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Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus

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A special issue of Agronomy (ISSN 2073-4395). This special issue belongs to the section "Farming Sustainability".

Deadline for manuscript submissions: closed (30 September 2021) | Viewed by 44059

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Special Issue Editor

Dr. Arno Rosemarin

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Guest Editor

Stockholm Environment Institute, Stockholm, Sweden
Interests: phosphorus use efficiency; phytase and phytate in feed; phosphorus/nitrogen ratios; manure management; soil nutrient dynamics; runoff and eutrophication management; feed-animal-manure nutrient mass balance; managing phosphorus surpluses in agriculture; farm-based economics; reuse of phosphorus from agro-wastes and sewage sludge; governance of phosphorus and nitrogen use in agriculture

Special Issue Information

Dear colleague,

The need for increased sustainable use of phosphorus has come into focus over the past decade with the realization that extensive, relatively cheap commercial reserves of phosphate rock are presently limited to only a handful of countries. Intensive animal farms such as dairy, pig and poultry can experience manure management and reuse challenges, resulting in overdosing croplands with more phosphorus than what target crops require. This results in phosphorus enrichment of the upper soil layers and eventually in losses to the surrounding catchment areas through runoff. For sensitive areas, these surpluses can result in the long-term eutrophication of water bodies. Due to site variability, regulations to match the manure phosphorus additions to crop offtake requirements are generally lacking around the world. Additionally, attempts at farmgate balancing and phosphorus indices have proven difficult over recent decades in North America and Europe. The general trend is that manure is spread on the basis of its nitrogen content in relation to crop requirements. Stored manure can lose its nitrogen content through ammonia and nitrate losses, resulting in a lowering of N/P content compared to fresh manure. This can result in the overdosing and wasting of phosphorus on croplands.

Solving this problem and achieving a more sustainable approach to phosphorus use in agriculture requires a re-examination of the entire system and fate of phosphorus in the soil, feedcrops, feed regimes, animal densities, manure treatment, storage and spreading, runoff potential and sensitivity of catchment areas.

This Special Issue will focus on various aspects of this system. Papers for this Special Issue are invited to include aspects of either environmental and/or economic sustainable use of phosphorus in agriculture. The following list of topics with global reach are relevant to this issue:

Soil–crop systems: phosphorus fertilizer norms and use efficiency in common crops; phosphorus offtake levels for common crops; nitrogen/phosphorus ratio fertilizer requirements in common crops; plant availability of phosphorus in manures and various manure-based fertilizers

Feed–animal–manure–crop systems: feed–animal–manure phosphorus mass balance and efficiencies in intensive dairy, pig and poultry farms; feed phosphorus retention and digestibility in farm animals taking into account phytase and phytate levels in feed, feed composition and regimes, pelletization or water content; manure management and treatment to retain nitrogen/phosphorus ratios to better match crop requirements and reduce surplus applications of phosphorus on croplands; farmgate balancing of phosphorus in order to minimize surpluses; cycling of phosphorus in animal farms to reduce surpluses; role of livestock densities in reaching sustainable phosphorus use in animal farms

Runoff and erosion: use of phosphorus indices to help to manage fertilizer/manure/sludge applications to cropland, assess soil phosphorus levels, determine soil erosion risk and potential losses of phosphorus from croplands to water courses; management of agricultural sources of phosphorus in calibrated watersheds using fate and impact models; soil mapping of surplus levels of phosphorus related to agriculture practices; precipitation and runoff models to determine the risk of soil erosion and runoff resulting in phosphorus losses from croplands to water courses; runoff and soil erosion management techniques to prevent phosphorus loading to water courses; impacts of excess phosphorus runoff in receiving waters

Policies and governance: policies, regulations and governance of phosphorus in agriculture in order to reduce phosphorus surpluses and losses to drainage basins; governance and regulation of both phosphorus and nitrogen use in agriculture; regulations and national norms for phosphorus in the spreading of manure on croplands; inventory of agriculture activities and practices that may lead to phosphorus soil surpluses; regulations to manage phosphorus surpluses in agriculture (crop and animal farms); nutrient emissions trading within and between neighbouring drainage basins to help to achieve nutrient sustainability within agriculture

Economics: farm-based economics of phosphorus use in crop and animal farms; economics of manure treatment (e.g., storage, acidification, dewatering and drying) in order to enable transportation between intensive animal farms and feed croplands; economics of reuse in agriculture of phosphorus originating from agro-wastes and municipal sewage sludge; economic impacts of regulating phosphorus in agriculture to increase use efficiency and reduce surpluses and losses to drainage basins; economic impacts of including phosphorus balancing in agriculture

Ecotechnologies: new approaches to fertilizing crops to increase use efficiency and decrease nutrient surpluses and losses; novel farming practices that increase phosphorus use efficiency; production of fertilizers from agro-waste and municipal solid and liquid waste in order to close the loop on phosphorus and reduce the use of virgin mineral phosphorus rock sources.

Dr. Arno Rosemarin
Guest Editor

Manuscript Submission Information

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

phosphorus in soil–crop systems
phosphorus in feed–animal–manure–crop systems
phosphorus in agriculture runoff and erosion
phosphorus in agriculture policies and governance
phosphorus in agriculture economics
Phosphorus in agriculture ecotechnologies

Published Papers (12 papers)

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Research

Jump to: Review

16 pages, 972 KiB

Open AccessArticle

Resource Recovery from Synthetic Nitrified Urine in the Hydroponic Cultivation of Lettuce (Lactuca sativa Var. capitata L.)

by Anna Jurga, Kamil Janiak, Anna Wizimirska, Piotr Chochura, Stanisław Miodoński, Mateusz Muszyński-Huhajło, Krzysztof Ratkiewicz, Bartosz Zięba, Marta Czaplicka-Pędzich, Tomasz Pilawka and Daria Podstawczyk

Agronomy 2021, 11(11), 2242; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11112242 - 05 Nov 2021

Cited by 6 | Viewed by 3165

Abstract

The application of hydroponic cultivation fertilized with biologically nitrified synthetic urine can produce nitrate-rich fertilizer for lettuce (Lactuca sativa var. capitata L.). The mounting water crisis and depletion of natural resources makes nitrogen recovery from human urine a practical option. Nitrified urine can be used in indoor vertical hydroponic cultivation and is characterized by a high degree of element recovery. Because of its high ammonium content, hydrolyzed fresh urine may be toxic. A nitrification sequencing batch reactor with suspended activated sludge biomass ensured urine stabilization and biological conversion into nitrate-rich fertilizer. The diluted nitrate-rich fertilizer was then supplied for soilless cultivation. The results show that diluted nitrified urine is an excellent source of bioavailable nitrogen and phosphorus and, with proper enrichment with microelements, could replace commercial fertilizers in hydroponic systems. The yield and quality parameters of lettuce cultivated with enriched urine were comparable to those obtained with a commercial fertilizer. The mass balance calculation showed that industry-scale lettuce production can be based on urine fertilizer collected from a few hundred people for a single unit. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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27 pages, 4596 KiB

Open AccessArticle

Phosphorus Flows, Surpluses, and N/P Agronomic Balancing When Using Manure from Pig and Poultry Farms

by Arno Rosemarin, Nelson Ekane and Kim Andersson

Agronomy 2021, 11(11), 2228; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11112228 - 03 Nov 2021

Cited by 7 | Viewed by 3008

Abstract

The pig and poultry industries continue to grow across the world and together they provide the majority of meat consumed. The European Union (EU) in particular has the highest global relative meat production by monogastrics (i.e., pig and poultry). The fate of phosphorus (P) in pig and poultry farming was studied, accounting for P content in feed, animals, manure, soil, and runoff. P input from manure, and P offtake in crops receiving manure, were plotted against each other to arrive at “safe” P loading rates, in order to minimize soil P surpluses along the lines of the EU Nitrogen Expert Panel in their work with nitrogen (N). However, it was observed that it is the N/P ratio and the background soil P levels that determine whether a certain manure will end up producing surplus levels of soil P. Critical N/P weight ratios were derived over different crop P offtake rates when applying stored manure to croplands. At spreading rates of 170 and 250 kgN/ha/year and a crop P offtake of 15 or 30 kgP/ha/year, stored pig and chicken manure result in soil P surpluses. An important factor in determining effective N/P ratios is the plant availability of N in stored manure, which runs at around 47%, estimated from previously published results. The minimization of N losses to the atmosphere and to groundwater in housing, storage, and spreading of manure has a major impact on the N/P weight ratio of the manure that ends up on fields. In most cases, half of the ex-animal N content has been lost in stored or degraded manure, with N/P weight ratios running at two and less. Following only the EU Nitrates Directive, which allows for a maximum of 170 kgN/ha/year in NVZs (Nitrate Vulnerable Zones), will often result in soil P surpluses leading to runoff losses to adjacent water bodies. Therefore, for the pig and poultry industries to continue thriving, measures are required to better manage manure, including improved storage and spreading techniques, acidification, separation, struvite extraction and ammonia stripping of pig slurry, and drying and pelleting of poultry litter. This way, excess manure and derived biofertilizers from animal farms can find their way back into the commercial market, instead of ending up as legacy P in watersheds and coastal zones. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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13 pages, 1278 KiB

Open AccessArticle

Fertilization with Municipal Wastewater Phosphorus Adsorbed to Alginate Beads: Results from a Pot Experiment with Italian Ryegrass

by Krzysztof Pawelec, Hanna Siwek, Teodor Kitczak and Małgorzata Włodarczyk

Agronomy 2021, 11(11), 2142; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11112142 - 26 Oct 2021

Cited by 1 | Viewed by 1423

Abstract

The global increase in the demand for fertilizers and thus phosphorus (P) contributes to the depletion of P reserves and the need to recycle this element. This paper presents the results of a pilot-scale experiment on the possibility of using a fertilizer preparation containing alginate, Fe and P (AFP) obtained in the process of P adsorption from sludge water on a hydrogel alginate adsorbent cross-linked with iron (III) ions. The influence of AFP on the growth of a model plant of the Italian ryegrass (Lolium perenne cv. Turtetra) was examined in comparison with differentiated mineral fertilization (MF) under the conditions of a pot experiment. The two fertilizers produced similar crop yields of the tested plant and had similar plant and soil macro- and micro-elements, except for the content of Fe and Cu in ryegrass, which was significantly higher with AFP fertilization. Further research on the use of the proposed sorbent for large-scale P recycling in an uncontrolled field environment should include acceptable limits for multivalent metal concentrations in wastewater, the mechanical/thermal stability, and the effectiveness of AFP under field conditions and a cost competitiveness. AFP has the potential to compete with mineral fertilizers for P fertilization, and this technology is in line with the EU circular economy vision. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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21 pages, 1697 KiB

Open AccessArticle

Measuring On-Farm Phosphorus Fertiliser Use—Lessons Learned from Surveying Data of Five Regions in Northern Germany

by Paul Winklhofer, Sabine Andert, Silke Hüttel and Bärbel Gerowitt

Agronomy 2021, 11(11), 2123; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11112123 - 22 Oct 2021

Cited by 1 | Viewed by 2113

Abstract

Phosphorus (P) is essential for agriculture; however, local P surpluses can have adverse environmental effects, such as eutrophication. Optimal P fertiliser use, therefore, means balancing these effects. Although P fluxes from soil to plants are key research areas, little is known about on-farm use of P fertilisers. As, typically, not all fields or crops are treated with P annually, the transferability of measurements for other nutrients, such as nitrogen, appears limited. This study aims to close this knowledge gap. On-farm P use was described using the farm records of 50 farms in five regions of northern Germany for the period of 2010 to 2018. All sources for P fertilisation were taken into account as either P mineral, P organic or P total. Two indicators for on-farm P use were suggested: frequency, which gives the percentage of the treated area, and amount, which gives the quantity used per ha of the treated area. The frequency for P total ranged from 55.9% to 93.1% of the total farm area being fertilised. Amounts between 24.8 and 41.6 kg ha⁻¹ P total were applied on the treated area of the farm. The results supported the separation of the quantity and frequency in on-farm P use. No decrease in P use was found during the period investigated. Using mixed models, the results further show that explanatory variables, including the farm characteristics and crop choice, explain the substantial variations in P use. It is recommended for the example of Germany to establish an official digital database for P fertilisers that can be updated professionally and is mandatory for all documentation on P use. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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12 pages, 618 KiB

Open AccessArticle

Modeling of Phosphorus Nutrition to Obtain Maximum Yield, High P Use Efficiency and Low P-Loss Risk for Wheat Grown in Sandy Calcareous Soils

by Zhanyao Hu, Zheli Ding, Hatim M. Al-Yasi, Esmat F. Ali, Mamdouh A. Eissa, Salah F. Abou-Elwafa, Mohammed Abdelaziz Sayed, Mohamed Tharwat Said, Alaa A. Said, Khaled A. M. Ibrahim and Alhosein Hamada

Agronomy 2021, 11(10), 1950; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11101950 - 28 Sep 2021

Cited by 6 | Viewed by 2195

Abstract

Fertilization with high levels of phosphorus increases the risk of environmental pollution. Identification of critical values of P in soil (SOP) and in plant tissues (PiP) is essential for achieving the maximum wheat yield without P loss. The critical value is the value of P which gives the optimum yield; the response of crop yield to P fertilization above this value is not predictable or nil. Here, a 4-year field experiment was conducted to identify the SOP and PiP for achieving maximum yield of bread wheat using 11 rates of P fertilization (0, 15, 30, 45, 60, 75, 90, 105, 120, 135, and 150 kg P₂O₅ ha⁻¹). The linear–linear and Mitscherlich exponential models were employed to estimate the PiP and SOP. The degree of phosphorus saturation (DPS) was used to assess the potential environmental risk; furthermore, phosphorus use efficiency (PUE) was also calculated under the studied fertilization levels. Phosphorus in soil and wheat plant was affected by the application rates and growing seasons. Increasing P fertilization rates led to gradual increases in soil and plant P. The SOP ranged between 21 and 32 mg kg⁻¹, while the PiP ranged between 6.40 and 7.49 g kg⁻¹. The critical values of P calculated from the Mitscherlich exponential models were 20% higher than those calculated from the linear–linear models. Adding levels of P fertilization ≥90 kg P₂O₅ ha⁻¹ leads to higher potentials of P runoff and leaching, in addition, PUE decreased sharply under high P fertilization levels. The response of wheat yield to P fertilization in sandy calcareous soil is predictable below Olsen P values of 21 mg kg⁻¹. Identification of critical P values for wheat production is of great importance to help policy makers improve P use efficiency and attain optimum wheat yield under eco-friendly environmental conditions by eliminating the accumulation of excess P fertilizers in soil and water. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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13 pages, 2910 KiB

Open AccessArticle

Can Long-Term Experiments Predict Real Field N and P Balance and System Sustainability? Results from Maize, Winter Wheat, and Soybean Trials Using Mineral and Organic Fertilisers

by Ilaria Piccoli, Felice Sartori, Riccardo Polese, Maurizio Borin and Antonio Berti

Agronomy 2021, 11(8), 1472; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11081472 - 24 Jul 2021

Cited by 8 | Viewed by 1989

Abstract

Agri-environmental indicators such as nutrient balance may play a key role in soil and water quality monitoring, although short-term experiments might be unable to capture the sustainability of cropping systems. Therefore, the objectives of this study are: (i) to evaluate the reliability of long-term experimental N and P balance estimates to predict real field (RF) (i.e., short-term transitory) conditions; and (ii) to compare the sustainability of short- and long-term experiments. The LTE-based predictions showed that crops are generally over-fertilised in RF conditions, particularly maize. Nutrient balance predictions based on the LTE data tended to be more optimistic than those observed under RF conditions, which are often characterised by lower outputs; in particular, 13, 44, and 47% lower yields were observed for winter wheat, maize, and soybean, respectively, under organic management. The graphical evaluation of N and P use efficiency demonstrated the benefit of adopting crop rotation practices and the risk of nutrient loss when liquid organic fertiliser was applied on a long-term basis. In conclusion, LTE predictions may depend upon specific RF conditions, representing potential N and P use efficiencies that, in RF, may be reduced by crop yield-limiting factors and the specific implemented crop sequence. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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26 pages, 2955 KiB

Open AccessArticle

Urban Organic Waste for Urban Farming: Growing Lettuce Using Vermicompost and Thermophilic Compost

by Corinna Schröder, Franziska Häfner, Oliver Christopher Larsen and Ariane Krause

Agronomy 2021, 11(6), 1175; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11061175 - 09 Jun 2021

Cited by 15 | Viewed by 6074

Abstract

A transformation towards sustainable food production requires improved circular nutrient management. Urban organic waste contains relevant nutrients and organic matter, yet only 4% of global urban nitrogen (N) and phosphorus (P) sources are presently recycled. One recycling approach is the composting of urban wastes for urban horticulture. We characterized compost from various urban waste fractions and assessed their fertilizer value in a pot trial with lettuce plants. Seven treatments were investigated: food waste vermicompost with coir and paperboard bedding material, thermophilic compost from green waste and human feces, two references with mineral fertilization and a sand control. The lettuce yield and total uptake of P, potassium (K), calcium (Ca), and magnesium (Mg) were highest in plants grown in coir-based vermicompost. The fecal compost led to the highest shoot P and K content, but the shoot uptake of Ca and Mg were lower than in the other treatments. All composts required additional N for lettuce growth. In conclusion, urban waste-derived vermicompost and fecal compost demonstrate a high delivery rate of plant-available Ca, Mg, P, and K. Research is needed on macronutrient availability and alternative N sources for the substitution of synthetic fertilization. These findings support the production of urban waste composts, furthering efforts in nutrient recycling. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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18 pages, 1488 KiB

Open AccessEditor’s ChoiceArticle

Cycling Phosphorus and Nitrogen through Cropping Systems in an Intensive Dairy Production Region

by April B. Leytem, Paula Williams, Shan Zuidema, Audrey Martinez, Yen Leng Chong, Alyssa Vincent, Aaron Vincent, Daniel Cronan, Andrew Kliskey, J. D. Wulfhorst, Lilian Alessa and David Bjorneberg

Agronomy 2021, 11(5), 1005; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11051005 - 19 May 2021

Cited by 14 | Viewed by 3225

Abstract

As pressure on the dairy industry to reduce its environmental impact increases, efficient recycling of manure nutrients through local cropping systems becomes crucial. The aim of this study was to calculate annual nitrogen (N) and phosphorus (P) budgets in six counties located in the Magic Valley, Idaho and estimate what distance manure would need to be transported to be in balance with crop nutrient demand given current dairy cattle populations and cropping systems. Our analysis suggests that crop N needs will not be met solely by manure, and synthetic fertilizer will need to be applied. However, to balance P with crop production, manure would need to be transported a minimum of 12.9 km from dairies and would have to replace synthetic fertilizer P on 91% of regional cropland. Education of producers and technical specialists would be necessary to improve the management of manure use in regional cropping systems. Technical solutions such as alternative diets for cattle and nutrient capture from manure streams will also likely be necessary to bring regional P into balance to protect environmental quality and improve the sustainability of the regional dairy industry. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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18 pages, 3503 KiB

Open AccessArticle

New Fertilizer Strategies Combining Manure and Urea for Improved Rice Growth in Mozambique

by Fátima Ismael, Alexis Ndayiragije and David Fangueiro

Agronomy 2021, 11(4), 783; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11040783 - 16 Apr 2021

Cited by 13 | Viewed by 4965

Abstract

The cost of chemical fertilizers is increasing and becoming unaffordable for smallholders in Africa. The present study aimed to assess the impact of combined fertilization strategies using urea and animal manure (beef cattle manure and poultry litter manure) on rice yield and nutrient uptake. For this, a field experiment was carried out on a loam sandy soil in the Chókwè Irrigation Scheme. We set seven treatments in a Randomized Complete Block Design (RCBD), namely: T0: no fertilizer, T1: 100% urea, T2: 100% beef cattle manure, T3: 100% poultry litter, T4: 50% urea + 50% beef cattle manure, T5: 50% urea + 50% poultry litter and T6: 40% urea + 30% beef cattle manure + 30% poultry litter, replicated four times each. All treatments, except T0, received an amount of nitrogen (N) equivalent to 100 kgN·ha⁻¹. Results revealed that the highest yield grain (425 g·m⁻²), plant height (115 cm), number of tillers (18) and thousand-grain weight (34g) were observed in treatments combining urea with manure (T4, T5 and T6) indicating that N supply in the mixture (urea + manure) is more efficient than in isolated applications of N (T1, T2 and T3). The data obtained in this study suggest that a combination of fertilizers (T6) lead to competitive yields and is thus recommended for best soil management practices. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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11 pages, 262 KiB

Open AccessEditor’s ChoiceArticle

Use of Biochar-Compost for Phosphorus Availability to Maize in a Concretionary Ferric Lixisol in Northern GHANA

by Nasirudeen Sulemana, Eric K. Nartey, Mark K. Abekoe, Thomas A. Adjadeh and Daniel A. Darko

Agronomy 2021, 11(2), 359; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11020359 - 17 Feb 2021

Cited by 10 | Viewed by 3900

Abstract

A pot experiment was conducted to investigate the effect of biochar-compost on availability of P for maize cultivation in a concretionary Lixisol of northern Ghana and residual soil characteristics thereof. Sawdust biochar was co-composted with kitchen waste and cow dung in various proportions. Four biochar-composts were selected based on their superior carbon and available P content, lower pH, and electrical conductivity (EC). These were amended to attain the standard phosphorus requirement (SPR) and half the SPR of the Lixisol. Triple superphosphate and (NH₄)₂ SO₄ were, respectively, applied as inorganic fertilizer to meet the SPR and the average total nitrogen of the selected biochar-compost treatments. A control without any soil amendment was included. Maize was grown to tasseling (eight weeks) and shoot dry matter and P uptake determined. A 2.71 to 3.71-fold increase in P uptake led to a 1.51 to 2.33-fold increase in shoot dry matter in biochar-compost-amended soils over the control. Residual soil C, pH, and total and available P in the biochar-compost-amended soils were enhanced. Biochar-composts at half the SPR level produced maize with higher shoot dry matter than the equivalent inorganic amendment at full SPR. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

24 pages, 3082 KiB

Open AccessEditor’s ChoiceArticle

Productive and Environmental Consequences of Sixteen Years of Unbalanced Fertilization with Nitrogen and Phosphorus—Trials in Poland with Oilseed Rape, Wheat, Maize and Barley

by Agnieszka Rutkowska and Piotr Skowron

Agronomy 2020, 10(11), 1747; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy10111747 - 10 Nov 2020

Cited by 5 | Viewed by 2528

Abstract

Two factorial field experiments were carried out between 2003 and 2018 in the Experimental Stations in Eastern and Western Poland using four crop rotations with winter oilseed rape, winter wheat, maize and spring barley. The initial value of phosphorus (P) in Grabów soil was 69.8 mg P·kg⁻¹ soil and in Baborówko soil it was 111.3 mg P·kg⁻¹ soil (Egner-Riehm Double-Lactate DL). P fertilizer was added annually at 39 kg P·ha⁻¹ under winter oilseed rape, 35 kg P·ha⁻¹ under maize and 31 kg P·ha⁻¹ under wheat and barley using superphosphate and nitrogen (N), which was added at five levels (30–250 kg N·ha⁻¹) per year as ammonium nitrate in addition to controls with no added fertilizer. Through the several years of the experiment, P fertilizer had no effect on crop N use efficiency (NUE) nor crop productivity. There was significant soil P mining particularly in the high-N fertilizer trials causing a reduction in the content of available soil P by up to 35%. This work recommends that, based on soil P analysis, P fertilizer should not be added to high-P soils. This practice may continue uninterrupted for several years (16 in this case) until the excess soil P has been reduced. This mechanism of removal of “legacy” P from soil has major implications in reducing runoff P into the Baltic Sea drainage area and other water bodies. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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Review

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25 pages, 11030 KiB

Open AccessEditor’s ChoiceReview

Review of Two Mechanical Separation Technologies for the Sustainable Management of Agricultural Phosphorus in Nutrient-Vulnerable Zones

by Gary A. Lyons, Ashley Cathcart, J. Peter Frost, Michael Wills, Christopher Johnston, Rachael Ramsey and Beatrice Smyth

Agronomy 2021, 11(5), 836; https://0-doi-org.brum.beds.ac.uk/10.3390/agronomy11050836 - 23 Apr 2021

Cited by 20 | Viewed by 7828

Abstract

This work reviews two mechanical separation technologies (screw press and decanting centrifuge) which could be used in the dairy, beef, pig and anaerobic digestion sectors in nutrient-vulnerable zones in order to improve the sustainability of manure and anaerobic digestate management by decreasing agricultural phosphorus loss and reducing environmental impact on water quality. Capital and operating costs, separation efficiency and throughput, and management and processing of separated fractions, including transport costs, environmental impacts and the biosecurity of separated solids for export, were considered. Of the two technologies reviewed, screw press separation is a more cost-effective option (5-fold cheaper per tonne of feedstock) when lower amounts of export of phosphorus off farm are acceptable. For farms and those with anaerobic digesters managing larger volumes of manure/digestate, screw press separation is possible. However if higher levels of phosphorus removal are required, the use of decanting centrifugation is a viable option. Centralised processing facilities could also make use of decanting centrifuge technology to act as processing hubs for local farms within a distance that makes it economical for transport of manure/treated manure to/from the processor (the maximum distance for economical transport of raw manure and separated solids is approximately 70 km and 84 km, respectively). Both separation technologies could be integrated into agricultural manure and digestate management systems in order to provide a more sustainable approach to managing agricultural phosphorus loss and its associated impact on water quality. Screw press and decanting centrifuge separation could reduce phosphorous loss to water bodies by 34% and from 30 to 93%, respectively. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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