Effects on carbon,nitrogen,and phosphorus cycling functional genes under straw mulching and fallow cultivation
To explore a protective tillage method based on planting and land cultivation suitable for sloped farmland,field experiments in combination with gene chip research methods were used to study the effects of straw mulching and fallow cultivation technology(including alternate year straw mulch fallow with rotary tillage(RF)and 2-year rotary tillage with annual straw mulch fallow(RRF))in comparison with conventional tillage(CRT,rotary tillage after straw removal)measures on soil carbon,nitrogen,and phosphorus cycling functional genes.The results showed that inputting exogenous C stimulated the organic matter degradation potential of soil microorganisms,whether straw mulching was performed in the previous season or the current season,and that the abundance of degradation functional genes(acsE,xylA and rbcL)involved in the soil C cycle increased to a certain extent.The average relative abundance of the xylA gene increased by 43.12%compared with that of the CRT treatment.Conventional tillage without straw return to the field significantly increased the relative abundance of the genes involved in C assimilation,such as acsA,which increased by 33.03%.After straw mulching and fallow cultivation,the abundance of the gdh gene was increased,indicating promotion of the transformation of soil N from ammonium N to nitrate N.Similarly,accumulation of active P was higher,and the abundance of the alkaline phosphatase gene phoD,which was positively correlated with that of AP and phnk genes,increased by an average of 59.57%compared with the value of CRT.The turnover capacity of soil microorganism C,N,and P was improved under straw return,and the conversion of exogenous organic carbon and accumulation of soil SOC were increased.Although there was little difference between straw mulching in the current season and that in the previous season in the short term,these results provide a scientific basis for the implementation of protective farming techniques on sloped farmland to prevent and control water and soil loss in the black soil region of northeast China.
straw returngene chipsoil element recyclingmicrobial functiontillage
万方数据
维普
