• ISSN 1008-505X
  • CN 11-3996/S
郭斗斗, 黄绍敏, 张水清, 张珂珂, 宋晓. 潮土小麦和玉米Olsen-P农学阈值及其差异分析[J]. 植物营养与肥料学报, 2017, 23(5): 1184-1190. DOI: 10.11674/zwyf.17043
引用本文: 郭斗斗, 黄绍敏, 张水清, 张珂珂, 宋晓. 潮土小麦和玉米Olsen-P农学阈值及其差异分析[J]. 植物营养与肥料学报, 2017, 23(5): 1184-1190. DOI: 10.11674/zwyf.17043
GUO Dou-dou, HUANG Shao-min, ZHANG Shui-qing, ZHANG Ke-ke, SONG Xiao. Threshold values of soil Olsen-P for maize and wheat in fluvo-aquic soil[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(5): 1184-1190. DOI: 10.11674/zwyf.17043
Citation: GUO Dou-dou, HUANG Shao-min, ZHANG Shui-qing, ZHANG Ke-ke, SONG Xiao. Threshold values of soil Olsen-P for maize and wheat in fluvo-aquic soil[J]. Journal of Plant Nutrition and Fertilizers, 2017, 23(5): 1184-1190. DOI: 10.11674/zwyf.17043

潮土小麦和玉米Olsen-P农学阈值及其差异分析

Threshold values of soil Olsen-P for maize and wheat in fluvo-aquic soil

  • 摘要:
    目的磷农学阈值是指导不同作物磷肥用量并获取最佳经济产量的重要依据,然而,不同地区不同的耕作制度、土壤类型、作物种类、pH、温湿度条件下,作物的磷农学阈值不同。明确小麦–玉米轮作体系下,典型潮土区小麦和玉米的磷农学阈值,并分析其差异。
    方法本研究基于“国家潮土土壤肥力与肥料效益长期监测站”25年的定位试验,选取氮、钾肥施用充足和磷肥用量不同的NK (不施磷肥)、NPK (施用氮磷钾化肥)、NPKM (氮磷钾化肥和有机肥配施)、1.5NPKM (高量氮磷钾化肥配施有机肥)、NPKS (氮磷钾化肥与玉米秸秆还田配施) 5个处理的试验数据,使用米切里西指数模型 (Mitscherlich exponential model) 拟合小麦和玉米的Olsen-P农学阈值,并通过对比不同土壤磷水平下两种作物的磷吸收利用特性,分析其阈值不同的原因。
    结果获得最大相对产量的95%时,潮土区小麦Olsen-P农学阈值为13.1 mg/kg,玉米Olsen-P农学阈值为7.5 mg/kg。玉米Olsen-P农学阈值低于小麦主要原因:1) 土壤磷水平较低时,小麦对磷缺乏更为敏感,而玉米可保持相对较强的吸磷能力,25年不施磷处理玉米吸磷量是小麦的1.4倍;2) 土壤Olsen-P含量达到玉米阈值,而未能达到小麦阈值时,可保障玉米籽粒、茎秆及小麦籽粒正常生长对磷的需求,但小麦茎秆磷浓度仅能达到相对最大磷浓度的68.9%,严重影响了小麦的正常生长和获取较高产量的能力;土壤Olsen-P含量提高到小麦阈值后,小麦茎秆磷浓度提高到相对最大磷浓度的80.5%以上,进而可保障小麦获得较高的产量;3) 土壤磷素养分充足时,小麦对磷的吸收量大于玉米,且主要是由于小麦茎秆磷浓度和吸磷量随土壤Olsen-P含量的增加而大幅度增加。
    结论小麦和玉米作为典型潮土区两种重要的粮食作物,Olsen-P农学阈值分别为13.1和7.5 mg/kg。由于两种作物的生理特性不同,小麦对磷素的吸收利用率较低,茎秆需要较高的土壤磷浓度维持正常生长,产量形成对磷养分需求更大。因此,小麦–玉米轮作体系下,小麦的磷农学阈值更高,小麦季所需土壤磷供应量大于玉米季。为增强磷肥利用效率,减少磷肥投入量和土壤中磷素的过量累积,玉米季磷肥使用量应适当小于小麦季。当土壤Olsen-P水平高于作物磷农学阈值后,减少或短时间停止施用磷肥并不会对作物产量有明显影响。

     

    Abstract:
    ObjectivesCritical soil P levels are important basis for guiding phosphate fertilizer rate and obtaining the best economic benefits for different crops, however, critical soil P values may vary among different crops because of different areas, farming systems, soil types, pH, temperature and humidity conditions. Critical values of soil Olsen-P between maize and wheat in a wheat-maize rotation system in typical fluvo-aquic soil area were determined and analyzed in this studay.
    MethodsThis study was based on a 25 year fertilization experiment on " National Long-term Monitoring Station of Fluvo-aquic Soil Fertility and Fertilizer Effects”. Five fertilization treatments were investigated: NK, NPK, NPK plus farmyard manure (NPKM), 1.5 times of application rates of N, P, K plus farmyard manure (1.5NPKM) and N, P, K plus maize straw (NPKS). The critical values of soil Olsen-P for crop yields were calculated using the Mitscherlich exponential model, and the absorption and utilization characteristics of phosphorus in two crops under different soil phosphorus levels were compared.
    ResultsCorrespond to 95% of the maximum predicted relative yields, the critical value of Olsen-P was 13.1 mg/kg for wheat and 7.5 mg/kg for maize. The critical value of Olsen-P for maize was lower than that for wheat, and the reasons were: 1) When the soil phosphorus level was low, wheat was more sensitive to the phosphorus deficiency, while maize could maintain a relatively strong ability to absorb phosphorus. Total phosphorus absorption for maize was 1.4 times of wheat in no P fertilization treatment for 25 years. 2) When the content of soil Olsen-P reached the critical value for maize and did not reach the critical value for wheat, the requirement of phosphorus for maize grain, maize straw and wheat grain could be ensured, but the P concentration of wheat straw could only reach 68.9% of the relative maximum P concentration, which seriously affected the normal growth and high yield formation of wheat. When the soil Olsen-P content was increased to the wheat critical value, the P concentration of wheat straw increased to 80.5% of the relative maximum P concentration, and the high yield of wheat could be ensured. 3) When there was adequate soil phosphorus nutrient, the amount of phosphorus absorbed by wheat was higher than that of maize, mainly because with the increase of soil Olsen-P content, the wheat straw P concentration and P uptake amount were greatly increased.
    ConclusionsThe critical values of Olsen-P for wheat and maize were 13.1 and 7.5 mg/kg respectively in the typical fluvo-aquic soil. Wheat was relatively less efficient than maize in the absorption and utilization of soil P. Wheat straw needed higher P concentration to maintain normal growth, and needed stronger soil phosphorus supply accordingly for high yield.

     

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