Rape phosphate dressings

[EmeraldCropSci]

Several things making my head spin! Why don't roots grow upwards, sidewards? Gravity? So with seed dressings isn't the root always growing away from its nutrients? What decides the path the roots take? Osmosis? least resistance? Or magnetism? (manganese of course being one of the few magnetic elements) Is gravity simply a mass pull or do we move into the realms of quantum fields and the higgs bosun? buy me a drink and I won't mention it again.

You're right. Gravity is the driver and roots can detect the pull of gravity and react accordingly. There are vesicles within each plant cell that detect gravity. Experiments by NASA and others in free fall orbital experiments (which is not gravity free, but where everything is falling at the same rate together around the Earth in orbit) have shown that plant roots and shoots grow erratically unless given some other stimulus like light (for shoots) or spin (roots). Even so, growth tends to be spindly.

In soils roots also take paths dictated by soil structure and nutrient availability. It appears that some roots are more involved in scavenging nutrients, whilst others more involved in obtaining water. Negative influences like salinity, compaction, low oxygen or pathogens can further prevent root exploration.

 

[Andy Howard]

Then you add in paramagnetism. This encourages root growth and paramagnetic elements actually emit light which roots grow towards, one of most paramagnetic elements is oxygen.

 

[Dan Powell]

Then you add in paramagnetism. This encourages root growth and paramagnetic elements actually emit light which roots grow towards, one of most paramagnetic elements is oxygen.

There was something about this in Robert Plumb's latest newsletter.

If oxygen is the most paramagnetic element and roots are attracted to it, then why don't they grow up and out of the ground where there is plenty of it, unlike in the soil where there is a higher concentration of CO2. I sometimes wonder if he puts these concepts into his newsletters to test whether we can tell the difference between pseudoscience and actual science (i.e. how gullible we are). See also somatids.

 

[Andy Howard]

I read the book paramagnetism a couple of years ago by Dr Philip Callahan. Interesting read. I guess the only way of verifying the light emission is to put paramagnetic rock into a dark box and use slow exposure film and leave the film there for a week and then develop the film. Apparently it should show light emitting from the rock. This is a very low level light not a bulb.

 

[jammygit]

and pure anchorage? possibly an evolutionary theme

 

[EmeraldCropSci]

Then you add in paramagnetism. This encourages root growth and paramagnetic elements actually emit light which roots grow towards, one of most paramagnetic elements is oxygen.

Piffle. As far as I am aware there are absolutely no independent, replicated scientific studies published in any credible scientific journal that support this idea. Almost all elements and many compounds from Hydrogen to Tungsten are paramagnetic - that is they are attracted temporarily to some degree by an externally applied magnetic charge.

 

[CORK]

Placement of P can have a significant effect on crop growth and particularly early root establishment. However, this will depend greatly on the crop type in question, the cultivation/planting regime, current soil P availability (not necessarily related to P Indices!!), soil type and other soil chemistry characteristics.

P is only maximally available over a very short pH range due to a variety of complex soil chemistry reactions at either end of the pH spectrum. In any case P solubility and movement is highly limited within soils (in the range of 1 - 3 mm from granule).

Pure MAP is considerably more acidic than DAP and thus in a highly alkaline soil (pH above 7.3 for example) it is likely to create an acidic zone immediately around any MAP grain, making P and other nutrients in that zone more available in the short-term (3 months or so), such that placement is likely to have a positive effect. However, in a neutral to acid soil, DAP would be a better bet as it will encourage a slight lift in pH around the DAP grain. Nevertheless, neither should be placed where the fertiliser comes directly into contact with the seed.

Despite P Indices, P availability to the plant varies not only with pH but also with free Calcium, bicarbonate and reactions with a number of other soil minerals.

In the autumn we have found in trials that both OSR and WW respond very well additionally to particular forms of foliar P with other nutrients depending on specific soil analysis and that this encourages both better rooting and winter hardiness. This is particularly so where availability is an issue.

Well done Emerald, good to see some grounded advice.

I can't think of any discipline other than agriculture (besides human health) where there are so many products sold which can be best described as snake oil.

I don't confess to be a soil expert by any means despite having studied soil science as part of my B Ag degree at UCD.

The comment you make about P availability being limited by high pH is very interesting. We have the following situation on one farm;

Coastal sandy soil overlying red sandstone, arable with many many years, no organic manures used.

pH approaching at 7.9, soil P levels at a very high Index 4 (20mg/L !!!) due to my efforts to build soil levels.

Despite the high levels, the same parts of certain fields suffer from visual P deficiency in the spring (as the soil warms up, it does improve a bit).

We have always used the Teagasc (Morgans) test for the soils, however going by what you say this may not be the best route as it doesn't account for the pH effect.
To be fair to the Teagasc tests, we have built up our indices on the other land we farm (pH 6.5-6.7) and the crops are doing well.

I spoke to a Teagasc soil man lately who understood the problem and he recommended the Olsens test as it would be more suitable for the high pH situation. This is the plan.

So, my question is how do we make P available to the plants? I don't think we can lower the pH, this land has never received lime while I remember.

Also another observation that I have made on this farm; the deficiency occurs every second year in these areas. Is this something to do with the soil profile being inverted every year by the plough? I would have thought the soil should be well mixed after all these years. We plough to 10 inches.

This land is performing, despite its sandy nature it delivered 4.3t/ha of wosr in a terrible season last year and a stonking 9.2t/ha (16-17%mc) of spring barley this year!

All comments welcome!

 

[JNG]

Cork, do you know if we can test our soils using the Olsens method and use the results to comply with the Nitrates directive or does the directive only accept the Morgans method? Seems to me that Teagasc (or any lab/advisory service) should be testing pH first and then decide what type of test to perform according to the result!

 

[EmeraldCropSci]

Cork, do you know if we can test our soils using the Olsens method and use the results to comply with the Nitrates directive or does the directive only accept the Morgans method? Seems to me that Teagasc (or any lab/advisory service) should be testing pH first and then decide what type of test to perform according to the result!

As far as I'm aware Teagasc prescribe the Morgan's Method for soil P for all soils in the Rep. of Ireland (Olsen method is used in the North!) and all recommendations are based on this. I think that it would be very useful if Teagasc did advise use of Olsen for pH's above 6.5, but unfortunately do not. In my view this leads to the probability of considerably overestimating the amount of plant-available P above this pH and that this gets worse the higher the pH gets. This then probably leads to under-application of Phosphate for most crops.

Even the Olsen Method has its issues (as does any single method) in that no single extractant is able to distinguish between those soils that have just low P content and those which are low due to a high sorption capacity. This means that P recommendations based solely on P levels (or Indices) are likely to be inherently inaccurate in many cases.

 

[EmeraldCropSci]

Well done Emerald, good to see some grounded advice.

I can't think of any discipline other than agriculture (besides human health) where there are so many products sold which can be best described as snake oil.

I don't confess to be a soil expert by any means despite having studied soil science as part of my B Ag degree at UCD.

The comment you make about P availability being limited by high pH is very interesting. We have the following situation on one farm;

Coastal sandy soil overlying red sandstone, arable with many many years, no organic manures used.

pH approaching at 7.9, soil P levels at a very high Index 4 (20mg/L !!!) due to my efforts to build soil levels.

Despite the high levels, the same parts of certain fields suffer from visual P deficiency in the spring (as the soil warms up, it does improve a bit).

We have always used the Teagasc (Morgans) test for the soils, however going by what you say this may not be the best route as it doesn't account for the pH effect.
To be fair to the Teagasc tests, we have built up our indices on the other land we farm (pH 6.5-6.7) and the crops are doing well.

I spoke to a Teagasc soil man lately who understood the problem and he recommended the Olsens test as it would be more suitable for the high pH situation. This is the plan.

So, my question is how do we make P available to the plants? I don't think we can lower the pH, this land has never received lime while I remember.

Also another observation that I have made on this farm; the deficiency occurs every second year in these areas. Is this something to do with the soil profile being inverted every year by the plough? I would have thought the soil should be well mixed after all these years. We plough to 10 inches.

This land is performing, despite its sandy nature it delivered 4.3t/ha of wosr in a terrible season last year and a stonking 9.2t/ha (16-17%mc) of spring barley this year!

All comments welcome!

@CORK, as we discussed, part of the issue currently is trying to understand what's going on from limited information and with more than a few important parameters missing. If you'd like to investigate this further through more detailed soil analysis and a consideration of the generic soil type and crop needs then please let me know.

 

[jon9000]

Gosh..... Are we still talking about farming or test tubes?,?,!

 

[tw15]

We do the harvesting for a friend down the road and only mentioned to him the other day that i noticed he can grow very good wheat then has good barley but always seems to struggle with osr not badly mind but as he says that's the one that seems not to perform as it should. Well we got talking and he puts human sludge on after rape and i suggested even though his indices are good it looks to me that he might be running out of p that far in to the rotation . Around here wessex water were saying in theory if we put sludge on we do it every 3 years . I suspect on these chalk soils it is getting locked up or used all available p before the rape in his rotation . We all know it gets locked up very quickly and it doesn't move far in the soil . For this reason we are trying putting a bit of p down under the row at drilling Don't bother for spring wheat as this gets chicken
muck.Rape has had 80 kg of dap ha at drilling might get a small dressing of chicken muck on in the spring .
winter wheats seem to be responding to a bit of placed p as well.
Our indicies are p 2+, k3 PH AROUND 7-8.5 on most ground.

 

[EmeraldCropSci]

Gosh..... Are we still talking about farming or test tubes?,?,!

I take your point and the aim is to entirely practical. But you've got to really understand the problem before you spend money tackling it.

Just to illustrate: the genetic potential of wheat is around 23 t/ha. The World average is under 3 t/ha. The UK average is just a shade under 8 t/ha (about 35% of potential). Some guys get 11 or 12 t/ha. OK, light, temperature, rainfall, soil type all play their part, but the rest is to a very large degree in our control and we ought to be able to do better.

Despite better varieties, the use of modern pesticides, precision farming techniques and NPK fertiliser guides from DEFRA etc. yields for major combinable crops have not increased for nearly 15 years.

So our focus is to bring attention to the areas of crop science that have been widely ignored, despite the large amount of research that's been done around the World, and to turn this into practical advice and action.

 

[Brisel]

Most of my Wessex Water sewage digestate goes on after wheat before spring barley which is often followed by osr. In theory that means that much of the P is available to the osr but mine doesn't perform that well either. Sewage ahead of osr gave the best crop of rape I have grown here on similar pH soils to your friend. What precludes the sewage ahead of osr has been timeliness of getting the contractors in to spread it before early establishment of the osr.

23 t/ha of sewage digestate normally gives circa 120 kg/ha P2O5, not all of which is available to the next crop.

My theory on the relatively poor performance of the osr is to do with very little topsoil in places & lots of pigeons!

Yield maps show plenty of parts of the fields doing 6 t/ha but this is balanced out by far too much doing a lot less than that. SOYL nutrient maps don't always correlate with yield maps but then again the 1 ha grid sampling method isn't really representative of what is actually there. I will be more interested to do more zonal sampling according to soil type next time the sampling is due. Kriging creates a picture but a totally guesstimated one.

 

[Andy Howard]

Well done Emerald, good to see some grounded advice.

I can't think of any discipline other than agriculture (besides human health) where there are so many products sold which can be best described as snake oil.

Hang on a minute. I do not know Simon at all and I am sure he is a genuine bloke but he has come on here as emerald crop science not Simon Fox. This company sells products which according to their website the trials are ongoing and I can not see any results. The products on the face of it seem to be very similar to other products on the market and even have similar names. He is on here promoting his company with all this free advice. A salesman no? I may use these products if they prove worth while only time will tell. Simon do you have independent trial results to share with us? As a user of very similar products I would be interested

 

[JNG]

We do the harvesting for a friend down the road and only mentioned to him the other day that i noticed he can grow very good wheat then has good barley but always seems to struggle with osr not badly mind but as he says that's the one that seems not to perform as it should. Well we got talking and he puts human sludge on after rape and i suggested even though his indices are good it looks to me that he might be running out of p that far in to the rotation . Around here wessex water were saying in theory if we put sludge on we do it every 3 years . I suspect on these chalk soils it is getting locked up or used all available p before the rape in his rotation . We all know it gets locked up very quickly and it doesn't move far in the soil . For this reason we are trying putting a bit of p down under the row at drilling Don't bother for spring wheat as this gets chicken
muck.Rape has had 80 kg of dap ha at drilling might get a small dressing of chicken muck on in the spring .
winter wheats seem to be responding to a bit of placed p as well.
Our indicies are p 2+, k3 PH AROUND 7-8.5 on most ground.

Will be interested to see the results? Keep us informed!

 

[CORK]

Hang on a minute. I do not know Simon at all and I am sure he is a genuine bloke but he has come on here as emerald crop science not Simon Fox. This company sells products which according to their website the trials are ongoing and I can not see any results. The products on the face of it seem to be very similar to other products on the market and even have similar names. He is on here promoting his company with all this free advice. A salesman no? I may use these products if they prove worth while only time will tell. Simon do you have independent trial results to share with us? As a user of very similar products I would be interested

I agree independent trial results would be good to see, it seems to be almost impossible to find such results on nutritional products in general,

I was merely complimenting Simon on his nutritional commentary which to me seems to align itself well with the independent information that I have thus far received during my education and professional career ( I am in the trade as well as a farmer). To be honest, this makes a refreshing change from the methods used by some companies.

As far as I am concerned, products must prove themselves in practice.

 

[Andy Howard]

I agree with what he is saying too as we already use this approach. If we get back to the opening post for me P release is temperature and biology driven, treat your soil with care, supply the bugs with food and this will help your P supply. Phosphites are different. Just look at what Gave Brown does. Craps soil results but plenty available nutrients to plants.

 

[shakerator]

As Andy says Many of these "phosphate" seed dressings are actually phosphite which isn't even plant available p.

Positive results from PGA take off type materials probably from suppression of root pathogens rather than P uptake...

Placement fert good for weed control but largely spin offs from areas with strict phosphates legislation?

 

[SilliamWhale]

Hang on a minute. I do not know Simon at all and I am sure he is a genuine bloke but he has come on here as emerald crop science not Simon Fox. This company sells products which according to their website the trials are ongoing and I can not see any results. The products on the face of it seem to be very similar to other products on the market and even have similar names. He is on here promoting his company with all this free advice. A salesman no? I may use these products if they prove worth while only time will tell. Simon do you have independent trial results to share with us? As a user of very similar products I would be interested

Yes I agree. I'm interested and generally find agreement with Emerald on a lot of things but I also want to know what is different about what he has? I don't think we always have to go down the route of trial results necessarily though.