Dr.Hepperly,you have asked very relevant question  and current question of( my )interest.Perception of individuals or countries vary with their economic status and the reserves of  rock phosphate they have.Even countries in Europe or North America and to some extent China have accumulated P in their soils.Soils in rest of many countries in Asia, Africa(though some of them have P reserves) and South America may have low P status .For sustainable food-grain production,food and nutritional security,P fertilizer use is indispensable.Even if the P reserves can last for more years then predicted by different scientists,the reserves are not evenly distributed and huge  country like India is endowed with limited amount  inferior quality rock phosphates.Soil  P(native soil P and accumulated P) biological mobilization using efficient root systems,microorganisms including mycorrhizae , P solubilizing fungi and bacterial species is very important. Tailoring  plants with utmost economic use of P for their growth,and higher crop production is receiving attention.I think composts enriched with rock phosphate and P mobilizing  microbes are promising in the present context along with efficient fertilizer use.

Phosphate solubilizing microbes and Earth worm can be manipulated at gene level by genetic engineering to enhance their capability to mobilize the P resources which are abundant in soil.

Both the mineral and soil resources are limited, so we must put more effort into recycling and recovery.  Research in these directions is important in the global context because plants need more P to respond to their full potential to elevated atmospheric CO2 concentrations, which will be with us for the forseeable future.

Thank you Paul for stressing the need to close the nutrient cycle loop by conclusively recovering waste streams manures and residues.

When it comes to solubilizing rock phosphate we can better exploit the mycorrhizal capacity, rhizosphere Phosphorus solubilizing bacteria and better understand and utilize the mycorrhizosphere including the plant, fungus and bacterial components.

It comes to mind that Phosphorus can be mobilized by humic and fulvic acids and can be located in close proximity to the seed and transplants and have much less ability to be lost except through soil erosion.

Since the Phosphorus nutrition can be critical to optimizing legume growth and Biological Nitrification I believe it is not given the emphasis it needs for optimizing our cropping systems Rhizobium bacteria are stars in Nitrogen fixation and also aid in Phosphorus mobilization and high a high Phosphorus requirement.

I recently saw a claim that humic acids can increase solubility of rock phosphate up to 2.5 times. Of the crops that really have high Phosphorus demand the tomato and potato crops come to mind.

My own personal experience in biologically based farming systems is that we can provide the Nitrogen needs by rotational or cover cropping but it is more difficult how we will be able to optimize our food crops without additions of Phosphorus amendment strategically.

When plants are well colonized with mycorrhizae their Phosphorus requirement needed by additions can be much less. I have seen very complete nutritional responses from worm castings and great success with a mixture of castings and leaf manure compost to give season long complete crop nutrition.

Losses of nutrients when compost is used are much less than using raw manures directly.

As Doctor Rao pointed out the majority of high quality phosphate resources are found in Morrocco and there considerable concern about their ability to be transferred to areas most in need which are old soils in humid tropical zones and the like.

Sometimes we like to concentrate on one thing like Phosphorus but by our selective attention we may miss that Plant, Fungi, Bacteria animals are all co workers. When we as human provide the habitats for these often hidden workers our labor might be reduced and our returns as farmers and eaters maximized.

Thank you again for your keen inputs and insights.

Fertilizing with rock P will always be to some extend an unsustainable waste of valuable P resources. Biological treats ma increase teporaily the release of some of the lesser strong bound P in rock minerals, but never will be able to make it plant available in total. Some uncertainty in practical P fertilization derives from the fact that there are no experimental means to estimate the true long-term utilization of fertilizer P. The traditional concepts (differential and radioisotope method) suggest that on an average only 75% of the fertilizer P applied is finally used by plants, implicating that always more P has to be fertilized than will be recovered by agricultural products. The breakthrough towards the possibility of a complete utilization and thus also a complete recycling of fertilizer P came with an empirical approach published in 1965 by the Finnish scientist Armi Kaila, for which the term “apparent utilization” has been coined. Based on Kaila´s hypothesis P fertilization concepts can be designed, which guarantee a full utilization of fertilizer P in agriculture. There is, however, one crucial prerequisite for a 100% utilization which is that the entire P in a fertilizer has to be completely water soluble or at least soluble in neutral ammonium citrate solution.

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Phosphorus: Essential to Life—Are We Running Out?

by Renee Cho|April 1, 2013

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Fertilizing a corn field in Iowa. Photo credit: U.S. Department of Agriculture

Fertilizing a corn field in Iowa. Photo credit: U.S. Department of Agriculture

Phosphorus, the 11th most common element on earth, is fundamental to all living things. It is essential for the creation of DNA, cell membranes, and for bone and teeth formation in humans. It is vital for food production since it is one of three nutrients (nitrogen, potassium and phosphorus) used in commercial fertilizer. Phosphorus cannot be manufactured or destroyed, and there is no substitute or synthetic version of it available. There has been an ongoing debate about whether or not we are running out of phosphorus. Are we approaching peak phosphorus? In other words, are we using it up faster than we can economically extract it?

In fact, phosphorus is a renewable resource and there is plenty of it left on earth. Animals and humans excrete almost 100 percent of the phosphorus they consume in food. In the past, as part of a natural cycle, the phosphorus in manure and waste was returned to the soil to aid in crop production. Today phosphorus is an essential component of commercial fertilizer. Because industrial agriculture moves food around the world for processing and consumption, disrupting the natural cycle that returned phosphorus to the soil via the decomposition of plants, in many areas fertilizer must now be continually applied to enrich the soil’s nutrients.

Most of the phosphorus used in fertilizer comes from phosphate rock, a finite resource formed over millions of years in the earth’s crust. Ninety percent of the world’s mined phosphate rock is used in agriculture and food production, mostly as fertilizer, less as animal feed and food additives. When experts debate peak phosphorus, what they are usually debating is how long the phosphate rock reserves, i.e. the resources that can economically be extracted, will hold out.

Pedro Sanchez, director of the Agriculture and Food Security Center at the Earth Institute, does not believe there is a shortage of phosphorus. “In my long 50-year career, “ he said. “Once every decade, people say we are going to run out of phosphorus. Each time this is disproven. All the most reliable estimates show that we have enough phosphate rock resources to last between 300 and 400 more years.”

In 2010, the International Fertilizer Development Center determined that phosphate rock reserves would last for several centuries. In 2011, the U.S. Geological Survey revised its estimates of phosphate rock reserves from the previous 17.63 billion tons to 71.65 billion tons in accordance with IFDC’s estimates. And, according to Sanchez, new research shows that the amount of phosphorus coming to the surface by tectonic uplift is in the same range as the amounts of phosphate rock we are extracting now.

Global meat consumption from 1961 to 2009. Photo credit: FAO

Global meat consumption from 1961 to 2009. Photo credit: FAO

The duration of phosphate rock reserves will also be impacted by the decreasing quality of the reserves, the growing global population, increased meat and dairy consumption (which require more fertilized grain for feed), wastage along the food chain, new technologies, deposit discoveries and improvements in agricultural efficiency and the recycling of phosphorus. Moreover, climate change will affect the demand for phosphorus because agriculture will bear the brunt of changing weather patterns. Most experts agree, however, that the quality and accessibility of currently available phosphate rock reserves are declining, and the costs to mine, refine, store and transport them are rising.

Ninety percent of the phosphate rock reserves are located in just five countries: Morocco, China, South Africa, Jordan and the United States. The U.S., which has 25 years of phosphate rock reserves left, imports a substantial amount of phosphate rock from Morocco, which controls up to 85 percent of the remaining phosphate rock reserves. However, many of Morocco’s mines are located in Western Sahara, which Morocco has occupied against international law. Despite the prevalence of phosphorus on earth, only a small percentage of it can be mined because of physical, economic, energy or legal constraints.

In 2008, phosphate rock prices spiked 800 percent because of higher oil prices, increased demand for fertilizer (due to more meat consumption) and biofuels, and a short-term lack of availability of phosphate rock. This led to surging food prices, which hit developing countries particularly hard.

With a world population that is projected to reach 9 billion by 2050 and require 70 percent more food than we produce today, and a growing global middle class that is consuming more meat and dairy, phosphorus is crucial to global food security. Yet, there are no international organizations or regulations that manage global phosphorus resources. Since global demand for phosphorus rises about 3 percent each year (and may increase as the global middle class grows and consumes more meat), our ability to feed humanity will depend upon how we manage our phosphorus resources.

Unfortunately, most phosphorus is wasted. Only 20 percent of the phosphorus in phosphate rock reaches the food consumed globally. Thirty to 40 percent is lost during mining and processing; 50 percent is wasted in the food chain between farm and fork; and only half of all manure is recycled back into farmland around the world.

Eutrophication in the Caspian Sea. Photo credit: Jeff Schmaltz, NASA

Eutrophication in the Caspian Sea. Photo credit: Jeff Schmaltz, NASA

Most of the wasted phosphorus enters our rivers, lakes and oceans from agricultural or manure runoff or from phosphates in detergent and soda dumped down drains, resulting in eutrophication. This is a serious form of water pollution wherein algae bloom, then die, consuming oxygen and creating a “dead zone” where nothing can live. Over 400 coastal dead zones at the mouths of rivers exist and are expanding at the rate of 10 percent per decade. In the United States alone, economic damage from eutrophication is estimated to be $2.2 billion a year.

As the quality of phosphate rock reserves declines, more energy is necessary to mine and process it. The processing of lower grade phosphate rock also produces more heavy metals such as cadmium and uranium, which are toxic to soil and humans; more energy must be expended to remove them as well. Moreover, increasingly expensive fossil fuels are needed to transport approximately 30 million tons of phosphate rock and fertilizers around the world annually.

Sanchez says that while there is no reason to fear we are running out of phosphorus, we do need to be more efficient about our use of phosphorus, especially to minimize eutrophication. The keys to making our phosphorus resources more sustainable are to reduce demand and find alternate sources. We need to:

•Improve the efficiency of mining

•Integrate livestock and crop production; in other words, use the manure as fertilizer

•Make fertilizer application more targeted

•Prevent soil erosion and agricultural runoff by promoting no-till farming, terracing, contour tilling and the use of windbreaks

•Eat a plant based diet

•Reduce food waste from farm to fork

•Recover phosphorus from human waste

Cow dung to be used as fertilizer drying in Punjab. Photo credit: Gopal Aggarwal http://gopal1035.blogspot.com

Cow dung to be used as fertilizer drying in Punjab. Photo credit: Gopal Aggarwal http://gopal1035.blogspot.com

Phosphorus can be reused. According to some studies, there are enough nutrients in one person’s urine to grow 50 to 100 percent of the food needed by another person. NuReSys is a Belgian company whose technology can recover 85 percent of the phosphorus present in wastewater, and turn it into struvite crystals that can be used as a slow fertilizer.

New phosphorus-efficient crops are also being developed. Scientists at the International Rice Research Institute discovered a gene that makes it possible for rice plants to grow bigger roots that absorb more phosphorus. The overexpression of this gene can increase the yield of rice plants when they are grown in phosphorus-poor soil. Rice plants with this gene are not genetically modified, but are being bred with modern techniques; they are expected to be available to farmers in a few years.

A breed of genetically modified Yorkshire pigs, called the Enviropig, has been developed by the University of Guelph in Canada to digest phosphorus from plants more efficiently and excrete less of it. This results in lower costs to feed the pigs and less phosphorus pollution, since pig manure is a major contributor to eutrophication. Last spring, however, the Enviropigs were euthanized after the scientists lost their funding.

The Agriculture and Food Security Center is working on food security in Africa and attempting to eliminate hunger there and throughout the tropics within the next two to three decades.

In the mountains of Tanzania along Lake Manyara, Sanchez’ team has discovered deposits of “minjingu,” high-quality phosphate rock that is cheaper and just as efficient as triple super phosphate (a highly concentrated phosphate-based fertilizer) in terms of yields of corn per hectare.

Minjingu Mines & Fertilisers Ltd.. Photo credit: IFDC Photography

Minjingu Mines & Fertilisers Ltd.. Photo credit: IFDC Photography

Minjingu deposits are formed by the excreta and dead bodies of cormorants and other birds that roost and die in the mountains, forming biogenic rock phosphate or guano deposits. Guano, the feces and urine of seabirds (and bats), has a high phosphorus content, and in the past was often used as fertilizer.

Sanchez’ researchers have also discovered a common bush called the Mexican Sunflower that is an efficient phosphorus collector. It grows by the side of the road, fertilized by the excreta dumped there by farmers. The farmers cut it down and use it as green manure, an organic phosphorus fertilizer which helps grow high-quality crops like vegetables.

Mexican Sunflower. Photo credit: John Tann

Mexican Sunflower. Photo credit: John Tann

The Agriculture and Food Security Center team also helps farmers contain erosion and runoff by encouraging them to keep some vegetative cover, either alive or dead, on the soil year-round. This is done through intercropping, leaving crop residue in the fields, contour planting on slopes or terracing.

“There is no data to support the idea of peak phosphorus,” said Sanchez. “Just fears. New deposits are continually being discovered. We also have more efficient extraction that is getting more phosphate rock out of land-based sediments. And there is an enormous 49-gigaton deposit of phosphorus in the continental shelf from Florida to Maritime Canada that scientists have known about for years. Now there is some experimental extraction going on off the coast of North Carolina.”

Pedro Sanchez, author of Properties and Management of Soils in the Tropics published in 1976, which continues to be a bestseller, is currently working on Tropical Soils Science, an update of his previous work. It will be published by 2015.

Tags: eutrophicationFertilizerfood securityphosphate rockPhosphorus

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3 thoughts on “Phosphorus: Essential to Life—Are We Running Out?”

James

| July 16, 2015 at 5:23 am

Phosphorus is one of the vital nutrient that is needed for life to continue. Plants and Animals require phosphorus for their survival. It is essential for the creation of DNA, cell membranes, and for bone and teeth formation in humans. It is vital for food production since it is one of three nutrients (nitrogen, potassium and phosphorus) used in commercial fertilizer. Phosphorus cannot be manufactured or destroyed, and there is no substitute or synthetic version of it available.Thanks for sharing with us.

wachiuri

| July 20, 2015 at 4:08 am

thank you for revealing those facts. esp that of a persons excreation and urine could produce up to 100% phosphorous enough to grow another persons food, it is a shame that in some excreta is buried underground

Mel

| October 15, 2015 at 2:54 pm

The article was one of the more considered views of the subject of phosphate resources and alternative solutions to its use / over-use.

However, one key missing discussion point is the geo-political reality of where phosphate resources are located. From Western Sahara across North Africa and into the Middle East, virtually all of these countries are subject to radical Islamic terror pressure. Just as the well know consequences of the OPEC cartel has had on global standards of living, the fertilizer cartels for Potash and now Phosphate are of strategic danger to food production.

The article mentions production disruption in 2008 leading to food riots in developing nations…it was the Moroccan OCP who were responsible for this warning shot felt across the globe. Also consider that China now has its own concerns of depletion of its higher quality phosphate reserves. Thus, global supply is in reality a half-baked argument…the geo-political over-lay is the greater danger to food production and those countries with large populations living on the verge of starvation can take little solace from notional reserves or recycling potential. Climate change is only going to accelerate the process.

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An important discussion is going on pertaining to Phosphorus nutrition (application and utilization). Two of my colleague at University of Agriculture, Faisalabad, Pakistan concluded the about 90-95 % residual P in soils precipitated with soil lime in calcareous alkaline irrigated soils of Punjab. They also proposed certain ways to mobilize it economically. They worked to identify P-efficient utilizing crops and their varieties. Unfortunately both these scholars ( Dr. Rehmat Ullah and Dr. Maqsood Ahmad Gill). But I will try to find their papers on the subject and try to make available for benefits and for planning future research.

Very interesting discussion on  a very important issue considering the fact that major proportion of applied P enters into different  insoluble forms , that keeps on accumulating  year after year , without any correct  gauge on the magnitude of this source of P in the soil . The biological strategy would be  multipronged strategy , which include:  exploit the diversity existing within P-solubilising bacteria , fungus ; harness the AMs diversity with a better culturing and inoculation technique ; regular use of green manure crop as part of floor management ; crop residue management developing waste- to- wealth  concept and introduction of legume crop in the cropping system . With these initiative , a  field friendly handy monitoring parameters with regard to various insoluble  P-forms of soil, depending upon soil type must also be given a fresh look.    

Perhaps as the Doctors point out many pronged approaches will be needed to crack the very hard nut of Phosphorus immobility and fixation.

It comes to mind that very fine grinding attention to rock sources combined with better mycorrhizae and P solubilizing bacteria are important.

I would bring up the role of plants which are good at mobilizing P sources Pigeonpea has some renown for the tropics and buckwheat in temperate areas.

I would reiterate the advantage of humates and fulvic acid and the ability to provide pH buffering to optimize availability based on neutral or slightly acid without having overly alkaline or acid soil conditions.

The use of many factors together is often referred to the many little hammer approach. Sometimes we try in vain looking for single factors and get discouraged but many of these complex issues are aided by employing multiple factor synergism and getting a thorough brain storming.

Ironically we are in a scarcity situation and at the same time less than one half of anything added is ever utilized efficiently.

No doubt the topic of discussion is very important and of practical point of view but still it is very difficult to mobilize fixed or unsoluble/ less soluble P from sources like rock phosphate. Successes obtained are on particular soils and results obtained are crop specific. However, many openings have been recommended by learned researchers. We have to select the package keeping in view the prevailing conditions where it must be tested on small scale before recommending on large scale.

Dr Nazir , you raised a very good point . How much can we rely on residual P in soil ?. Is there any parameter available ,except the  agronomic crop response to monitor the changes in residual P fraction of the soil . There is no doubt , some of the crops and soils respond excellently to applied phosphorous . Alfisols are considered most responsive to applied P , while Vertisols the least . Whether such crop responses  are dictated by the size of the residual P fraction of soil ?. Can we balance the amount of P to be applied in next season crop based on size of residual soil p fraction ? .Enclosing two PDFs  for further reading on these aspects.  

Dr Nazir you raised a very pertinent point . How does residual  P of soil respond to different crops and soils ?.  Vertisols by virtue of greater P-adsorption capacity respond least to P-input , while Alfisols are the first soil type responding to P-application . How can we monitor the build-up of residual P sink of the soil ? How differentially residual responds to different crops and soils?.

Long term experiment on response of residual P showed a minimum time lag of 10-13 years are required to develop a equilibrium , and that equilibrium shifts temporally  . These experiments also established that application of N is equally important o harness the residual P of the soil .  I am enclosing some of the very interesting PDFs highlighting these aspects .

Professo Paul J.A. Withers and their group proposed the 5R stewardship,a strategic frame work to tackle global phosphorus inefficiency involving Re-align P inputs,Reduce P losses,Recycle P in bio resources,Recover P in wastes and Redefine P in food systems.The current question concerns more with recycling of P in organic resources or wastes.Dr.Paul highlighted the need for recycling and recovering P in wastes .Dr.Hepperly has attached lot of new information from earth institute.As per the comments of Renee Cho,one company from Belgium NuReSys has technology to recover up to 85%of P from urine ,indicating lot of scope to recover P from waste.I mentioned about the concentration of rock phosphates in only few countries and uneven distribution across globe.There is uneven distribution in P fertilizer use also.There is large scale transfer of P from  mineral reserves to far away areas of concentrated animal and food production systems in developed countries.30% of global P deficient areas are not receiving sufficient P fertilizers for sustainable food production in those countries.Most of the surplus manure is the in developed countries and most of the sewage and sludge P is there as waste in highly populated cities.So for recovering P one has to concentrate in cities.Similarly for recycling P from manures we have to concentrate on dairy farms where lot of dung and urine are produced.So the efficient use fertilizer P and direct or treated rock phosphates use are important in developing countries.Biological systems may play a great role in mobilizing insoluble P in rock phosphates and insoluble P accumulated in soil as a result of fertilizer P use over years.Some of our participants have highlighted genetic improvement in crop plants, microorganisms and earthworms for efficient mobilization of insoluble The current statistics indicate that we have now rock phosphate  reserves to last up to 300-400 years.But how stop wasting P in mine -manufacturing -fertilization -crop-animal and human system is a big question.40% P is wasted in mining and processing,50%in food chain from farm to fork and only 50% of manure P is recycled to farmland.Of the applied fertilizer P, 50-75% may remaining in soil.

Professor Paul J.A. Withers and their group proposed the 5R stewardship,a strategic frame work to tackle global phosphorus inefficiency involving Re-align P inputs,Reduce P losses,Recycle P in bio resources,Recover P in wastes and Redefine P in food systems.The current question concerns more with recycling of P in organic resources or wastes.Dr.Paul highlighted the need for recycling and recovering P in wastes .Dr.Hepperly has attached lot of new information from earth institute.As per the comments of Renee Cho,one company from Belgium NuReSys has technology to recover up to 85%of P from urine ,indicating lot of scope to recover P from waste.I mentioned about the concentration of rock phosphates in only few countries and uneven distribution across globe.There is uneven distribution in P fertilizer use also.There is large scale transfer of P from  mineral reserves to far away areas of concentrated animal and food production systems in developed countries.30% of global P deficient areas are not receiving sufficient P fertilizers for sustainable food production in those countries.Most of the surplus manure is the in developed countries and most of the sewage and sludge P is there as waste in highly populated cities.So for recovering P one has to concentrate in cities.Similarly for recycling P from manures we have to concentrate on dairy farms where lot of dung and urine are produced.So the efficient use fertilizer P and direct or treated rock phosphates use are important in developing countries.Biological systems may play a great role in mobilizing insoluble P in rock phosphates and insoluble P accumulated in soil as a result of fertilizer P use over years.Some of our participants have highlighted genetic improvement in crop plants, microorganisms and earthworms for efficient mobilization of insoluble The current statistics indicate that we have now rock phosphate  reserves to last up to 300-400 years.But how stop wasting P in mine -manufacturing -fertilization -crop-animal and human system is a big question.40% P is wasted in mining and processing,50%in food chain from farm to fork and only 50% of manure P is recycled to farmland.Of the applied fertilizer P, 50-75% may remaining in soil.

Dear colleagues, as promised  in my previous answer, few paper are given below along with one full paper..

1.     Akhtar, M.S., M. Nishigaki, Y. Oki, T. Adachi, Y. Nakashima, G. Murtaza, T. Aziz, M. Sabir, Saifullah, M.A. Maqsood, Z. Rehman, A. Wakeel, Y. Nakamot, 2013, Solublization and Acquisition of phosphorus from Sparingly Soluble P-Sources, and differential growth response of Brassica Cultivars exposed to P-Stress Environment. , Commun. Soil Sci. Plant Anal. , 44, 1242-1258

2.     Aziz, T., I. Ahmad, M. Farooq, M. A. Maqsood and M. Sabir. , 2011, Variation in phosphorus efficiency among brassica cultivars 1: growth, internal utilization and phosphorus remobilization. , Journal of Plant Nutrition , 34, 2006-2017

3.     Aziz, T., Rahmatullah, M. Aamer Maqsood, M. Sabir, and S. Kanwal, 2011, Categorization of brassica cultivars for phosphorus acquisition from phosphate rock on basis of growth and ionic parameters., J. Plant Nutr., 34, 522-533

4.     Hafeez, F., T. Aziz, M.A. Maqsood, M. Ahmed and M. Farooq, 2010, Differences in rice cultivars for growth and phosphorus acquisition from rock phosphate and mono-ammonium phosphate sources. , Int. J. Agric. Biol., 12, 907-910

5.     Ashraf, M., Rahmatullah, M.A. Maqsood, S. Kanwal, M.A. Tahir and L. Ali. , 2009, Growth Responses of Wheat Cultivars to Rock Phosphate in Hydroponics . , , 19:, 398-402.

6.     Mujeeb, F., Rahmatullah, J. Akhtar, and R.Ahmad, 2010, Integration of organic and inorganic P sources for improving P use efficiency in different soils. , Soil Environ. , 29, 122-127

Dr.Ghafoor good sources of information on rice ,wheat and mustard crop varieties for their efficiency to utilize P from soluble and insoluble sources.Studies on root systems of the efficient genotypes may throw more light on reasons for such efficiency in utilization of P especially from insoluble sources of P.

We have recently discussed some the issues related to P use efficiency in soil-plant-animal/human systems in researchgate which may be seen for more information.

How can I efficiently utilize legacy(residual) phosphorus in soil for crop production?

How can I improve phosphorus use efficiency in soil-plant-animal/human system?

Which method for calculation of fertilizer phosphorus use efficiency is better?

Can anyone suggest methods for phosphorus recovery from sewage waters and sludge in cities?

How do I adequately meet the phosphorus needs of cereal crops in reproduction stage?

a PhD I supervised may give you the answers you are looking for: http://e-collection.library.ethz.ch/view/eth:8669?q=%28keywords_en:PHOSPHORUS%20CYCLE%29

Dr.Schnug,I could go through the summary and contents of the thesis of your student .It is an excellent piece of work which very thoroughly examines the current status of phosphorus in all aspects..I shall leisurely read the whole thesis.I wholeheartedly compliment your student for this excellent work.

Since we are continuing to explore the P otentials and P itfalls of Phosphorus I am attaching an article on oil palm in an acid ultisol which shows the ability of compost of the oil palm waste to ameliorate the Aluminum issues and increase P efficiency.

When we address Carbon issues a beneficial side effect is the reductions of limiting toxicities while simultaneously we can achieve better crop quality from a more complete nutrient base. It seems that compared to N particularly P has not be emphasized much.

If we optimize P our concerns about N can be resolved when we have productive legumes increasing soil N from BNF.  Organic systems concentrate on the legume and the residual effect increases the yield and quality for the cereals and non legumes.

The issues with P are also challenges are also opportunities kind of like the Chines pictogram of crisis that has two symbols one being danger and the other opportunity.

I understand that organic manure and composts  have  a definite  role not only in providing P,facilitating release,solubilization or mobilization of P(also micronutrients).Of course N I need not highlight.Organic manure(because of humus ) can complex and detoxify Al or other heavy metals.They  resist change in PH or increase PH of acid soils.I agree with your comments.But one question unanswered or not properly answered is ,why the percent P utilization by crops from manures is low?

Interesting discussion.  By analogy with N, I wonder if the availability of P in manures may also be related to C availability? 

Dr.Paul,will it be C:P ratio or labile carbon  or freshly added carbon to soil.What factors are  limiting P  mineralization?Is it immobilization or  sorption of released P by soil P sorprtion sites or precipitation with soluble Al or Fe(only in (strongly acid soils).

Dear Paul Milham,

Carbon can be associated with both Nitrogen and Phosphate Cycles and their availabilities.

The big difference is while both Carbon and Nitrogen can be biologically transformed into atmospheric phases Phosphorus has no gas phase.

Our ability to keep Phosphorus Carbon and Nitrogen partly resides in our ability to prevent our regenerative depositions not exceeding our erosion losses. In that way we more than sustainable regenerating the system through the soil.

 In relation to Phosphorus role in soil erosion can be one biggest challenges. When manures are used raw the volatility of Ammonia can be very concerning in both P, C and N the use of clay amendment and brown materials as well as Calcium can work to conserve the volatile losses of manure N and C and P.

Ideally the use of amended composts can reduce the nutrient losses and conserve. United States Geological Survey Misc. Publ. 1228 attributes 59% of excess Nitrogen in the Chesapeake Basin to fertilizer use mainly in Maize production, and over 80% of the residual losses of Nitrogen have been traces to raw manure application also on Maize.

If we optimize the Maize production using hairy vetch we can eliminate the need for any synthetic Nitrogen for the Maize crop. When raw manures are composted especially with proper amendments the issues with nutrient losses are overcome. When cover crops are used the soil losses are much less than the gains and the soil organic matter and allied nutrients all increase according.   

Folks,

My dream for Phosphorus solution in relation solubilities is a synergistic strategy for insoluble Phosphorus would be to better combine  biology with soil chemistry.

1) mycorrhizal fungi with

2) Phosphorus solubilizing bacteria

 Ideally this inoculum would be a seed zone treatment including appropriate mycorrhizal spores, Bacillus Phosphorus solubizing strains. 3) Rhizobia for legumes and 4) humic materials as amendment.

Still believe that the need to address pH is largely ignored to our detriment.

I believe we need to revisit the mycorhizosphere and its synergies related to these issues.

Thanks for all your wonderful insights.

Paul very interesting point , you have added into the idscussion. I still remember such discussion came while discussing about the addition of phosphorous in the compost , whether or not it will release the phosphorous and improve the manure quality. C:N  and C:P ratio could be an anlogue to  each other with respect to compost maturity , but of the two , C:N ratio undoubtedly better index. 

Doctor Srivastava,

How much do you think mycorrhiza if they were optimized could alleviate Zinc deficiency by improving Zinc efficiency?

I was looking at some Bacillus work showing a 300% increase in solubility in culture filtrate I imagine that could be significant.

Do you know any hard work on this in an applied sense? I like the theory but I really love the application.

In relation to our intelligence we tend to sector things out.... Carbon Water Phosphorus cycles as if they have independence Yet in some ways this is totally our own construction.

Our thinking limits our intentions.

Can we think out of box or book and try to look at things with fresh eyes?

When we study do were fall in our own artificially constructs. They can create their own limitations. In some ways the we need to strive for understanding what seems beyond understanding. Then we will truly know that we know so little and that might be the real high knowledge.

See this!

I could only go through the abstract/summary of the paper.It appears that the rockphosphate P  is not mobilized in the presence of sulphur (acidifying) and P solubilzing microorganism in incubation study.Am I correct?

you may get the full paper through this channel dr. Rao: http://www.tandfonline.com/doi/abs/10.1080/00103624.2012.708073.

The idea of in situ mobilization sounds intriguing,, but has a number of issues to be considered like an increased simultaneous mobilization and uptake of hazardous heavy metals from the rock phosphate. But also here please remember again, there is no way to check experimentally the long term utilization of the entire amount of P applied: the S:P ratio in the granules need to be over stoichiometri, to achieve the complete conversion of insoluble to watersoluble P at least theoretically. There are better ways to for future P fertilizer production from rock phospahtes. Have a look here: http://philjournalsci.dost.gov.ph/vol144no1/energy%20neutral%20phosphate%20fertilizer%20production.html

Dr.Schnug,I appreciate your view point and literature you have provided.Yesterday I saw several of your very good publications on phosphorus,the radioactive  uranium problem ,heavy metals and other pollutants in manures and amendments which goes to soil.The need or opportunity to go for rock phosphates direct use or after treating or amending with organic manures, is carbonate containing rock phosphates can be solubilzed in acid soils and can directly be used,low- grade rock phosphates which can not be used in fertilizer industry can be used with organics.Even if uranium in rock phosphate is problem it can be diluted when used on millions of landholdings.(?)Reports from India and some other countries indicate mobilization of rock phosphate P  in phosphocompost,possibly because of fungi, organic acids and humus production.Insoluble P is converted into citrate soluble P which is plant -available.The following is one of the earlier publications from India.

Http://www.researchgate.net/publication/235788327_Effect_of_phosphocompost_on_the_yield_and_P_uptake_of_red_gram(Cajanus_cajan(L.)_Millsp.))

Article Effect of phosphocompost on the yield and P uptake of red gr...

I am so sorry Dr Hepperly for responding little late , since the discussion has gone bit ahead. I fully endorse your opinion about the strong intervention of microbes in mobilising such vast pool of soil phosphorous. Role of phosphate solubilizing microbes (PDF enclosed) including AMs in this regard cannot be overlooked . Please look at the secondary effect of phosphate solubilisation , dont you think , along with phosphate solubilisation , other   nutrients like Fe , Mn, Zn  are also simultaneously solubilized . AMs are the classical example in this matter. Development of microbial substrate ( PDF enclosed ) another very good option in solubilizing such insoluble resource of phosphorous. Please find enclosed two relevant PDFs for further reading in this matter.  

Paul , I still believe the best biological strategy would be to develop a comprehensive microbial substrate involving phosphate solubilizing bacteria  and fungi , and solubilisation be enacted on the soil on a regular basis . Such an attempt will act  in two ways , one reducing the insoluble bank of soil phosphorous , building up year after year due blanket fertilizer recommendation and we infact,  hardly look at it while prescribing fertilizer recommendation ; and secondly due to better phosphorous -use-efficiency , such strategy will not allow the build-up of insoluble  phosphorous fraction in the soil , where we have to be so much concerned  about such  insoluble fraction of soil  phosphorous.

I think synergistic interaction of VAM and rhizobia is one of the biological strategy which solve this problem. In order to achieve this goal, interaction between these two should be highly positive.   

Dear Farook and Anoop, I agree with both of you that symbiosis and a rhizosphere consortium would have great potential for Phosphorus solubilization issues. In all of these cases I believe the mixture of broadly adapted strains for Rhizobia, Glomus type mycorrhizae, and finally for rhizosphere team perhaps a combo of Bacillus and Trichoderma strains. Ideally this would be able to be introduced on seed and in drip line right where it would be needed. For all the wonder insights on this area of interest I want to express my gratitude and appreciation. Thank you for your kind efforts. Paul Reed Hepperly

Dear colleagues ,can anybody explain how the N fixing rhizobia help in solubilizing insoluble P in soil?What symbiosis is there among different microbes which soubililize or mobilize soil insoluble P?What the microbes share among themselves?Is it carbon or anything else?

Dear Doctor Rao,

The Rhizobia bacteria are Phosphate Solubilizing bacteria. Growth in vitro showing clearing zones in media with insoluble Phosphate base.

Beyond that  literature also shows a synergistic relationship between plant, Rhizobia and mycorrhiza as tripartite integrated system. As such Rhizobia is part and parcel of a powerful system of Carbon, Nitrogen and  Phosphate mobilization team.

When Rhizobia are fully engaged the plant system is not limited by Nitrogen insufficiency Carbon fixation is more efficient. As the plant is more efficient in allocating Carbon to the Mycorhizal symbiont as it is released from soil Nitrogen insufficiency and Carbon soil insufficiency are both addressed. Without that N insufficiency Carbon fixation is the plant is better activated and engaged. These factors do not work apart but together.

The biological capacity of the bulk soil is both Carbon Nitrogen and Phosphorus limited. All of these work together to optimize the entire system.  Rhizobium helps photosynthesis overcoming prevalent Nitrogen deficiency. Without Nitrogen limitation C photosynthesis moves more product to soil exudates. Improved  feeding of  soil mycorrhizal component by increased Carbon mobilizations. Without Carbon insufficiency Mycorrhizal component feed plants better with Phosphate and water.

Rhizobacteria are also important in this equation and the Mycorhizosphere is now being described to illustrate the inter relation of a complex of factors involved.

While we often look at things are being separated for ease of understanding and discussion when it comes to legumes Rhizobia and mycorrhizae they are all inter related and cannot be viewed as being separate but united into complex powerful system.

To understand the complex cycles involved in our planetary "organism" biogeochemical cycles have been described as part of a Global Organism hypothesis of Gaia.

That's how I see these results however flawed and I am sure the concepts are rapidly changing and people will revisualize these concepts many times during the next years.

Dr.Hepperly,I very much appreciate your excellent comments/response.They are educative and informative especially for young readers/viewers.

Thank you for your consensus view of the importance of tripartite approaches where fungi, bacteria, and plant work together. mobilizing and optimizing Phosphorus reactions.

Recently I saw this publication 

Zaller, J. G, et al 2014 Glyphosate affects the belowground interaction between the earthworm and arbuscular mycorrhizal fungi in a model system. Science Reports 4:5634.

Bottomline is that earthworms are to made sluggish in the presence of glyphosale which is used on millions of hectares around the world and the manufacturers tout as non-toxic without side effects. The effect of not having earthworm nor arbuscular mycorrhizae and in the presence of glyphosate causing an 80% reduction of drainage percolation compared to the earthworm and mycorrhizae inoculated with no roundup. 

Beside the tripartite view of fungi bacteria and plant it would appear that quadripartite relations including the earthworm which is a soil engineer fundamental to microbial interaction. 

Work in Australia show that elimination of termites led to 80% reduction in soil nitrogen levels. Termites are known for biological nitrogen fixation in their gut which allows them to nourish themselves in low Nitrogen materials which are high in Carbon. 

Mycorrhizae could optimize plant response using about 25% of the phosphate needed as when mycorrhizae are absent.

 Since biological interaction is so important the use of inputs which compromise them is highlighted. Perhaps the need is to stop detrimental practices which compromise native fertility. 

We also need to understanding better living is through biological mechanisms and chemical approaches are adjuncts. 

What do you think?

 Dr.Hepperly, interesting information.We need to create awareness  among farmers about certain practices which are harmful to soil soil microbes / other organisms.Probably farmers are seeing  their convenience and clean field,not what is happening below ground.Even our agronomists need to pay attention to certain practices which may have long term negative effects.

The positive and negative impacts of soil microbes and earth worms are related to problems getting their measurement and visualization and have proper experimental controls. Natural soils are filled with positive organisms and only through their selective removal can their effects be determined. 

A strict screeening of microbes , called rhizocompetent microbes would surely avoid the negative impacts upon microbial inoculation..We need to havea robust module of screening microbes , their complementarity with other microbes...and so on

Informative answer by Dr. Kumar.

Thanks Dr Nazir for appreciation. Dr Hepperly and other friends, when we look at microbial turnover of phosphorous using such rhizocompetent micorbes, how far single inoculation has helped in accomplishing this stupendous task ...? Therefore , we need comprehensively  tested multiple inoculation , and repeated inoculation  possibly at certain specific phenological growth stage of a crop where the crop  is undergoing through maximum metabolic activity of roots ...

Let me initiate some discussion on this very important issue...

Mineral Phosphate Solubilization: Concepts and Prospects in Sustainable

Agriculture ,Proc Indian Natn Sci Acad 80 No. 2 June 2014 Spl. Sec. pp. 389-405,DOI: 10.16943/ptinsa/2014/v80i2/55116

Microorganisms play very important role in biogeochemical cycle in soil, which reflects the plant growth and influence t he agri cult ural pr oducti on. Phos phat e s ol ubili zi ng mi cr oor ganis ms ( PS M) are ver y i mport ant t o t he pl ants under phos phor us stress. As we know, Phosphorus is one of the essential  acronutrients, along with nitrogen, required by the plants for their vit al functi ons and survi val. But, t he effi ci ency of phosphati c fertili zers i s very l ow due t o t heir fi xati on i n bot h aci di c and alkaline soils which are predominant in India. Therefore, the inoculation of mineral phosphate solubilizers and other useful microbial inoculants in these soils would play an important role to restore the overall balance of nutrients and health of the soil to sustain it for posterity. The molecular genetics and mechanism of mineral phosphate solubilization and their efficiency in releasing phosphates for plant uptake is seemingly different and varies with microorganisms. Hence, the isolation and characterization of superior strains of mineral phosphate solubilizers to suit different soil types is imperative. These phos phat e-s ol ubili zi ng bact eri a have t he capacit y t o convert t he i ns ol ubl e f or ms of phos phor us i nt o it s s ol ubl e f or m, whi ch ulti mat el y gets avail abl e t o pl ants, a pheno menon oft en referred t o as mi neral phosphat e sol ubilisati on. The combination of chemical fertilizers with this beneficial microorganism is also one of the ways to increase the agricultural yield without loss of nutrients. Moreover, the develop ments of co mmercial bioinoculants will be greatly accepted by far mers and will hel p t o mai nt ai n agri cult ure sust ai nabilit y. The present arti cl e descri bes t he pr ogress of research i n t his area and future insights about use of such biophores in agriculture. The review has highlighted as many 54 species of PSBs releasing a range of oragnic acids like Gluconic, succinic, acetic, glutamic, oxaloacetic, pyruvic, malic, fumaric, alpha-ketoglutaric 2-ketogluconic acid , Tartaric, citric caid etc...worth reading review...PDF enclosed..

In combining rhizo and soil competence with high efficacy in response the use of consortia and blends are needed. Each soil with its individual issues and potentials has a microbiome which should be searched out. In Rhizobium inoculation, it is customary to use 6 to 12 strains to ensure some will survive and take. Indeed from a bacterial viewpoint, the bacterial genome has ability to readily interchange genetic material to help this adaptation process. The developing of these consortia are a key because no one strain or species can provide the agricultural services we are looking for. Indeed we need to shed a commodity approach and learn to think in multiple component systems which have changing and dynamic natures. 

A small amount of phosphorus delivered to the seedling area have a marked effect as starterfertilizer.

This might give a lot of bang per input buck I also think as long as were at it provide other inputs to get the best start to help the plants then can have a more adaptive response based on enhanced root systems.