摘要
土壤养分和作物产量间呈S形而非线性生长效应,养分指标的阈值是科学施肥和土壤肥力综合评价之关键.近30 年的长期定位试验因大量的养分和产量梯度数据而成为养分指标阈值研究的最佳载体.本研究基于江西进贤红壤性稻田长期定位化肥、有机肥和旱地化肥试验监测数据,采用频率累积曲线、生长效应曲线和专家成果借鉴等多种方法,系统研究了有机质(OM)、全氮(TN)、速效氮(AN)、全磷(TP)、速效磷(AP)、全钾(TK)、速效钾(AK)和pH等8 项指标阈值.结果表明,养分指标与作物产量呈显著或极显著生长效应关系,并得出相应模拟方程,评价指标阈值:OM 30 g/kg、TN 2.0 g/kg、AN 200 mg/kg、TP 1.2 g/kg、AP 20 mg/kg、TK 14 g/kg、AK 100 mg/kg、pH 4.5(下)/6.5(上),可供红壤区参考施肥和土壤肥力评价.
Abstract
The relationship between soil nutrients and crop yields is S-shaped and non-linear,thus,i-dentifying threshold value of nutrient index is crucial for scientific fertilization and comprehensive evaluation of soil fertility.With extensive gradient data on nutrients and yields over the past 30 years,long-term fertilization experiments have emerged as optimal platforms for studying nutrients threshold.Based on the monitoring data from long-term fertilization experiments conducted with fertilizer and manure in reddish paddy soil,and with fertilizer in red upland soil at Jinxian county,Jiangxi province,we used different methods including frequency accumulation curve,growth effect curve and experts achievement reference to systematically determine the threshold values of organic matter(OM),total nitrogen(TN),available nitrogen(AN),total phosphorus(TP),available phosphorus(AP),total potassium(TK),available potassium(AK)and pH value.The results showed significant or extremely significant growth-effect relationship(obtained corresponding simulation equations)be-tween nutrient indexes and crop yields.The determined thresholds were OM 30g/kg,TN 2.0g/kg,AN 200mg/kg,TP 1.2g/kg,AP 20mg/kg,TK 14g/kg,AK 100mg/kg and pH 4.5(low)and 6.5(high),respectively.These findings can serve as a reference for fertilization practices and soil fertility assessments in red soil region.
NETL
NSTL
万方数据