不同施肥对退化稻田土壤肥力恢复的影响

为了探明不同施肥修复措施对退化水稻土壤肥力的修复作用,自2005年起采用盆栽试验连续3年对长期缺肥退化水稻土进行了土壤肥力培肥试验研究。结果表明:6种施肥修复措施均可以显著地改善退化水稻土的肥力特征,土壤有机质含量最多提高了14.0%,土壤有效磷显著增加,最高增加量达到39.0mg.kg-1,土壤速效钾均恢复到中等水平(80mg.kg-1)以上,但土壤碱解氮除水稻专用复合肥(ZY)处理基本维持试验前水平外,其他施肥措施均有所下降;不同施肥修复措施均可明显地提高土壤微生物数量、微生物活性以及微生物生物量C、N、P含量,但以有机无机肥配合效果最佳;有机无机肥配合还可以促进稻谷产量和显著提高肥料农学效率;对于长期不施肥导致的退化稻田土壤肥力的修复以在施用水稻专用复合肥的基础上配施有机肥的效果最佳。

Effects of different fertilization on the improvement of degraded paddy soil fertility in red earth region

A 3-year pot experiment was conducted at the experimental base of College of Resources and Environment,Hunan Agricultural University to study the improvement effect of different fertilization on degraded paddy soil fertility in red earth region Since 2005.All the test six fertilization measures improved the soil fertility significantly.The soil organic matter content increased up to 14.0%,soil available P increased up to 39.0 mg·kg~(-1),soil available K recovered to medium level(80 mg·kg~(-1)),but soil available N decreased except that it was maintained at the level before experiment in rice-specific fertilizer treatment.All fertilization treatments increased the soil microbes'amount,soil microbial activity,and soil microbial biomass C,N and P,with the best effect in treatment inorganic fertilizers incorporating with organic manure.The combined application of chemical fertilizers and organic manure also increased the rice grain yield and fertilizer agricultural use efficiency.It Was suggested that applying rice-specific fertilizer in combining with organic manure could have the best improvement effect for the degraded paddy soil fertility resulted by long term non-fertilization.