Abstract: In order to find a suitable fertilization mode for low-fertility paddy soil, single application of chemical fertilizer ( NPK) was used as control, and the effects of long-term ( 8 years) different fertilization measures[chemical fertilizer combined with straw added straw fast-rot fungus (NPK+RS), controlled-release BB fertilizer combined with cow manure ( BBF+CM)] on aggregate composition,stability and nutrient distribution characteristics in yellow clayey paddy soil were studied.The results showed that compared with the soil nutrient conditions at the beginning of the experiment, the three fertilization treatments generally increased the soil organic matter,total nitrogen and available phosphorus contents in the cultivated layer,the most obvious effect was observed in the BBF +CM treatment,soil organic matter,total nitrogen and available phosphorus contents significantly increased by 41%,49% and 55% respectively. Compared with NPK treatment, NPK+RS and BBF+CM treatments increased the proportion of aggregates>2.00 mm in particle size and mean weight diameter( MWD) and geometric mean diameter(GMD),the improvement of BBF+CM treatment was slightly higher than that of NPK+RS treatment.In the three fertilization treatments, the rice rhizosphere soil aggregates MWD and GMD gradually increased with the progress of the rice growth period,while the non-rhizosphere soil aggregates MWD and GMD were generally the largest at the rice tillering stage and the smallest at the rice jointing stage.At the rice tillering stage, the non-rhizosphere soil aggregates MWD and GMD of the three fertilization treatments were larger than the rhizosphere soil;at the rice jointing stage and mature stage,the results were reversed. The results of variance analysis showed that rice sampling time, fertilization treatment and their interactions were the main factors affecting the stability of aggregates in yellow clayey paddy soil. The correlation analysis results showed that the stability of soil aggregates had significantly positive correlation with the content of soil organic matter,and significantly negative correlation with the content of available potassium. There were differences in the nutrient distribution of aggregates with different particle sizes. The organic matter and total nitrogen contents of>2.00 mm aggregates were higher,while the contents of available phosphorus and available potassium of<0.25 mm and 0.25—2.00 mm aggregates were higher. Compared with NPK treatment,NPK+RS and BBF+CM treatments could significantly increase the organic matter, total nitrogen, available phosphorus and available potassium contents of different sizes of aggregates.The organic matter, total nitrogen, available phosphorus and available potassium contents of different sizes of aggregates of NPK+RS treatment increased by 19%—23%,19%—29%, 26%—49% and 131%—157% respectively, and those of BBF+CM treatment increased by 23%—34%, 28%—81%, 47%—178% and 17%—41% respectively.In summary, both BBF+CM and NPK+RS fertilization modes could increase soil nutrient content,and improve soil structure in yellow clayey paddy. Among them,BBF+CM mode showed a larger positive effect,and could be used as an effective measure to improve soil productivity in low-yield yellow clayey paddy soil.

Key words: Fertilization measures, Straw, Cow manure, Yellow clayey paddy soil, Aggregate composition, Aggregate stability, Nutrient distribution, Mean weight diameter(MWD), Geometric mean diameter(GMD)

摘要： 为了找出适合低肥力黄泥田的培肥模式，以单施化肥（NPK）处理为对照，研究长期（8 a）不同培肥措施［化肥配施秸秆同时添加秸秆快腐菌剂（NPK+RS）、控释BB肥配施牛粪（BBF+CM）］下黄泥田水稻土团聚体组成、稳定性及养分分布特征。结果表明，与试验开始时土壤养分状况相比，3种施肥处理总体上均提高了耕层土壤有机质、全氮、有效磷含量，其中，BBF+CM处理有机质、全氮、有效磷含量分别显著提高了41%、49%、55%，提升效果最明显。与NPK处理相比，NPK+RS和BBF+CM处理提高了＞2.00 mm粒径团聚体所占比例及平均质量直径(MWD)、几何平均直径(GMD)，提升幅度BBF+CM处理稍高于NPK+RS处理。3个施肥处理水稻根际土壤团聚体MWD和GMD均随着水稻生育时期的推进逐渐增大，而非根际土壤团聚体MWD和GMD总体上在水稻分蘖期最大、拔节期最小。在水稻分蘖期，3个施肥处理非根际土壤团聚体MWD和GMD大于根际土壤，在水稻拔节期和成熟期，结果反之。方差分析结果表明，水稻取样时间、施肥处理及其互作是影响黄泥田水稻土团聚体稳定性的主要因子。相关性分析结果表明，土壤团聚体稳定性与土壤有机质、速效钾含量分别具有极显著正、负相关关系。不同粒径团聚体养分分布存在差异，其中＞2.00 mm粒径团聚体有机质和全氮含量较高，而＜0.25 mm和0.25~2.00 mm 团聚体有效磷、速效钾含量较高。与NPK处理相比，NPK+RS和BBF+CM处理总体上均可以显著提高各级粒径团聚体有机质、全氮、有效磷、速效钾含量，其中，NPK+RS处理各粒径团聚体有机质含量提高19%～23%，全氮含量提高19%～29%，有效磷含量提高26%～49%，速效钾含量提高131%～157%；而BBF+CM处理各粒径团聚体有机质含量提高23%～34%，全氮含量提高28%～81%，有效磷含量提高47%～178%，速效钾含量提高17%～41%。综上所述，BBF+CM和NPK+RS 2种施肥模式均能提升黄泥田土壤养分含量、改善土壤结构，其中BBF+CM处理效果较优，可以作为低产黄泥田土壤生产力提升的有效措施。

关键词: 施肥措施；秸秆；牛粪；黄泥田水稻土；团聚体组成；团聚体稳定性；养分分布；平均质量直径（MWD）, 几何平均直径（GMD）