2种耕作方式下玉米还田秸秆养分释放特征研究

为了探讨不同耕作方式下玉米秸秆还田腐解规律，采用尼龙网袋法，以玉米秸秆为研究对象，大田条件下研究不同耕作模式（旋耕和深耕）还田秸秆干物质消耗、养分（N、P、K、有机质）释放特征，以及C/N比动态变化规律。结果表明，玉米秸秆在翻埋后一个月内是快速腐解期，其N、P、K及有机质碳能在较短时间内快速释放，此时期内2种耕作方式各养分损失率分别为74.6%、39.3%、78.5%、50.2%和71.8%、34.1%、66.5%、42.9%。土壤深耕+秸秆还田耕作方式有利于秸秆的快速腐解，但对最终秸秆养分的释放量没有影响。随着时间的推移，2种耕作方式下的秸秆养分剩余量趋于一致。

Study of Characteristic of Nutrient Releasing of Maize Straw with Two Tillage Methods

For exploring the rule of decompose rate of maize straw with two farming modes, the article studied dry-matter consuming, characteristic of nutrient releasing (N, P, K and organic matter) and the dynamic change rule of C/N rate of maize straw with two farming modes (rotary tillage and deep tillage) in land for growing field crops by method of nylon net bag. The result showed that: one month after maize straw turned over was the rapid decompose period, when N, P, K and C could release rapidly in short time, and the period, the lose rate of each nutrient were 74.6%, 39.3%, 78.5%, 50.2% and 71.8%, 34.1%, 66.5%, 42.9% with the two farming modes. The farming mode of deep tillage + straw turnover was beneficial to the rapid decompose of the maize straw, but had no effect on the final amount of the maize straw nutrient releasing. As the time goes on, the surplus of the crop straw nutrient under the two tillage methods tended to no difference.