| In the oasis farmland of Xinjiang,due to unreasonable irrigation,fertilization,reclamation and salinization,soil "barren patches" of small crops of varying size were gradually formed,The "barren patches"are salt efflorescence and seriously inhibited crop growth in Oasis farmland.These "barren patches" resulted in the reduction of effective cultivated land.Grain and cotton output decreased and economic benefits decreased.In this paper,37 soil "barren patches" were selected in oasis farmland of Manas County by remote sensing images,through Landsat 8 satellite images and visual interpretation of UAV.The variation characteristics of organic matter,alkali-hydrolyzed nitrogen and available phosphorus from the "barren patches" center to the external were analyzed Thirty-seven bare spots were divided by salt content,pH value and clay content of sand powder.The effects of salinity,acidity,alkalinity and texture on organic matter,alkali-hydrolyzed nitrogen and available phosphorus in "Barren Patches" were discussed.The main results are as follows:(1)There were significant differences in the contents of organic matter,alkaline nitrogen and available phosphorus in "barren patches" center,edge and external soils in Oasis farmland,Manas County,External>center.The contents of OM、AN and AP in 0-10 cm soil layer were significantly higher than those in other soil layers at different soil depth.(2)In different salinization degrees,the average organic matter and available phosphorus content from the "barren patches" center to the external of non-salinized and slight salinized soil have no significant difference.The content of organic matter and available phosphorus in the "barren patches" external of sever salinized soil and saline soil is significantly higher than patches center.The average content of alkaline hydrolyzable nitrogen in the "barren patches" center is significantly lower than patches center.The average content of organic matter and alkali-hydrolyzable nitrogen in the "barren patches" center is lower than patches external with different acidity and alkalinity.The average content of available phosphorus from the"barren patches" center to the external has no significant difference.(3)The relationship between soil salinity,clay content,acidity and alkalinity and soil "barren patches"nutrients(OM、AN and AP)indicated that The contents of organic matter and salt in 20-30 cm soil layer were significantly correlated.Alkali-hydrolyzed nitrogen at the edge of 10-20 cm and available phosphorus at the edge of 20-30 cm were significantly correlated with ph.In other soil layers,there was no significant correlation between soil nutrients inside and outside the "Barren Patches".There was a significant correlation between the organic matter content and clay content in the patch of 0-10 cm,but no significant correlation between the soil nutrient content and clay content in other soil layers. |
