关于土壤氮素矿化势作为有效氮指标的研究

以2种作物,12个质地、有机质、全氮及碳氮比不同的土壤进行的盆栽和培养试验表明,利用土壤氮素矿化势计算得出作物生长期间的矿化氮量与作物吸收氮量有密切关系,且两者间有稳定比值。根据土壤氮素矿化势计算作物生长期间可利用的氮素有较为合理的依据,值得重视。用KCl煮沸法所浸取的氮素与短期培养所矿化的氮素是高度正相关,且回归系数接近1,说明二者在表示土壤供氮能力方面有同样价值。

STUDY ON SOIL NITROCEN MINERALIZATION POTENTIAL AS AN INDEX OF SOIL NITROGEN AVAILABILITY

A pot and a short-term incubation experiments carried out with 12 soils covering a range of texture, organic matter, to'tal nitrogen contents and C: N ratios show that plant uptake N was very well correlated with either N mineralized after a 2-week incubation or N mineralized during plant growth periods with stable ratios, which was calculated from soil N mineralization potentials. And it is worth noticing that the Stable ratios of mineralized N estimated during plant growth periods to plant uptake N were found both for barley and for ryegrass. Also the N mi-neralized after a 2 -week incubation was highly correlated with N extracted by KCl, and the regression coefficient was apporoxi matively to 1 Both the short-term incubation and KCl methods provide a reasonable estimation of the nitrogen supplying capacities of soils.