水稻土有机-无机肥料配合施用的效应(之五)

本文旨在研究不同施肥结构对红壤性稻田土壤有机质性质及其在土壤肥力中的作用的影响.结果表明:与单施化肥和无肥处理比较,有机肥与化肥配合施用不仅有利于土壤有机质的积累,而且其品质也有明显改善,主要表现在易氧化有机质、胡/富比、土壤有机无机复合量及松结态有机质的数量明显提高.有机质状况的改善,提高了土壤氮素贮量,活化了土壤氮素,明显增加了土壤酸解氮总量,其中,氨基酸态氮和未鉴定态氮增加尤为明显,同时还促进了土壤结构的形成,改善了土壤物理条件。相关分析表明:土壤有机质及其复合状况与土壤肥力呈显著正相关;有机质氧化稳定系数(Kos 值)与土壤氮素肥力、CEC、土壤有机质总量、有机无机复合量及松结态有机质含量呈显著的负相关.初步认为,有机无机复合量及有机质氧化稳定系数可作为衡量稻田土壤培肥效果和土壤有机质品质的重要参考指标.

THE EFFECT OF MIXED APPLICATION OF ORGANIC AND INORGANIC FERTILIZERS IN PADDY SOIL(The fifth report)

This paper deals with the effects of different fertilizer systems on the properties of soilorganic matter and its role in soil fertility.Experimental results showed that compared withthe treatments of no fertilizer or inorganic fertilizer only,the mixed application of organicand inorganic fertilizers not only benefited the accumulation of soil organic matter,but alsoimproved its quality,i.e,the marked increases of the content of readily oxidizable organicmatter,HA/FA,the quantity of complex organic carbon(QC),and the content of theloosely combined organic matter.When the conditions of soil organic matter were im-proved,the soil nitrogen elements were activated,and the amount of acidhydrolyzable-N(especially its amino acid-N and unidentifiedmorphology-N)was remark-ably raised.Meanwhile the structure and the physical properties of the soil were also im-proved.Correlation analyses revealed that there was a significant positive correlationbetween soil organic matter,QC and soil fertility;while notable negative interrelation be-tween the coefficient of oxidation stability of O.M.(Kos)and the soil fertility of nitrogen, CEC,the total content of O.M.,QC,and the loosely combined organic matter respectivelywas observed.Therefore,it was suggested that QC and Kos may serve as the main reference indexes of the quality of soil organic matter and the result of increasing soil fertility.