湖南省不同区域早稻施磷效应及土壤速效磷丰缺指标研究

Study on Response of Early Rice to P Application and Abundance and Deficiency Indices of Soil Available P in different Regions of Hunan Province

为研究施磷对早稻产量及经济效应的影响,并建立湖南省早稻土壤速效磷的丰缺指标,于2005—2008年在湖南省双季稻主产区按湘北、湘中—湘东及湘南3个区域共布置120个磷肥早稻田间试验。结果表明,早稻施磷具有明显的增产效果及经济效应,增产及增收效果均表现为:湘东—湘中丘陵、中低山区>湘北环洞庭湖平原、低山丘陵区>湘南中低山、丘陵区。研究还表明土壤速效磷对施磷增产效应及经济效益有显著影响,施磷增产幅度及经济回报均随土壤速效磷含量的提高而降低。早稻种植体系中,湘北区土壤速效磷"低"、"中"、"高"丰缺指标分别为<8.8mg/kg、8.8mg/kg^26.1mg/kg和>26.1mg/kg;湘东—湘中区为<9.3mg/kg、9.3mg/kg^26.1mg/kg和>26.1mg/kg;湘南为<4.0mg/kg、4.0mg/kg^19.4mg/kg和>19.4mg/kg。全省严重缺磷土壤较少,土壤磷素主要为中等水平,有15%左右的土壤速效磷含量较高。

120 field trails of phosphate fertilizer （P） application on early rice were conducted in main double-rice cropping regions of Hunan Province during 2005 to 2008. The objective of this research was to investigate the effect of P on early rice yield and profit, and to determine abundance and deficiency indices of soil available P. The results showed that P fertilizer application significantly increased early rice yield and profit compared with no P application. The ranking order of yield increase and profit rate among three study areas were the east-central region the north region the south region. Soil available P content significantly affected response in yield and profit with P application, and there were significantly negative correlations between yield increment, VCR and soil available P. The low, medium, high indices for soil available P in the north region were 8.8 mg/kg, 8.8-26.1 mg/kg and 26.1 mg/kg, and in the east-central region were 9.3 mg/kg, 9.3-26.1 mg/kg and 26.1mg/kg, and in the south region were 4.0 mg/kg, 4.0-19.4 mg/kg and 19.4 mg/ kg, respectively. The content of available P in the main area of whole province were at medium level, and in 15% of the whole area were at high level, only in small area were at low level.