摘要： 土壤养分丰缺指标的建立及养分丰缺等级的划分是测土施肥工作的基本环节。田间相关研究表明，对于京郊潮土类土壤，最好的土壤有效磷提取剂是0.5M碳酸氢钠。小麦植株的相对吸磷量与用此法测定的土壤有效磷含量之间的相关系数可达0.810^**；酸性提取剂如盐酸氟化铵等不适于本地区土壤。土壤有效钾的提取剂可用1N醋酸铵，土壤碱解氮含量测定值与小麦相对产量间有中等程度的相关。
用上述各种提取剂对潮土类土壤中氮磷钾养分进行测试，并与小麦的相对产量进行校验，就可得出潮土类土壤中氮磷钾养分含量丰缺的等级。根据土壤有效磷的丰缺等级，将多点肥料效应试验数据进行归类，得出各个丰缺等级的肥料效应方程，可以用来对小麦施肥进行推荐。

关键词: 小麦, 测土施肥, 北京

Abstract: 1.A correlative research confirms that,for extraction of soil available phosphate in alluvial soil,the best extractive solution is Olsen’s 0.5M NaH-CO3.The correlative coefficient between soil extractive phosphate and the up -take of phosphate by wheat crops is 0.810; Bray’s extractive solution is not suited for this type of soil.For soil available potassium,the best extractive solution is IN Ammonium acetate.The method of 1.6N NaOH hydrolytic nitrogen is suited for soil testing in alluvial soil of Beijing area.
2.From the field’s calibrative experiments,the calibration for soil fertility of alluvial soil is:
K₂O <20ppm 20-40ppm 41-100ppm 101-180ppm >180ppm
3.Based on the calibration of soil available phosphate,the equations of fertilizer response are obtained as follow:P₂O₅<5ppm Y=359.884+1.43lN-0.007N2 + 1.192P-0.0057P2+0.0013NP P2O55-15ppm Y=377.244+1.570N-0.0045N2 + L.286P-0.005P2-6.0027NP P20516-30ppm Y=408.782+1.820N-0.0045N2 + 1.786P-0.0158P2-0.0006NP P205>30ppm Y = 472.087 + 2.278N-0.0092N2 + 1.866P-0.0154P2-0.000003NP
4.According to the calibration of soil available nutrients and the fertilizer response equations,the recommendation of NPK fertilizer is obtained.NP206very low<60ppm<5ppmlow60-80ppm5-15ppmmedium81-130ppm16-30ppmhigh131-160ppm31-50ppmvery high>160ppm>50ppm