rule of thumb: 45, 7, 40, 7 ! To be honest: there are so many factors affecting nutrient utilisation from organic sources, it fills entire lectures!

Dr.Schnug, why do you expect so low use efficiencies for phosphorus and sulphur from organic sources?

I certainly agree with Prof. Schnug's statement.  Of related interest perhaps, my Department funded the development of a software tool called MANNER-NPK which provides estimates of crop available nutrients from various organic materials - essentially average figures based on numerous field trials and other experiments conducted in the UK over the past 20 years or so.  It's available free of charge from here, although it is necessary to register first - http://www.planet4farmers.co.uk/Manner.  More technical details can be seen in the paper here - doi: 10.1111/sum.12078.

Thank Dr.Murray for information and soft ware. I shall definitely go through the same.Still Iam not convinced of so low values for both for Phosphorus and sulphur. I request other colleagues for their experience with these two nutrients.

Under arid environment we are getting the use efficiency in the order N:42-48%, P: 13-20%, K: 40-46% and S: 10-12%.

• The figures are even lower on soild with a high nutritional status of those elements and maybe higher on those poorly supplied. Best to find it out for your own situation: make your own experiments!

Dr Subba Rao, I was referring to the latter part of Prof. Schnug's comment, I don't have any data on nutrient use efficiency per se.  I have seen that a recent review of the subject was published  last year in Advances in Agronomy vol 128, pp. 137-180.  I don't have a copy, but it would worth trying to track down I expect.

Dr.Murray, I shall try to get the information from Advances in Agronomy publication.Drs Tarafdar and Schnug, we are aware that biological systems mobilize soil P through root exudates, organic acids,protons, hydrolying enzymes like phosphatages and phytages,P inherently present in organic manures in soluble form,mineralized from manure and mobilzed from soil are available to plant when organic manures are added to soil.Then, why the plant is not able to utilize available nutrient source.As sulphur adsorption is not prblem in soils having pH greater than 5,why sulphur use efficiency is low.Is calculated efficiency low because of less P requirement  by crop and more P application through manure . In soybean-wheat system with application of 4 and 8 tonnes of manure  we recorded much higher P use efficiencies.

Colleagues, I wish to add a few points related to nutrient use efficiency from organic manures. Earlier organic manures are recommended on the basis of their N content/concentration.That practice led to accumulation of P in agricultural soils in European countries. As I understand now there are restrictions on the total amount of mamure to be loaded and recommendation to add manure on the basis of P concentration.Then ,the question is how to meet the N and P requirements of crops in organic farming as the N addition is restricted and P use efficiency is low?Another problem is limited solubility of rock phosphate ,except in acid soils and fertilizer P is not allowed in organic farming.

Though I can not answer this question, I would say the same as Dr. Murry Hart mentioned about Prof. Schnug's comments. I believe it is very contextual. Even same field with same amount of input would give different result in two different seasons and/or for two different crops. Last year we studied P retention and leaching potentials for two mineral and an organic soil which were amended with composted horse manure(Geoderma Regional 5, 209-214. doi: 10.1016/j.geodrs.2015.08.003). The manure had 26% DRP and  39% water soluble P. The results were as expected for mineral soils but organic soil surprised us. All the load were retained in the organic soil.

Dr.Mohammed,organic soils may behave differently from normal mineral soil amended with organic manure.In organic soil probably the high amount of humus may retain the P through cation(like calcium) linkages .This type of humus complex ed P may be available to crop.Have you made any crop P uptake studies in that soil?

Thank you Dr. Subba Rao. We have thought about the mechanism you mentioned. Alternative possibility we thought is a rapid microbial immobilization due to incorporation of fresh and easily degradable organic matter. Unfortunately we have not made the full investigation. We are planning for new experiment to see the crop performance, changes in microbial community and measure CO2 and GHG fluxes.

Something to add to Dr. Rao´s comment on the low values for utilization coefficients I gave further up. Those values are for the year of application: Once I did an extensive metad data analysis on experiments addressing utilization coefficients (see in my portfoloio "Die Ausnutzung von Düngernährstoffen und die Bedeutung des Ausnutzungsgrades für die Höhe der Düngung", in German, sorry, but you may get informations already from the graphs there). For N for instance, you will find everything between 0-100%, but for P a much smaller bandwith in the lower ranges.K follows very much N. S is a speciality, its low utilization coefficients comes from a combination of heigh mobility in the soil matrix related to infiltration and soil water movement and a metabolic controlled limitation in uptake, especially in species without a significant secondary S metabolism. You find plenty of literature to S fertilization and S uptake in my portfolio as well. In terms of sustainability not the utilization by the first crop but the one over an infinite time is much more interesting: however tracking nutrients over  more than one vegetation period requires stable isotopes. For N nd S we know that on top of the utilization in the year of application we gain another few %, especially through what has been saved in the OM of the soil. For P there is no experimental approach on long lasting utilization possible, because differiental fertilizing trials dont work and no isotopes suitable for tracking over longer periods are availab. However, we assume that in case a number of to a number of factors are given (mainly that the P is water soluble or completly organic bound) a complete utilization of P over an infinite time is achievable. This is part of a new doktrin for P fertilizer quality, which is coinde: P 100% / zero, says, 100 utilization of P without contamination (heavy metals and organic xenobiotics). Look in our portfolio, or watch our new book "P 100% / zero" appearing at Springer in spring 2016.

no problem with N, but not possible with P.

Thank you Dr .Schnug for your well illustrated reply.The use efficiencies of P and S reported in India are in the range of 15-25 and 8-12,respectively with fertilizer applications.Of course these figures are for single year/season studies,not cumulative for number of years.As highlighted by your group/team and also Syers group from Rothamsted,near 100 P use efficiency is  possible under continuous cropping and P fertilization.As I understand when the soil test values reach adequate level the  the P uptake values may become equal to the P added in that particular year.When soil P fixation /sorption sites are saturated, the P  will be in readily available form, most of the time.Also the the leaching losses may be small or minimum. So plant can use greater amount of P from fertilizer and some amount from soil,may be from previous P fertilization and this process goes on well as long as we fertilize the crop with P fertilizer at least equal to P removal from soil.In case of S, the losses from  soil system and low plant S utilization from available source may matter.

Hello Mr Annangi Subba Rao,

here I send you some links from grassland and forage crops trials in Austria dealing with some NUE nitrogen use efficency. 

Formerly we in AUSTRIA used in the agricultural exention services NUE was from 15% for compost, 30% for solid maure and 50-80% for manure and 90% for urine.

Now our very environmantal attached researches want now tell us manure N has a mostly 100% efficieny in grassland. Which ist demonstated in the paper below in 

http://www.raumberg-gumpenstein.at/cm4/de/forschung/publikationen/downloadsveranstaltungen/finish/860-umweltressourcen-im-gruenland/12311-zur-wirksamkeit-von-wirtschaftsduengern-im-gruenland.html

Stickstoff-Mineraldüngeräquivalent von organischen Düngern-Nitrogen fertilizer equivalent of organic fertilizers,N industry paper:

http://www.effizientduengen.de/download/Newsletter_10_2011.pdf

My grassland professor made this studies:

SCHECHTNER, G., 1978. Zur Wirksamkeit des Güllestickstoffs auf dem Grünland in Abhängigkeit

vom Düngungsregime. Die Bodenkultur, 29, 4, 351-376.

SCHECHTNER, G., 1981. Nährstoffwirkungen und Sonderwirkungen der Gülle. 7.Arbeits-tagung

"Fragen der Güllerei", Gumpenstein, 135-196.

SCHECHTNER, G., 1992. Pflanzenbauliche Bewertung des Wirtschaftsdüngerstickstoffs. Der

Förderungsdienst, 3, 13-21.

=

Schechtner, G., 1978. The effectiveness of manure nitrogen on grassland depending

from fertilization regimes. The Agricultural Sciences, 29, 4, 351-376.

Schechtner, G., 1981. Nutrient effects and special effects of the manure. 7.Arbeits-meeting

"Questions of Güllerei" Gumpenstein, 135-196.

Schechtner, G., 1992. Agronomic evaluation of manure nitrogen. Of the

Promotion Service, 3, 13-21.

Sorry the papers are in only in German, as our grassland researchers are not very aquainted to publish in English.

J HUMER, Austria

https://diebodenkultur.boku.ac.at/volltexte/band-49/heft-1/poetsch.pdf

http://www.raumberg-gumpenstein.at/cm4/de/component/jdownloads/finish/1693-2311-wirtschaftsduengerversuch/14771-einfluss-unterschiedlicher-duengungsintensitaeten-auf-standortbedingte-naehrstoffauswaschungen-im-feldfutterbau.html

http://www.raumberg-gumpenstein.at/cm4/de/forschung/publikationen/downloadsveranstaltungen/finish/860-umweltressourcen-im-gruenland/12311-zur-wirksamkeit-von-wirtschaftsduengern-im-gruenland.html

http://www.effizientduengen.de/download/Newsletter_10_2011.pdf

http://www.raumberg-gumpenstein.at/cm4/de/component/jdownloads/finish/860-umweltressourcen-im-gruenland/12311-zur-wirksamkeit-von-wirtschaftsduengern-im-gruenland.html?Itemid=0

Article Revealing N management intensity on grassland farms based on...

Conference Paper Richtlinien für die sachgerechte Düngung in Österreich, SGD6...

Thank you very much for the literature attached, Dr.Johann.