摘要
摘要:红壤性水稻土磷素易受铁、铝等固定而有效性低，过量施用磷肥则产生磷素淋失风险，研究不同供磷水平下黄泥田生产力、磷库平衡及磷组分特征，可为磷素高效管理提供依据。本研究基于福建黄泥田连续30年的供磷定位试验，研究连续30年3个供磷水平下[不施磷肥（CK）、30 kg（P₂O₅）·hm^-2（P1）、60 kg（P₂O₅）·hm^-2（P2）]水稻（1987—2004年为双季稻，2005年始种植单季稻）产量演变规律，并于试验的第31年分析土壤有效磷、全磷、无机磷库与有机磷库组分变化。结果表明，连续30年施用磷肥，与CK相比，早稻、晚稻与单季稻历年平均产量P1处理分别提高64.9%、37.0%与19.9%，P2处理分别提高67.0%、41.2%与20.4%，差异均显著。不同稻作制度下黄泥田磷肥的增产效果为早稻>晚稻>单季稻。与P1处理相比，P2处理第31年土壤有效磷含量提高190.5%，全磷含量提高32.4%，差异均显著；Al-P、Fe-P、Ca-P含量与无机磷含量均显著提高，Al-P、Fe-P占无机磷比重分别提高2.12个百分点与4.40个百分点，但O-P比重降低9.45个百分点，差异均显著。施磷肥总体提高了活性有机磷（LOP）与中等活性有机磷（MLOP）含量，降低了高稳定性有机磷（HSOP）含量，P2处理表现尤为明显；增施磷肥，LOP与MLOP占有机磷比重增加，HSOP比重降低。籽粒或秸秆产量与Al-P、Fe-P、Ca-P、MLOP、LOP含量呈显著正相关。综上，黄泥田连续30年施磷肥增产效果明显，P1与P2处理的产量无显著差异，但P1处理呈现磷表观亏缺。增施磷肥提高了无机磷Al-P、Fe-P、Ca-P比重，有机磷组分呈现由活性较低的形态向活性较高的形态转化趋势。每茬60 kg（P₂O₅）·hm^-2可维持磷素养分表观平衡并保持适宜的有效磷水平。
关键词:长期施磷肥/
黄泥田/
水稻/
土壤磷组分/
磷平衡/
产量
Abstract:Phosphorus (P) in red paddy soil is easily fixed by iron and aluminum, resulting in low P availability. Excessive phosphate fertilizer applications increase the risk of P leaching. The soil productivity, P pool balance, and characteristics of the P fractions at different levels of phosphate supply were studied in order to provide a basis for the efficient management of P in paddy fields across southern China. The study was based on a 30-year experiment in Fujian yellow-mud paddy fields. The experiment consisted of three P supply treatments in each season: control with no phosphate fertilizer (CK), 30 kg·hm^-2 P₂O₅ (P1), and 60 kg·hm^-2 P₂O₅ (P2). Double-cropping rice was planted from 1987 to 2004, and single-cropping rice was planted from 2005 onwards. The rice yields and P fractions changes under different P supply treatments over 30 consecutive years were studied. The results showed that the average grain yields of the early-season rice, late-season rice, and single-cropping rice significantly increased by 64.9%, 37.0%, and 19.9% in P1 treatment, and 67.0%, 41.2%, and 20.4% in P2 treatment, respectively. Early rice showed the highest increase in yield, followed by late rice and single-cropping rice. Under P2 treatments, in the 31^st year, the soil available P and total P contents in P2 treatment significantly increased by 190.5% and 32.4%, respectively, compared to P1 treatment. The Al-P, Fe-P, Ca-P, and total inorganic P contents also significantly increased, and the Al-P, and Fe-P fraction proportions significantly improved by 2.12 and 4.40 percentage points, respectively. However, the O-P fraction proportion significantly decreased by 9.45 percent points. Phosphate fertilizer applications generally increased the labile organic P (LOP) and medium labile organic phosphorus (MLOP) contents, but decreased the highly stable organic phosphorus (HSOP) content, especially in P2 treatment. Increasing the phosphate fertilizer application rate led to a rise in the proportion of LOP and MLOP to organic P, but it reduced the proportion of HSOP to organic P. Rice grain or straw yields were significantly positively correlated with Al-P, Fe-P, Ca-P, MLOP, and LOP contents. In conclusion, continuous applications of phosphate fertilizer significantly increased the grain yield in yellow-mud paddy soil over 30 consecutive years, but there was no significant difference in the grain yield between P1 and P2 treatments. However, apparent P deficiency was observed in P1 treatment. Increasing phosphate application rate led to a rise in the Al-P, Fe-P, and Ca-P proportions. The results showed that organic P fractions with lower activity changed into fractions with higher activity as the phosphate fertilizer application rate increased. The application of 60 kg(P₂O₅)·hm^-2 phosphate fertilizer per cropping season achieved the optimum apparent balance among P nutrients and maintained an appropriate level of available P.
Key words:Long-term P fertilization/
Yellow-mud paddy field/
Rice/
Soil phosphorus fraction/
Phosphorus balance/
Yield



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