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<blockquote data-quote="EmeraldCropSci" data-source="post: 149702" data-attributes="member: 1692"><p>No problem with rant - and scepticism is desirable in the area of crop nutrition where much snake oil abounds…</p><p></p><p>Apologies for the rather long response, but I felt your comments needed some consideration.</p><p></p><p>However, before responding directly I’d like to start by stating, for the record, that I qualified as a Soil Scientist from Reading University in 1980 and have worked as both a researcher and adviser in soils & crop nutrition around the World, especially in the areas of nutrient availability and crop uptake and their relationship to soil analysis methods. In other words, I hope I know something about this subject by now.</p><p></p><p>I know that this thread didn't start on the subject of Albrecht, but since you mentioned it and it does keep cropping up, I’d like to try to separate out some entanglements of truth and myth presented by some proponents of this. Unfortunately the conflation of solid fact with its core philosophy makes it difficult to pick out what is ‘real’ from a heap of statements.</p><p></p><p>Much of what is said is true and accepted in mainstream soil science. The presence of significant quantities of Ca, Mg and K in the soil is important to adequate crop growth. As I’ve said previously, P availability is affected by pH and, yes, Ca at higher pH is increasingly involved in sorbing P into a range of Ca-P minerals, making P increasingly unavailable. However, below pH 6.5 other minerals – mainly Al, Fe, Mn and silicates - are predominantly responsible for reactions with P making it increasingly unavailable as pH decreases. pH is the key determinant.</p><p></p><p>Stripping everything else away the key central claim within the Albrecht approach that differentiates it from accepted soil science is the assertion that there are strict confines of ‘ideal’ ratios for the major Cations (Ca, Mg & K) as a percentage of Base Saturation (Base Saturation Ratios) for total Cation Exchange Capacity (CEC) i.e. cationic balancing, particularly for Ca:Mg. This idea was based originally on limited research on soils in Missouri in the late 1930's and 1940's.</p><p></p><p>I could go on about this for a considerable time, however, there are a large number of scientific papers devoted to the refutation of this concept, particularly in recent times, such as the detailed reviews by Kopittke & Menzies (Soil Sci. Soc. Am. J. 71:259–265, 2007) or Simson et al. (Commun. Soil Sci. and Plant Anal. 10:153-162 1979), and I can probably do no better than quote from Dr D.C. Edmeades addressing the 26th Annual Conference of The Grassland Society in 2011 in his paper “Pseudo-science: a threat to agriculture?”:</p><p></p><p>“<em>Similarly, farmers … are being told by pseudo-scientists that the ‘old’ method of soil testing and fertiliser advice, which is based on scientific evidence, is out of-date and that a theory, suppressed for years by the establishment, has been rediscovered – Professor Albrecht’s Base Cation Ratio Theory is now in vogue. Once again this is pseudo-science in action for it is known that the Ratio Theory is, not only technically flawed, but results in grossly incorrect fertiliser advice and hence inefficient agricultural production.</em>”</p><p></p><p>Having said all that it is undoubtedly true that "available" soil K and Mg levels are important one to the other BUT NOT because of any Cation exchange effect in the soil, but because it has been established that the two ions compete with each other at the root surface and inside the root for uptake and distribution into the plant – in other words a cellular membrane antagonism. For this reason only, K:Mg levels in soil do need to be understood and adjustments made to fertiliser applications – usually Magnesium – for specific crops.</p><p></p><p></p><p>With respect to Phosphites and their activity, trial results are, as you say, limited. I shall dig some out and post them when I’ve done so.</p><p></p><p>Phosphite formulation is undoubtedly very important here – like any active chemical (e.g. a fungicide) the means (formulation) by which it is taken into a plant is crucial in delivering effectiveness. Nevertheless, in my experience and in the crop trials we’ve conducted and other research we’ve seen, specific formulations do have a marked positive benefit on rooting and yield, particularly where soil P levels are already deemed adequate. This is because the biostimulation effect that it has is not directly related to poor P nutrition. Some crops also respond better than others to Phosphites.</p><p></p><p></p><p>With respect to soil analysis, if you would like to submit soil samples for analysis and interpretation for a specific crop, then we’d be very happy to do so and I’d be very happy to discuss this with you further.</p></blockquote><p></p>
[QUOTE="EmeraldCropSci, post: 149702, member: 1692"] No problem with rant - and scepticism is desirable in the area of crop nutrition where much snake oil abounds… Apologies for the rather long response, but I felt your comments needed some consideration. However, before responding directly I’d like to start by stating, for the record, that I qualified as a Soil Scientist from Reading University in 1980 and have worked as both a researcher and adviser in soils & crop nutrition around the World, especially in the areas of nutrient availability and crop uptake and their relationship to soil analysis methods. In other words, I hope I know something about this subject by now. I know that this thread didn't start on the subject of Albrecht, but since you mentioned it and it does keep cropping up, I’d like to try to separate out some entanglements of truth and myth presented by some proponents of this. Unfortunately the conflation of solid fact with its core philosophy makes it difficult to pick out what is ‘real’ from a heap of statements. Much of what is said is true and accepted in mainstream soil science. The presence of significant quantities of Ca, Mg and K in the soil is important to adequate crop growth. As I’ve said previously, P availability is affected by pH and, yes, Ca at higher pH is increasingly involved in sorbing P into a range of Ca-P minerals, making P increasingly unavailable. However, below pH 6.5 other minerals – mainly Al, Fe, Mn and silicates - are predominantly responsible for reactions with P making it increasingly unavailable as pH decreases. pH is the key determinant. Stripping everything else away the key central claim within the Albrecht approach that differentiates it from accepted soil science is the assertion that there are strict confines of ‘ideal’ ratios for the major Cations (Ca, Mg & K) as a percentage of Base Saturation (Base Saturation Ratios) for total Cation Exchange Capacity (CEC) i.e. cationic balancing, particularly for Ca:Mg. This idea was based originally on limited research on soils in Missouri in the late 1930's and 1940's. I could go on about this for a considerable time, however, there are a large number of scientific papers devoted to the refutation of this concept, particularly in recent times, such as the detailed reviews by Kopittke & Menzies (Soil Sci. Soc. Am. J. 71:259–265, 2007) or Simson et al. (Commun. Soil Sci. and Plant Anal. 10:153-162 1979), and I can probably do no better than quote from Dr D.C. Edmeades addressing the 26th Annual Conference of The Grassland Society in 2011 in his paper “Pseudo-science: a threat to agriculture?”: “[I]Similarly, farmers … are being told by pseudo-scientists that the ‘old’ method of soil testing and fertiliser advice, which is based on scientific evidence, is out of-date and that a theory, suppressed for years by the establishment, has been rediscovered – Professor Albrecht’s Base Cation Ratio Theory is now in vogue. Once again this is pseudo-science in action for it is known that the Ratio Theory is, not only technically flawed, but results in grossly incorrect fertiliser advice and hence inefficient agricultural production.[/I]” Having said all that it is undoubtedly true that "available" soil K and Mg levels are important one to the other BUT NOT because of any Cation exchange effect in the soil, but because it has been established that the two ions compete with each other at the root surface and inside the root for uptake and distribution into the plant – in other words a cellular membrane antagonism. For this reason only, K:Mg levels in soil do need to be understood and adjustments made to fertiliser applications – usually Magnesium – for specific crops. With respect to Phosphites and their activity, trial results are, as you say, limited. I shall dig some out and post them when I’ve done so. Phosphite formulation is undoubtedly very important here – like any active chemical (e.g. a fungicide) the means (formulation) by which it is taken into a plant is crucial in delivering effectiveness. Nevertheless, in my experience and in the crop trials we’ve conducted and other research we’ve seen, specific formulations do have a marked positive benefit on rooting and yield, particularly where soil P levels are already deemed adequate. This is because the biostimulation effect that it has is not directly related to poor P nutrition. Some crops also respond better than others to Phosphites. With respect to soil analysis, if you would like to submit soil samples for analysis and interpretation for a specific crop, then we’d be very happy to do so and I’d be very happy to discuss this with you further. [/QUOTE]
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