有机肥和钾对防治大麦氨害的作用

本文主要研究粉砂性低钾土壤上尿素产生的氨对大麦的毒害以及施用有机肥和钾肥对防治大麦氨害的作用。结果表明,亩施8.13公斤尿素10天后可使土壤pH升高1.3个单位左右,氨浓度达到5.3ppm;当土壤氨浓度达到4ppm左右时,大麦产生明显的毒害,根系生长受到严重影响;根系浸出液的相对电导值和K⁺渗出比显著增高;地上部分生长也受到严重抑制,光合电子传递速率虽增高,但光合磷酸化效率却显著降低,表明氨是光合磷酸化作用的解偶联剂;氨害也抑制了硝酸还原酶的形成,体内精氨酸含量明显增高,且有脯氨酸出现。钾对防治大麦氨害有一定作用,但有机肥料的效果更加显著,采用有机肥与无机肥配合施用,既能解决大麦氨害,又能获得高产。

EFFECT OF ORGANIC MANURE AND POTASSIUM ON PREVENTING BARLEY FROM NH3 TOXICITY

This paper deals with the mechanism of inftibition of NHe from urea hydrolysis in silt loam soil with low K content and the prevention of this toxicity by the application of farm manure and K on barley (Hordeum vulgare Jess). The results obtained are summarzed as follows: The pH of soil relating to the concentration of free NH₃ raised about 1.3 units 10 days ofter applying 122kg/ha urea in the soil, and a significant inhibition of NH₃ on barley growth was observed while the concentration of free NH₃ in soil solution was about 4 ppm. The membrave structure of both root and leaf tissue was severely injured by NH₃. The injured barley was low in respiratory rate and activities of photophosphorylation, nitrate reductase and Qlutamine synthetase, but high in the rate of photosynthetic electron transport and the contents of free amino acids.