玉米不同生长时期土壤氨基酸氮的动态特征

氨基酸在土壤氮素循环及作物养分供给中既扮演着库的角色又起着源的作用。本文通过田间试验研究肥料施用及肥料与秸秆配施后土壤氨基酸在玉米不同生长时期的数量变化,探讨了土壤氨基酸的可利用性及其动态特征。研究发现,在玉米需氮高峰期,耕层土壤,尤其是10～20 cm层次的氨基酸氮含量降低以部分满足植物的氮素需求;在玉米成熟期,土壤氨基酸含量又有所回升。秸秆配施增加了土壤氨基酸氮的含量,从而提高了土壤持续供氮能力。

Dynamic of Amino Acid N in Different Grow Seasons of Maize in Different Management

Soil amino acids are important for plant nutrition and act as both sink and source of nitrogen.In order to probe into the dynamics of soil amino acids and their availability in agricultural ecosystem,a field experiment was conducted on the two treatments included N fertilizer applications with and without crop stalk return.The contents of amino acids were determined at different growing stages of maize(Zea mays L.).During the silking and filling stages when the N uptake of the crop was intense,the contents of soil amino acids,especially in 10-20 cm depth,declined significantly to partly compensate the N demand.At the stage of harvest,the contents of soil amino acids rebounded although the magnitude in 10-20 cm was still lower than original value in N fertilization.The return of crop stalk enhanced the accumulation of soil amino acids and improved the capability of soil for the sustainable N application.