I live in the state of Santa Catarina, southern Brazil. My state is the largest producer of pigs and uses a lot of swine manure in the soil. Our state laws limit the use of pig wastes by quantity (50 m3/ha/year), but this system does not work because it does not take into account the content of P in manure nor the previous P content in the soil. So, we have many environmental problems related to excess manure used in soil, as eutrophication. In research, we are trying to find alternatives to it and the two most promising would be the development of a system of P-index or the establishment of P-thresholds for our soils. However, we still have maps of soil and relief unsatisfactory and a system like P-index needs this information. So I think that initially the development of P-thresholds is a quick alternative to be used to regulate the use of manure and I'm working on it. Over time, with data collection by researchers, we can move to a system of P-index. However, even in countries or states that use this systems (P-thresholds or P-index) it is common to find high P concentration in waters. The main question is coming up here is: What is the best way to protect water bodies against P-transfer from soils? How to determine if a soil is environmentally safe or not to apply P? How do you handle it in your region?
Dear Luciano,
About half of the European countries have legislation regarding P application on agricultural soils. I have recently published a report on the various legislations in Europe: http://www.ilvo.vlaanderen.be/Portals/68/documents/Mediatheek/Phosphorus_legislation_Europe.pdf.
There are only a few countries that take the phosphorus state of the soil into account: in The Netherlands, Ireland, (Finland and Luxembourg: environmental programs) the application limit depends upon the soil P content. So no transport risks are taken into account. In Flanders (Northern part of Belgium) there is a reduced application limit for soils with a phosphate saturation degree above 35%. You can find the details in the report.
The best way to protect the water is an application limit depending upon the soil P content and the P loss risk. There is no magic formula for this, however. Restrictions depending upon the soil P content are already a good step forward, but the exact application limits should be well defined. Given the legacy phosphorus, water quality will only restore a few years or even decades after the restrictions...
Regards,
Fien Amery
Hi
In the UK we have the RB209 manual where the government provides recommendations on fertilizer use, including P: https://www.gov.uk/government/publications/fertiliser-manual-rb209
The recommendation help compliance with EU legislation in the EU Water Framework Directive: http://ec.europa.eu/environment/pubs/pdf/factsheets/water-framework-directive.pdf
regards
andrew
Cranfield Soil and AgriFood Institute.
It's not my area of expertise but I know that there is a region in the US (Chesapeake Bay, in the East Coast) with serious problems of water pollution because of high P and N (mostly coming from nutrient runoff from farms and concentrated animal feeding operations). There are many people from universities in the area (comprising several states) working on it. Please, find attach one document that summarize the situation. I'm sure you can find a lot more information if you search the web.
The legislation in Québec, Canada, considers the following four papers (soil texture and classification).
The Québec (Canada) law considers the following four papers (P/[Al+Fe] Mehlich3 ratio, soil texture and soil classification). The P/[Al+Fe] Mehlich3 ratio was related to total P (no more than 0.03 mg total P/L) in subsurface drainage water.
Yes, you can use biofertilizers containing phosphate dissolving bacteria. They work on the fixed di and tri-phosphates and make them available to plants. No need then to apply external phosphorus source, given that your soil contains fixed phosphates unavailable for plants.
Dear Luciano:
My study field deals with diagnosis of nutrient status of crops (forest species). Diagnosis may help determine what nutrient or nutrients a farmer should apply. If your area has P-rich soils, crop nutrient diagnosis should detect no phosphorus needs as well as those nutrients that might be limiting production. Nutrient diagnosis techniques such as DRIS, critical nutrient concentration or vector analysis, among others, help a lot to do this job.
Regards,
Dear Luciano,
About half of the European countries have legislation regarding P application on agricultural soils. I have recently published a report on the various legislations in Europe: http://www.ilvo.vlaanderen.be/Portals/68/documents/Mediatheek/Phosphorus_legislation_Europe.pdf.
There are only a few countries that take the phosphorus state of the soil into account: in The Netherlands, Ireland, (Finland and Luxembourg: environmental programs) the application limit depends upon the soil P content. So no transport risks are taken into account. In Flanders (Northern part of Belgium) there is a reduced application limit for soils with a phosphate saturation degree above 35%. You can find the details in the report.
The best way to protect the water is an application limit depending upon the soil P content and the P loss risk. There is no magic formula for this, however. Restrictions depending upon the soil P content are already a good step forward, but the exact application limits should be well defined. Given the legacy phosphorus, water quality will only restore a few years or even decades after the restrictions...
Regards,
Fien Amery
I think scientific approach is more economical to producers, sustainable and environmentally friendly than legislation. Crop response to phosphorus is limited by soil pH and P status in the soil. Unlike nitrogen, P is an immobile element in the soil. Thus, soil test based phosphorus calibration in relation to soil and crop type, and agro-ecological zone is the best approach for phosphorus fertilizer application.
The origin of the problem is the balance input / output. The limit will be a control, but the manure production will go on, cause is a important economic activity for your state. The way is the export of your nutrients excess to other regions. With technology, incentive, profitability and feasibility, it could be possible. In our soils in the humid tropics, highly leached and with low levels of nutrients, certainly make us a great demand.
As already written in Fien Amery’s answer above, in Finland most of the farms (95% of field area) are participating the national agri-environmental support program and getting a remarkable part of their income from it. According to the program, farmers have to take soil sample for P-analysis from their fields: at least a sample per 5 hectares in every 5th year. The maximum allowed P fertilizing depends on soil P-status and cultivated crop.
Although only 5% of fields are not included into the program and the program has started already in the 90’s, eutrophication is still problem (and agriculture is the main source of nutrients). Water quality in rivers and in coastal areas has not shown to be much improved. The changes are slow. In addition to regulated fertilization, other things are needed as well to decrease nutrient loadings. (Buffer zones? Others?)
[Currently valid Finnish maximum values for added P for different crops (in rows) and different P-status (in columns) are given in Table 21 and 22 (vegetables & berries) in page 26 in the guidance document, which is unfortunately not available in English: http://www.mavi.fi/fi/oppaat-ja-lomakkeet/viljelija/Documents/Opas%20ymp%C3%A4rist%C3%B6tuen%20ehtojen%20mukaiseen%20lannoitukseen%202007-2013.pdf . If soil P-status is high, no P-fertilization is allowed at all.]
A big problem is the confidence of sampling made by farmers. As many polluting industries do, they take samples from less contaminate (fertile) areas, to avoid possible problems with legislations. And how to control the rate of applications they make? I agree with Rodrigo Berni in that the best solution is make sense (profitable) to farmer not apply manures in excess, through the sale of manure concentrate/compost. The barrier to this is the low price the farmers receive for this kind of product in regions with large production of animals like western Santa Catarina state.
There is no legislation in India that regulates the P fertilizer use due to which soil test for P has shown as of moderate status in cultivated soils while two decades ago, the P deficiency in soils was maximum. The excess NPK complex fertilizer is more a rule than an exception in majority of irrigated soils due to intensive publicity of chemical fertilizer manufacturing companies and traders to boost their business with utter disregard to soil and water quality and attendant problems of environmental pollution. Unfortunately, soil test for P or for that matter for any nutrient is not mandatory to decide on need or otherwise fertilization for crops. Thanks to skyrocketing of chemical fertilizer prices which has eventually deterred farmers to opt for organic fertilization use such as composting, vermicomposting, green manuring, green leaf manuring, oil cakes etc. Legislation to promote need based and judicious use of chemical fertilizers and pesticdes, herbicides is imperative for any country if not the world to improve quality of natural resources and life of all organisms on Earth. Kudos to Fien, Katri and Evair for their significant and valuable contributions in this regard as to sensitize the other countries of the world, on genuine and urgent need for legislation on use of synthetic chemicals in farming.
I live in Cross River State in the southern part of Nigeria. Our soils in Calabar southern Cross River State are very sandy and strongly acidic as well. Currently, there are no officially known regulation on phosphorus limits. But from experience, a lot of farmers and even researchers apply phosphorus from rock phosphates, and this takes along time to disappear from the soil, making some parts of the Calabar soils over-laden with high phosphorus. Legislation of some chemical fertilizers is an imperative but not where food is insufficient. You may peruse through the attached article to see the level of P in Calabar soils.
Article Effect of Rice Husk Ash and Phosphorus on Some Properties of...
Hi Luciano,
In Germany nutrient balances are to be made. For phosphorus, are to create a nutrient balance for the nutrient uptake and nutrient input every 6 years and every 3 years for nitrogen. As the average in this 6 or 3 years the balance value does not exceed 20 kg / ha of phosphorus and for nitrogen 60 kg / ha.
Maximum input of fertilizer from animal origin (manure, slurry, dung etc) is 170 kg total nitrogen / ha per year.
One effective way is to minimize the Phosphorus balance sheet values at the field AND also at every part-field!
The P fertilization should be minimized and can be oriented / calculated at the withdrawal. At high soil nutrient stocks, the balance sheet value can be negative! An optimization of fertilization is to be made site-specific.
Spatial distribution of nutrients within a field see:
https://www.researchgate.net/publication/260502756_Part_Field_Management_Comparison_of_EC-value_soil_texture_nutrient_content_and_biomass_in_two_selected_fields
What is important to remember that a consultation for farmers is necessary.
In Germany, there is also an excessive nutrient input in some regions. This problem is also solved by a nutrient transport to other regions. The construction of new swine stables is very difficult in these regions. A condition for a new swine stables is the certification of sufficient arable area.
Best regards from Osnabrueck / Germany, Stefan
Conference Paper Part Field Management: Comparison of EC-value, soil texture,...
Look at the European soil and water framework directory and you will get lot's of information on that regard
In Colombia there is not a law that regulates the amount of application of fosoforo in crops. In the case of sugarcane is made, when required, according to the analysis of soil and crop requirement
May I suggest that you check on the following publication for a response to your question on "How to determine if a soil is environmentally safe or not to apply P?"
Soil Phosphorus Storage Capacity for Environmental Risk Assessment, Advances in Agriculture, vol. 2014, Article ID 723064, 9 pages, 2014. doi:10.1155/2014/723064
A related publication --
Soil phosphorus saturation ratio for risk assessment in land use systems. Front. Environ. Sci. 2:6. 2014. doi:10.3389/fenvs.2014.00006
Both the publications are open access publications and have been uploaded at ResearchGate.
Best regards.
Vimala
Lithuania has no general maximum phosphorus application rates or other P restrictions. Manures rates may not exceed 170kg/ha N, but such amount causes an excessive oversupply of P when pig/poultry manure applied.
The piggery waste can be mixed with vegetable waste and fed to earthworms after partial decomposition lasting over a month. This step would eventually reduce the P concentration by dilution effect. The product vermicompost, thus prepared may be applied to soils where crops such as cotton, coffee, peanut, maize, oats, wheat and other grain crops are grown as the grain crops have preferential absorption for phosphorus. This measure would reduce the problem of eutrophication. India where I live has no legislation to restrict chemical fertilizer use as such a step would weaken the chances of profiting the fertilizer industries.
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