秸秆还田对土壤脱氢酶和多酚氧化酶活性动态变化的影响

Effect of matching use of straw and fertilizer on the dynamic changes of soil dehydrogenase and polyphenoloxidase activities

通过旱田试验研究了冬小麦生长期内,秸秆还田与肥料配施对土壤脱氢酶活性和多酚氧化酶活性动态变化的影响。结果表明,土壤脱氢酶活性在冬小麦生长期内波动较大,出现多个峰值;秸秆还田和厩肥的施入均能显著提高土壤脱氢酶活性。在冬小麦生长后期,尿素能显著提高土壤脱氢酶活性,而过磷酸钙的施入一定程度上降低了土壤脱氢酶活性。土壤多酚氧化酶活性表现为在冬小麦生长前期和中期活性较低,4、5月份活性迅速升高,出现高峰值,随后在收获期迅速降低;秸秆还田和过磷酸钙对土壤多酚氧化酶活性的影响不显著。在冬小麦生长中期,厩肥和尿素对土壤多酚氧化酶活性有一定的抑制作用,在冬小麦生长旺盛期,厩肥和尿素对多酚氧化酶活性的抑制作用不明显。

Soil enzyme activities play an important role in the material cycle and energy flow of ecosystem. The objective of this field experiment was to determine the effect of the use of organic and chemical fertilizers on the dynamic changes of soil dehydrogenase and polyphenoloxidase activities in growth stages of winter wheat. The experiment included five fertilizer treatments： control （no fertilizer） ; returning corn straw to field; returning corn straw to field combining ap- plication of manure; returning corn straw to field combining application of nitrogen fertilizer （pure N210 kg/hm^2） ; and returning corn straw to field combining application of nitrogen （pure N 210 kg/hm^2） and phosphate fertilizers （P205 150 kg/hm^2）. Each treatment was replicated four times. The results showed that the fluctuation of the trend of dynamic changes of soil dehydro genase activity was much stronger than that of polyphenoloxidase activity. Manure application and returning corn straw to field could increase significantly the dehydrogenase activity. In the late growth stage of winter wheat, nitrogen fertilizer application could increase significantly the dehydrogenase activity, but the increasing action was weakened by the input of phosphate fertilizer. The effect of phosphate fertilizer application and returning corn straw to field on the soil polyphenoloxidase activity did not reach the significant level. In the middle growth stage of winter wheat, manure and nitrogen fertilizer application could restrain the polyphenoloxidase activity in this experiment. But in late stages, especially in April and May, the restraining action became weaker.