耕作年限对棉田土壤颗粒及矿物结合态有机碳的影响

Effects of Cultivation Years on Particulate Organic Carbon and Mineral-Associated Organic Carbon in Cotton Soil

研究耕作年限对棉田土壤颗粒及矿物结合态有机碳的影响。以相应荒地为对照,选取南北疆兰州湾、31团和普惠农场3个典型绿洲不同耕作年限土壤为研究对象,应用物理分组方法研究颗粒及矿物结合态有机碳的变化规律。结果表明:耕作有利于棉田土壤总有机碳的积累,耕作(0～5年)总有机碳增加迅速,年均增加在0.65g/kg以上;颗粒有机物、有机碳和颗粒有机碳的分配比例在耕作0～10年间增加,较荒地分别增加50.12%,263.64%,79.79%,10年后下降。矿物结合态有机碳含量则随耕作年限的延长递增,矿物结合态有机物含量变化趋势与颗粒有机物相反。土壤有机碳在耕作1～10年增加,有利于土壤质量的提高,是荒漠区土壤碳汇,是合理的耕作年限。

Effects of cultivation years on particulate and mineral-associated organic carbon in cotton soil were investigated.Taking corresponded wasteland as the control,and selecting three typical different cultivation years of oasis soil in the Lanzhouwan,No.31 farm and Puhui farm of southern and northern Xinjiang as the research object,and the physical fractionation method was applied to investigate the variation law of particulate and mineral-associated organic carbon.The results showed that cultivation could enhance the soil organic carbon accumulation in cotton soil,and increased rapidly in cultivation stage（from 1 year to 5 years）,annual average increasing amount was upwards 0.65 g/kg.Particulate organic matter,organic carbon and distribution of particulate organic matter were increased in cultivation from 1 year to 10 years and declined after 10 years.Compared with wasteland,they were increased by 50.12%,263.64% and 9.79%,respectively.Mineral-associated organic carbon increased with increasing cultivation,the changes of mineral-associated organic matter was opposite to particulate organic matter.Soil organic carbon contents were increased from 1 year to 10 years when it was a reasonable cultivation stage,and the cultivation was beneficial to enhance the soil quality,and it was the soil carbon pool in arid and desert region.