A theory for fertilizer response
A theory for fertilizer response
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肥料反应理论
DOI：
--
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发表时间：
1971
影响因子：
0.6
通讯作者：
J. Hunt
中科院分区：
文献类型：
--
作者：
D. J. Greenwood;J. Wood;T. Cleaver;J. Hunt
总结得出一个模型，该模型将产量与施肥水平相关，参数具有直接的物理意义。N8、P8和K8定义了土壤对植物生长所需的氮、磷和钾供应的贡献; BN、BP和BK定义了在低营养水平下对氮、磷和钾肥的反应，aN是足够提高渗透压以防止生长所需的氮水平。为了验证该模型，进行了田间试验，其中125个不同的氮，磷，钾肥水平的组合，在菜豆和夏甘蓝进行。每个实验的每个区组的产量数据与模型拟合得非常好。拟合值因区组而异，但这些差异可归因于这样一个事实，即对于每个区组，通常使用差异很大的参数值获得同样良好的拟合。N8的估计是从化学分析的（NH 4 + NO3）- N的土壤样品从田间小区，和P8，和K8从化学研究的磷和钾的吸附在未经处理的土壤。它们与通过完全不同的将模型拟合到产量数据的程序获得的平均值基本一致。此外，BN，BP和BK和aN从其他化学研究的估计值是一致的，通过模型拟合得到的。结果表明，该理论虽然有一定的局限性，但它与详细的现场试验结果基本雅阁。
SUMMARY A model is derived that relates yield to levels of applied fertilizer in terms of parameters that have direct physical meaning. N8, P8, and K8 define the contribution of the soil to the supply of nitrogen, phosphorus and potassium for plant growth; BN, BP and BK define the responses to nitrogen, phosphorus and potassium fertilizer at low nutrient levels and aN is the level of nitrogen required to raise the osmotic pressure sufficiently to prevent growth. To test the model, field experiments were carried out on French beans and summer cabbage in which 125 different combinations of levels of nitrogen, phosphate and potassium fertilizers were applied. The yield data from each block of each experiment fitted the model very well. Fitted values differed from block to block but these differences could be attributed to the fact that for each block equally good fits were often obtained with widely differing parameter values. Estimates of N8 were made from chemical analysis of the (NH4 + NO3) — N of soil samples from the field plots, and P8, and K8 from chemical studies of the adsorption of phosphate and potassium on untreated soil. They were in substantial agreement with the average values obtained by the entirely different procedure of fitting the model to the yield data. Also estimated values for BN, BP and BK and aN from other chemical studies were consistent with those obtained by model fitting. It is concluded that although the theory has limitations it is broadly in accord with the results of the detailed field experiments.