel is good in20-40cm,40-60cm soil layer, the linear model illustrate that the two soil layerswere entirely influenced by random factors, the reasons need further research; the changingprocesses is less than30m sampling spacing in0-20cm,30m sampling space that can accuratelyreflect the effective N in this level space variation patterns, the changing processes are more than30m sampling spacing in20-40cm,40-60cm,30m sampling space that was not accurate inreflecting the regional space mutation law of organic matter; the0-20cm more than75%, explainthat the spatial correlation is weak, the next two layer was entirely influenced by random factors.effective P on two layers using index model fitting effect is better, the use of spherical modelunder level fitting effect is better; change processes were less than30m sampling spacing,30msampling space that can accurately reflect the regional space mutation law of organic matter; pieceof base more than75%, explain the spatial correlation is weaker, the random factors influence bythe strong. fitting the effect that using gaussian model of effective K in0-20cm is better, the effectthat using spherecal model in20-40cm is good; change processes fluctuation two layers were lessthan30m sampling spacing of organic matter,30m sampling space that can accurately reflect theregional of space variation patterns and the20-40cm, more than30m sampling spacing; piece ofbase more than75%40-60cm, the spatial correlation that is weak, the less than75%, but morethan25%, explain the spatial correlation with medium.Effectiveness of the metalion semiwariance function analysis results and the main nutrientelement analysis results do not accord. The effectiveness of the20-40cm layer Ca²⁺using thegaussian model fitting effect is better, the40-60cm level respectively with ball model, the indexmodel fi tting effect is good; change of the process are more than30m sampling spacing,30m sampling space that was not accurate in reflecting the Ca2²⁺space regional validity variationpatterns, less th an30m sampling20-40cm distance; piece of base more than75%, explain thespatial correlation is weak, the20-40cm level is0, the reason to be further analysis, the level lessthan75%, explain the20-40cm space between autocorrelation. Three layers has obvious spatialnonstationarity phenomenon. Effectiveness of the Mg2²⁺by using the linear model fitting effect isbetter in0-20cm, explain the influence of random factors was strong, below the level usingspherical model fitting effect is good; change processes were less than30m sampling spacing,30m sampling space that can accurately reflect the regional validity of space mutation Mg2²⁺rules;piece of base than40-60cm level less than75%, explain the spatial correlation is weak, the0-20cm piece of base than for0,0-20cm layer shows the effectiveness of the Mg2²⁺was entirely theinfluence of random effects. Effective Mn2²⁺the use of gaussian model fitting effect is better, theuse of spherical20-40cm model fitting effect is good;change processes were less than30msampling spacing,30m sampling space that can accurately reflect the Mn2²⁺space area effectivelyvariation patterns; piece of base more than75%, explain the spatial correlation weakly. EffectiveCu2²⁺fluctuation two layers use index model fitting effect is good, and the20-40cm level usingspherical model fitting effect is good; more than30m the change process of sampling spacing,30m sampling space that was not accurate in reflecting the level of effective Cu2²⁺space variationpatterns,20-40cm and last level less than30m sampling spacing; Piece of base more than75%,explain the spatial correlation weakly. Effective Zn2²⁺use index model fitting effect is better;Become40-60cm by more than30m process of sampling spacing,30m sampling space that wasnot accurate in reflecting the area of effect Zn2²⁺space variation patterns, the less than30msampling spacing; Piece of base more than75%, explain the spatial correlation weakly.According to the analysis result of semiwariance,30m sampling spacing between theelements is not accurate in reflecting the elements of space variation patterns, such as effective Nin0-20cm, effective P and effective Mg2²⁺in0-20cm,20-40cm,40-60cm,effective K in0-20cm,40-60cm, effective Mg2²⁺in20-40cm,40-60cm and effective Ca2²⁺in20-40cm, effectiveZn2²⁺and effective Ca2²⁺in20-40cm and0-20cm.30m sampling span not applicable55%, suggeststhe need for expanding sampling spacing.The kriging interpolation space graph of organic matter shows: in0-20cm,20-40cm,40-60cm soil layer, content than the32.7g/kg regional focus on sampling in western and central areas of the west area. These regional content is higher because of these areas may be littlegradient, part for the valley, using of organic matter concentration; content is less than32.7g/kgarea and its large slope, soil and water loss, there are certain relationship.Effective N in0-20cm,20-40cm,40-60cm soil sampling concentration do not accord. The0-20cm concentrationdistribution in northwest and southwest,20-40cm distribution is m ore uniform, without obviousconcentration, mainly concentrated in the central area, this aspect elucidation effective N a strongspatial heterogeneity, but specific reasons to be further dis cussed. Effective P content than the0.02g/kg area on the top of the focus on the northwest sampling, cen tral south area, thedistribution of the20-40cm is consistent, explain and phosphorus in the space di stribution ofrelative stability, of the soil layer in dissociation are relatively weak. Effective K con tent than the0.77g/kg area0-20cm focused on the west and the southeast, sampling area in the mid dle a focuson southwest, central China, southeast, present three pointlike area in the0-20cm, focu sed on thesouthwest and the central, and the southeast, three layer has certain stability.Metal elements into soil and effectiveness PSD have a close relationship. Effective Ca2²⁺content than the0.141g/kg area mainly focus on the top of the central south area,20-40cm of thenorthwest, present a single pointlike distribution, the overall less content, and the40-60cm in thesouth and south east area, three layer distribution is not the same. Effective Mg2²⁺content largeregion mainly the southeastern part of the40-60cm level, present a single pointlike distribution,the overall content is less, the more common, without obvious concentration distribution, threelayer distribution is not the same. Effective Mn2²⁺content than the20.072g/kg area mainly focuson the southwest of low er level on regional; three layers are consistent with the distribution.Effective Cu2²⁺content than the0.270g/kg area mainly focus on the central part of the40-60cmlevel on regional, three layer distr ibution relatively consistent,0-20cm distribution rather morescattered. Effective Zn2²⁺content a large area mainly focus on the top of the western region, the20-40cm of the western and central, the west and southeast area, three layer is consistent with thedistribution. Three layer distribution of the consistency of the differences, probably with specificelements of the activity and the decom position of organic soil forming process and so on manykinds of factors, and the specific problem should also be specific analysis.