保护性耕作对喀斯特山区旱地土壤理化性质的影响

Effect of Mechanized Conservation Tillage on Soil Physicochemical Properties of Dryland in Karst Mountainous Area

为揭示保护性耕作对喀斯特山区旱地土壤理化性质的影响,以常规耕作(CGGZ)为对照,在贵州省大方县典型喀斯特山区进行连续4年的对比试验,研究机械化保护性耕作(BHGZ)对喀斯特山区旱地土壤理化性状的影响。结果表明,在0-40cm土层,2种耕作方式的土壤孔隙度、毛管持水量、有机质、全氮、碱解氮、全磷、有效磷、全钾和速效钾含量均是耕层(0-20cm)高于下层,并随耕作年限的增加,这些指标逐渐增加,但土壤容重则相反。机械化保护性耕作土壤孔隙度、毛管持水量、有机质、全氮、全磷、有效磷、全钾和速效钾含量明显高于常规耕作的土壤,而容重和碱解氮的含量则略低于常规耕作土壤。4年机械化保护性耕作的耕层土壤有机质、全氮、全磷、有效磷、全钾和速效钾含量分别比常规耕作提高6.97%,9.13%,4.16%,9.16%,2.10%和3.09%,碱解氮降低4.46%;连续4年机械化保护性耕作20-40cm土壤有机质、全氮、全磷、有效磷、全钾和速效钾的含量分别比常规耕作提高12.58%,12.70%,7.71%,13.00%,2.90%和6.60%,碱解氮降低4.96%。

To examine the influence of mechanized conservation tillage （BHGZ） on soil pnyslcocnemlcai properues of dryland, a set of experiments compared with traditional cultivated model （CGGZ） were carried out for four years at the typical Karst region of Dafang County. The Results indicated that, with except of soil bulk density, soil porosity, capillary water capacity, organic matter, total nitrogen, alkali-hydrolyzable nitrogen, total phosphorus, available phosphorus, total potassium and available potassium within 0--20 cm soil were higher than that within 20--40 cm and these properties increased with increasing time. Within 0--20 cm soil depth, the soil organic matter, total nitrogen, total phosphorus, available phosphorus, total potassium and available potas- sium under the mechanization conservation tillage were 6.97%, 9.13%, 4.16%, 9.16%, 2.10% and 3.09% higher than that under traditional cultivated model respectively, while the content of alkali-hydrolyzable ni- trogen was slightly lower about 4.46%. In the soil layers as high as 20--40 cm, the organic matter content, total nitrogen, total phosphorus, available phosphorus, total potassium and available potassium after four year successive mechanization conservation tillage increased by 12.58%, 12.70%, 7.71%, 13.00%, 2.90% and 6. 6% respectively, while the content of alkali-hydrolyzable nitrogen reduced by 4.96%.