The Plant nutrition courier newsletter publishes six times a year about plant nutrition related research. On this news page we give previews and we post plant nutrition related news that is beyond the scope of the newsletter but that still may be of interest.
Nitrogen fertiliser remains in soils and leaks towards groundwater for decades


Nitrogen fertiliser applied to crops lingers in the soil and leaks out as nitrate for decades towards groundwater. "Much longer than previously thought", scientists at the Université Pierre et Marie Currie in Paris (France) and at the University of Calgary say in a  study published this week in the Proceedings of the National Academy of Sciences of the United States of America . Thirty years after synthetic nitrogen (N) fertiliser had been applied to crops, about 15 per cent of the fertiliser N still remained in soil organic matter, the scientists found. After three decades, approximately 10 per cent of the fertiliser N had seeped through the soil towards the groundwater and will continue to leak in low amounts for at least another 50 years. According to the researchers, this long-term experiment is...

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Scientists unravel the secret of the legume


In small, bump-like nodules on roots in crops like soybeans and alfalfa, rhizobia bacteria produce the nitrogen that plants need to grow green and healthy. Scientists have wondered for years exactly how this mutually beneficial relationship works. A discovery by a team of University of Missouri researchers could be the first step toward helping crops use less nitrogen, benefitting both farmers' bottom lines and the environment. Gary Stacey, an investigator in the MU Bond Life Sciences Center and professor of plant sciences in the College of Agriculture, Food and Natural Resources, found that crops, such as corn (maize), are "confused" when confronted with invasive, but beneficial, bacteria known as rhizobia bacteria. When the bacteria interact correctly with a crop, the bacteria receive some food from the plant...

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Soil surfactant reduces common scab in potato


Spraying the appropriate surfactant over potato ridges just before emergence reduces common potato scab in dry years. Application of the right soil surfactant leads to a higher content of soil water in the ridges during periods of drought and that is unfavourable for the scab causing bacterium. Furthermore, in dry years a treatment with a soil surfactant can increase tuber yield significantly. So it appears from a two years spanning field experiment on a drought sensitive sandy soil of a Dutch experimental farm. Results of this research are published in the Potato nutrition courier , the supplement of the bimonthly Plant nutrition courier . The Plant nutrition courier is a digital newsletter about research on plant nutrition and fertilisers. In a feature about soil surfactants this digital newsletter also reports about...

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Uitvloeier beperkt schade door schurft in aardappel


Aardappelen op zandgrond hebben in een droog jaar minder last van gewone schurft, als de ruggen kort voor opkomst met de juiste uitvloeier worden bespoten. Bovendien kan grondbehandeling met een uitvloeier in droge jaren de knolopbrengst flink verhogen. Veldproeven op droogtegevoelige gronden hebben deze eigenschappen van zogenaamde soil surfactants aan het licht gebracht. De resultaten van de proeven zijn gepubliceerd in de Potato nutrition courier , de vaste bijlage van de tweemaandelijkse Plant nutrition courier . De Plant nutrition courier is een Engelstalige nieuwsbrief over onderzoek op het gebied van bemesting en meststoffen. Het hoofdartikel over bodemtoediening van uitvloeiers besteedt verder aandacht aan het effect van deze hulpstoffen op de knolsortering bij aardappelen, de vochtvoorziening van gewassen, de...

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Diamond catalyst shows promise in breaching age-old barrier


Nitrogen is an ubiquitous small-molecule gas that can be transformed into the agricultural fertiliser ammonia. Plants perform the chemical reduction of atmospheric nitrogen to ammonia as a matter of course, but for humans to do that in an industrial setting requires subjecting nitrogen to massive amounts of energy under high pressure. "The current process for reducing nitrogen to ammonia is done under extreme conditions", says Robert J. Hamers with reference to the so-called Haber-Bosch process. "There is an enormous barrier you have to overcome to get your final product". Hamers is professor of chemistry at the University of Wisconsin-Madison . Breaching that barrier more efficiently and reducing the huge amounts of energy used to convert nitrogen to ammonia - by some estimates, 2 percent...

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Potato nutrition has a face


Potato is the fourth food crop in the world, after maize (corn), rice and wheat. In terms of human consumption, potato is even the third most important food crop. Worldwide researchers examine new and old methods to improve nitrogen and phosphorus nutrition of this relatively shallow rooting crop. Nutrition largely influences tuber amount, size and quality. As from the February 2013 issue Plant nutrition courier therefore has a Potato nutrition courier supplement, which starts with a series of articles about innovative fertilisation approaches. Recent potato nutrition literature that is listed in the Publications about plant nutrition research, is also listed in a separate section in the Potato nutrition courier supplement to help the many potato-interested readers find their stuff more easily. Source: Plant nutrition...

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Coating seed potatoes with phosphorus improves early growth


Spraying seed potatoes before planting with phosphate improves early growth of the potato crop. So it appears from preliminary field trials conducted on Dutch soils low in phosphorus. The experimental phosphate formulation is atomized at a dose of approximately 1 kg phosphate (P 2 O 5 ) per hectare. With this treatment, potato growers can save around 10 kg phosphate per hectare. Results of the preliminary trials confirm the well-known advantage of seed tubers rich in phosphorus. This year the experiments will be continued on a larger scale. Soaking Earlier Indian potato experts have found that soaking physiologically active seed tubers in a monoammonium phosphate (MAP) solution leads to a substantial increase in phosphorus concentration in the tubers. Seed tuber soaking in diammonium phosphate (DAP) or superphosphate also...

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Pootgoed gebaat bij extra fosfaat


Aardappelen met een grote fosfaatreserve groeien sneller dan fosfaatarme poters. Een hoog fosfaatgehalte in de knollen biedt bovendien kansen om op de fosfaatbemesting te besparen, zo blijkt uit een bureaustudie die binnenkort in de Plant nutrition courier wordt gepubliceerd. Aardappelen met fosfaat voorbehandelen verhoogt het gehalte van deze voedingsstof in de knollen. De poters – mits uit kiemrust – nemen het fosfaat op en gebruiken de voedingsstof voor een snelle weggroei. In veldproeven van het Central Potato Research Institute (India) komt het dompelen van pootgoed in monoammoniumfosfaat (MAP) als beste uit de bus, maar voorbehandelen met diammoniumfosfaat (DAP) en superfosfaat (SSP) geeft ook een significante meeropbrengst. De onderzoeksresultaten laten zien dat voorbehandeling met fosfaat een besparing op de...

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Selenium can help tackle nutritional deficiency in Malawi


Enriching crops by adding selenium to fertilisers could potentially help to reduce disease and premature death in the African country of Malawi, University of Nottingham researchers say. An international study led by academics at this British university has shown that dietary deficiency of the mineral selenium — which plays a vital role in keeping the immune system healthy and fighting illness — is likely to be endemic among the Malawi population. They found that most Malawi soils cannot supply enough selenium for adequate human nutrition (click here for map ). In a paper published in the journal Scientific Reports, they call for further investigation into the benefits and costs of using selenium-enriched fertilisers and other strategies to boost levels within the country’s food. Read more Source: The...

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Citrus disease Huanglongbing linked to phosphorus starvation


American and Chinese researchers have found that citrus trees attacked by the Huanglongbing disease (HLB) are suffering from severe phosphorus deficiency. Application of phosphorus solutions to the diseased trees significantly alleviates HLB symptoms and thus improves fruit yield in a three-year field trial in southwest Florida. Phosphorus solutions were applied to HLB-positive sweet orange trees in a field trial three times per year for more than three years. After two years of treatment, the diseased trees displayed significantly reduced HLB symptoms. Fruit yield increased approximately two-fold compared with control plants. The researchers say that application of phosphorus solutions did not cure the trees, but this treatment may help the diseased trees to look healthier and improve fruit yield. The citrus disease Huanglongbing,...

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Labile soil organic matter predicts maize performance


Carbon mineralization is a better predictor of maize agronomic performance than pre-sidress nitrate test and leaf chlorophyll. So it appears from a study conducted by Steve Culman , a researcher at the W.K. Kellogg Biological Station that is published online in Agronomy Journal (see abstract ). With colleagues from Michigan State University he characterizes simple, cheap measurements of labile soil organic matter that could predict the performance of maize (corn) crops and help farmers optimize their cropping systems. They found that the size of the labile fraction of soil organic matter can be an important predictor of maize agronomic performance. But the tests used up to this point to measure those pools, such as microbial biomass and particulate organic matter, were labor intensive and expensive. Culman decided to use other...

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Studies show biosolids can boost soil phosphorus levels for years


Treated wastewater solids called biosolids are sometimes used by farmers to boost soil nutrient levels. Now research by U.S. Department of Agriculture (USDA) agronomist Eton Codling provides new information about how long those plant nutrients remain after biosolids have been applied to the soil. Codling works at the USDA ARS Environmental Management and Byproduct Utilization Laboratory in Beltsville. Biosolids used in agricultural production have been processed to kill pathogens, and their use is strictly regulated to ensure that the materials don't harm the environment, human health or animal health. Farmers who follow pre- and post-application management regulations can obtain permits to apply biosolids to fields where food and feed crops are grown. Codling measured mineral levels in three different soils...

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Dietary shifts driving up phosphorus use


Dietary changes since the early 1960s have fueled a sharp increase in the amount of mined phosphorus used to produce the food consumed by the average person over the course of a year, according to a new study led by researchers at McGill University. Between 1961 and 2007, rising meat consumption and total calorie intake underpinned a 38% increase in the world's per capita "phosphorus footprint," the researchers conclude in a paper published online in Environmental Research Letters . Read more Source: McGill University

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Bacterial residues significantly contribute to soil fertility


Remains of dead bacteria have far greater meaning for soils than previously assumed. Around 40 per cent of the microbial biomass is converted to organic soil components, a German-Norwegian team of researchers writes in the professional journal Biogeochemistry. Until now it was assumed that the organic components of the soil were comprised mostly of decomposed plant material which is directly converted to humic substances. In a laboratory experiment and in field testing the researchers have now refuted this thesis. Evidently the easily biologically degradable plant material is initially converted to microbial biomass which then provides the source material to soil organic matter. Read more Source: Helmholtz Centre for Environmental Research 

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Researchers develop novel method to recover phosphorus from pulp mill wastewater


Researchers at Aalto University (Finland) have developed a simple method for reducing the amount of phosphorus in the wastewater of a pulp mill. The method is called simultaneous precipitation using iron sulphate . A separate treatment stage is not required, as the precipitation takes place simultaneously with the actual biological wastewater treatment. Iron sulphate is added to the wastewater prior to the biological wastewater treatment process, and the phosphorus dissolved into the water is precipitated with the biomass at the treatment plant. Finally, the phosphorus is removed from the plant with the sludge. In Finland, sludge is generally burned, in which case the phosphorus would end up in the ashes and would thus be reusable in the form of fertilizers, for example. Read more Source: Aalto University

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Octrooien schermen nieuwe bemestingsmethoden af


Akkerbouwers moeten bedacht zijn op octrooibescherming als ze buitenlandse teeltmethoden overnemen. Voor Nederland nieuwe teeltmaatregelen kunnen namelijk al zijn afgeschermd, zo blijkt uit een octrooiscan van de Plant nutrition courier . De Engelstalige nieuwsbrief deed de scan in het kader van een literatuuronderzoek naar een nieuwe methode voor het toedienen van fosfaat aan aardappelen en andere akkerbouwgewassen. Plant nutrition courier kwam bij dit onderzoek octrooien op het spoor die een vrije toepassing van dergelijke technieken willen belemmeren. Het gaat bijvoorbeeld om octrooien voor het coaten van zaaizaad en pootgoed met fosfaathoudende meststoffen en het toedienen van hulpstoffen om de opname van voedingsstoffen te verbeteren. Het octrooieren van teeltmaatregelen lijkt vooral een Aziatische en Oost-Europese...

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Recycling ammonia emissions as fertiliser


Capturing and recycling ammonia from livestock waste is possible using a process developed by U.S. Department of Agriculture (USDA) researchers. This invention could help streamline on-farm nitrogen management by allowing farmers to reduce potentially harmful ammonia emissions and concentrate nitrogen in a liquid product to sell as fertiliser. The system uses gas-permeable membranes that are similar to materials already used in waterproof outdoor gear and biomedical devices. Using these materials, the scientists recorded an average removal rate from 45 to 153 milligrams of ammonia per litre per day when manure ammonia concentrations ranged from 138 to 302 milligrams of ammonia per litre. When manure acidity decreases, ammonia recovery increases. USDA filed for a patent on this invention ( US20110229403 ). Read more...

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New class of iron chelates


Spanish researchers have developed novel iron chelates with interesting agronomical properties. So reports Plant nutrition courier in the yesterday published August 2012 issue . The so-called aquo -complexes are structurally related to Fe 3+ - o , o -EDDHA and can directly be reduced by the ferric chelate reductase enzyme. This enzymatic redox reaction is necessary for root uptake of iron. According to the Spanish scientists the research on the promising iron chelates will be continued. The aquo -complexes reminds one of Fe 3+ - o , p -EDDHA. Compared to Fe 3+ - o , o -EDDHA, this isomer is less stable, but is faster assimilated by plant roots. The Spanish researchers attribute these properties to the para-position of one of the hydroxy groups of the o , p -EDDHA isomer. Source: Plant nutrition courier

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Plant and soil analysis with handheld XRF spectrometer


Current generation handheld X-ray fluorescence (XRF) analysers are applicable for rapid routine and non-destructive analysis of total element concentrations in ground plant tissue samples. So it appears from an exploratory examination conducted by researchers from the University of New England School of Environmental and Rural Science. With this experiment they were able to quantitatively determine 11 elements in samples of three test crops. With a fourth test crop (wheat) they were less successful; the reason for the disappointing results is not yet clear. British researchers confirm the usefulness of portable XRF spectrometers; they successfully analysed phosphorus and silicon simultaneously in samples of 0.1 g dried and ground plant material. From another exploratory study with Vertisol soil samples the Australian researchers...

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Feed fermentation enhances phosphorus digestion, saves on phytate


University of Illinois researchers recently found that pigs digest the phosphorous in fermented soybean meal (FSBM) better than the phosphorus in conventional soybean meal. "Most of the P in soybean meal is bound to phytate, so it's not available to pigs", explained animal sciences professor Hans Stein. Previous research by Stein's group found that pigs digest the phosphorous in fermented corn more easily than that in non-fermented corn. "Fermentation releases phosphorus from the phytate molecule", Stein said. In this study, Stein and his team looked at whether FSBM offered the same advantage. They observed that the standardized, total-tract digestibility of phosphorus in FSBM is 65.5 percent, compared with 46.1 percent in conventional soybean meal. When the enzyme phytase was added to the diets, the...

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