Studies On Relationship Between Soil Spatial Variability And Crop Optimal Disposition In Northwest Plateau Of Hebei Based On GIS

The topography is undulation in northwest plateau of hebei,the existence spatial variability of soil physics and chemistry character,to further raise the land capability,must scientific understand each principal of soil characteristic in the spatial variation,by the optimal layout crops.This project in the predecessor studies in the foundation,the utilization geographic information system(GIS)and the geostatistic method,had analyzed on the Hebei northwest plateau under the undulation plateau landform the small basin farmland soil fertility factor and the quality of material spatial changeability,had discussed the elevation,the slope,the slope to and so on terrain factors and the soil each physics and chemistry character distributed correlational dependence,based on this and unified the field to estimate production the data to study the type area the land utilization to carry on the experimental plan,carried on the soil protection and the crop disposition reasonably for the region has provided the theory and the technical basis.The main findings were as follows:1.the studied on the research area soil fertility factor and the quality of material had carried on the traditional statistical analysis,compared with the nation second general detailed soil survey's nutrient grading standards result indicated that the sampling area main fertility factor density concentrated much in medium and lacks level;The AP content was lower,the type area soil was more barren.The OM,TN,AP and AK four manure strength factor's coefficient of variation was the medium intensity.The sampling area soil texture total body surface appears in the 0～40cm scope along with the soil layer deepening, but the thinning,preserves moisture and fertility the nature to strengthen gradually.the 0～60cm various soil layers physical property clay content's coefficient of variation was also the medium intensity,but increased gradually along with the soil layer deepening coefficient of variation.The quality of material condition traditional statistical result which and the physical property clay proportion condition attributes by the fractal dimension were close.2.the research had been show about the research area soil fertility factor and the quality of material spatial variation characteristic.Used the geostatistic method analysis to indicate that the research area OM,TN and AP's theoretical model very good conforms to the exponential model,the AK very good conforms to the spherical model,the residual value was small.Four kind of soil fertility factor except AP for medium spatial autocorrelation,and with elevation relevance bad,other had the intense spatial autocorrelation and with the elevation existence very strong inverse correlation relations, reaches the extremely remarkable level.Four and slope and slope to the relevance was very small,and was not remarkable,the range scope was bigger than the sample spacing.Identical soil layer,besides particle size 2～1 mm broken stones,other various grades soil particle spatial distribution with elevation existence strong correlational dependence, and reacheed the extremely remarkable level.The different soil layer,the identical particle size pellet along with the soil layer deepening,it changes with the elevation change's correlation coefficient absolute value was small,relevant variation.In the soil various particle sizes broken stone's spatial distribution and the slope and the slope approach the relevance was very small,and was not remarkable.The physical property clay content, very good conforms to the exponential model besides the 0～10 cm soil layer's theoretical model,other each very good conforms to the spherical model,residual value close zero. Eliminated 20～30,30～40 cm two was the medium degree,other each had the intense spatial autocorrelation.Various soil layers' range increases and was bigger than the sample spacing gradually along with the soil layer deepening.The physical property clay content change and reaches the extremely remarkable level with the elevation existence big inverse correlation relations,the same slope and the slope approach the relevance was very small. The soil fractal dimension's spatial variation was also similar with the soil physical property day's situation.3.To study the area crop distribution and the plan disposition analysis indicated that in 21.99 hm2 type area total cultivated area,the current planter's beet,the naked oat,the potato,reached the proportion which occupies with the corn and the red kidney bean five crops respectively was 32.93%,36.88%,5.39%,5.61%and 19.19%;Choosed the region symbolic soil fertility target 0～10 cm surface layer soil the physical property clay content to carry on the farmland regionalization altogether to divide into 4 levels:The 1st level, soil physical property clay content＞30%;The 2nd level,25～30%;The 3rd level,20～25%; The 4th level,＜20%.,Showed that the plots 1～4 the proportion of cultivated land were 3.32 percent and 26.39 percent,32.16 percent and 38.13 percent.Beet,naked oats and forage maize crop yield with the sea level rise,decline in arable land fertility,reducing output.Red kidney beans and potatoes of the highest yield in two of arable land,and by 1, 3 and 4 were lower.Comparative studies of crop around the allocation of plots of the total net income,showed that the fitness of crops suitable for large-scale production with 48.54 percent of the synergistic potential.