Fertilizer Supply Research Articles

Long-term alfalfa planting mediates the coupling of soil water and organic carbon storage in a semi-arid area of the Loess Plateau, China

The key to restoring arid and semi-arid ecosystems is maintaining soil water and organic carbon contents. Alfalfa (Medicago sativa L.) is a high-yield perennial forage crop and performs ecological functions as a drought-resistance leguminous herb. It has been widely planted for reconstruction of degraded soils in the Loess Plateau in northwestern China, but long-term planting may affect soil carbon–water coupling and lead to crop yield reduction. To maximize the benefits of reconstructed grassland, this study explored the couplings of soil water, organic carbon, and alfalfa productivity along a reconstruction chronosequence in a semi-arid area of the Loess Plateau. Space-for-time substitution approach was used to select different-aged stands of reconstructed grassland (1, 5, 7, 10, 15, 20, 30 years old). Alfalfa above-ground biomass (AGB), soil water storage (SWS), organic carbon storage (SOCS), and carbon–water coupling coordination degree (D) were measured in the 0–100 cm soil profile. Alfalfa AGB reached a peak in the 7th year, and the degradation began in the 10th year. Both SWS and SOCS varied nonlinearly with stand age. The greatest loss of SWS occurred in the 15th year (80–100 cm depth), whereas the largest increase of SOCS occurred in the 30th year (0–20 cm depth). There was a negative feedback relationship between AGB and SWS over the 30-year study period (Pearson r = −0.835, P = 0.098). AGB and SOCS initially showed a trade-off within the first 10 years (Pearson r = −0.7431, P = 0.2569), in contrast to their positive feedback in the 20–30th years (Pearson r = 0.9978, P = 0.0421). A decoupling between SWS and SOCS (D < 0.6) was observed after 12 years of alfalfa planting. For agricultural production, a greater supply of water and organic fertilizer is required from the 7th year of alfalfa planting, and reseeding may be needed around the 10th year to prolong the life of alfalfa community. Alfalfa should be planted for no more than 12 consecutive years in the study area for ecological protection.

Optimizing nitrogen fertilizer for improved root growth, nitrogen utilization, and yield of cotton under mulched drip irrigation in southern Xinjiang, China

The root system plays a crucial role in water and nutrient absorption, making it a significant factor affected by nitrogen (N) availability in the soil. However, the intricate dynamics and distribution patterns of cotton (Gossypium hirsutum L.) root density and N nutrient under varying N supplies in Southern Xinjiang, China, have not been thoroughly understood. A two-year experiment (2021 and 2022) was conducted to determine the effects of five N rates (0, 150, 225, 300, and 450 kg N ha−1) on the root system, shoot growth, N uptake and distribution, and cotton yield. Compared to the N0 treatment (0 kg N ha−1), the application of N fertilizer at a rate of 300 kg N ha−1 resulted in consistent and higher seed cotton yields of 5875 kg ha−1 and 6815 kg ha−1 in 2021 and 2022, respectively. This N fertilization also led to a significant improvement in dry matter weight and N uptake by 32.4% and 53.7%, respectively. Furthermore, applying N fertilizer at a rate of 225 kg N ha−1 significantly increased root length density (RLD), root surface density (RSD), and root volume density (RVD) by 49.6–113.3%, 29.1–95.1%, and 42.2–64.4%, respectively, compared to the treatment without N fertilization (0 kg N ha−1). Notably, the roots in the 0–20 cm soil layers exhibited a stronger response to N fertilization compared to the roots distributed in the 20–40 cm soil layers. The root morphology parameters (RLD, RSD, and RVD) at specific soil depths (0–10 cm in the seedling stage, 10–25 cm in the bud stage, and 20–40 cm in the peak boll stage) were significantly associated with N uptake and seed cotton yield. Optimizing nitrogen fertilizer supply within the range of 225–300 kg N ha−1 can enhance root foraging, thereby promoting the interaction between roots and shoots and ultimately improving cotton production in arid areas.

Evaluation of Nitrogen Fertilizer Supply and Soil Nitrate Thresholds for High Yields of Foxtail Millet

Foxtail millet is an important cereal crop in the North China Plain. However, excessive nitrogen fertilizer application over the years has led to declining yield and soil quality. This study investigated nutrient management strategies for foxtail millet based on crop yield levels and soil nutrient availability. In a field where targeted fertilization was conducted over six seasons, nitrogen fertilization effects and the dynamics of soil-available nitrogen were monitored continuously for two consecutive years (2022–2023) across five different foxtail millet varieties with varying yield levels. The study aimed to determine the optimal nitrogen application rate for achieving a high yield of foxtail millet, the minimum soil nitrate threshold required to maintain soil fertility, and the effective nitrogen application rate range for sustaining soil-available nitrate levels. Results showed that fertilization significantly affected dry matter weight during flowering, while variety affected dry matter weight at maturity. The average nitrogen application rate for achieving high yield across all five millet varieties was 141.3 kg·ha−1. Specifically, the average nitrogen application rate of nitrogen-efficient varieties achieving high yield (5607.32–5637.19 kg·ha−1) was 151.5 kg·ha−1, while the average nitrogen application rate of nitrogen-inefficient varieties achieving high yield (4749.77–4847.74 kg·ha−1) was 134.5 kg·ha−1. Soil NH4+-N and NO3−-N content increased when nitrogen application rate exceeded 360 kg·ha−1, posing environmental risks. To achieve high yield, soil nitrate levels would be maintained at an average of 17.23 mg·kg−1 (before sowing) and 9.75 mg·kg−1 (at maturity). A relationship between soil nitrate and nitrogen application rate was established: y = 867.5 − 50z (where y represents the optimal nitrogen application rate for high yield (kg·ha−1), and z represents soil NO3−-N content in the 0–20 cm layer before sowing, ranging from 10.0 to 17.35 mg·kg−1), which provided a practical method for nitrogen fertilization to achieve high yield of foxtail millet. In this study, the fertilization strategy was optimized according to soil nutrient level and yield targets, and the nitrogen application rate was controlled within 360 kg·ha−1 based on the soil nitrate nitrogen content, which will be instructive for reducing fertilizer use, maximizing fertilizer efficiency, and increasing yield.

Conflict between Fulani herders and village landowners in Ghana: capitalism, climate change, and peasant struggles

In discussions of the capitalism–climate change interplay in the agrarian world, the intrusiveness of corporate and state-guided capitalism has been pre-eminent. This ‘hard capital’ focus obscures indirect linkages like how ‘soft capital’, although disoriented from raping nature, unlike the former, exacerbates climate change effects in ways that accelerate the destabilisation of agrarian economies. This indirect connection is evident in agrarian settings in Ghana’s Northern Region, where the resultant peasants’ revolt is directed at neither corporations nor the state but rather local landowning elites (soft capital), who transfer the burden of the twin pressures of climate change and hard capital (state intervention and privatisation of fertiliser supply) to their labourers. Using Marxian social relations of production as a theoretical lens, this paper unpacks how this capitalism–climate change interface plays out in Gushiegu, Northern Ghana. By highlighting that interface and the resultant agrarian struggles, this paper does two things: (1) invites agrarian scholars to transcend the commercialisation of agriculture and carbon capitalism in analysing how the intersection of capitalism and climate change destabilises the agrarian world; (2) encourages scholarship that transcends the more obvious herder–farmer conflicts over land and water in examining the destabilising effects of the aforementioned intersection.

P-graph and Monte Carlo simulation approach for sustainable and risk-managed CDR portfolios

Negative emission technologies (NETs) that perform carbon dioxide removal (CDR) are now part of the decarbonization strategies to reach net-zero emissions. However, NETs will consume resources that will compete with other societal priorities. Thus, NET portfolios that provide a technology mix are better for sustainability and risk management. This study proposes a two-step approach to optimize and check the robustness of NET portfolios, particularly for industrial-scale applications where resource availability fluctuates due to variations in energy, water, and fertilizer supply. The first step involves the process graph (P-graph) framework to generate optimal and near-optimal solution structures at minimum cost. The second step measures the probability of failure of these solutions against resource availability variations through Monte Carlo simulation. By comparing the cost and probability of failure, decision-makers can select a recommended solution that strikes a balance between robustness and cost. The proposed approach is demonstrated in two case studies involving NET portfolios. The first case study investigates the performance of optimal and near-optimal solutions of NET portfolios, while the second case study focuses on bioenergy with carbon capture and storage portfolios using different feedstocks. In both cases, the results show that near-optimal solutions with higher costs but lower probabilities of failure exist, enabling decision-makers to weigh robustness against cost. This study contributes to developing and analyzing robust decarbonization decision support models, addressing the critical need for sustainable and risk-managed NET portfolios.

Long-term potato response to different irrigation scheduling methods using saline water in an arid environment

Crops’ water requirement is generally higher than the annual average precipitation in arid environments characterized by scarce freshwater resources. While using saline water for irrigation can help sustain agriculture in water-stressed regions, several challenges arises concerning productivity and soil salinization. However, adoption of efficient irrigation techniques such as drip irrigation, irrigation scheduling, and deficit irrigation can help optimize water productivity and mitigate salinity problems in irrigated agriculture. In southern Tunisia, potato is considered among the main cultivated horticultural crops due to its high economic value while it is considered as a crop sensitive to salinity. This crop (cv. Spunta) was the subject of long-term studies (2002–2020) conducted during the fall period in the arid region of Médenine. The crop response to full and deficit irrigation with saline water was assessed for several seasons under contrasting climatic conditions. Scheduling using the soil water balance (SWB) method consisted of the total and/or partial replacement of accumulated crop evapotranspiration (ETc), as derived from climatic data and crop coefficients. The impact of decreasing amounts of irrigation waters on crop yield and soil salinity with waters having a salinity ranging between 3 and 7 dS m−1 was evaluated. Results showed improvements in yield (30% to 37%) obtained with the SWB strategy under actual farming conditions, supporting the use of this strategy for irrigation. Appropriate scheduling also seems to be a key element in saving water (15%–22%) and in reducing risks of soil salinization. In the dry environment of southern Tunisia, optimum supply seems to correspond to a replacement of 100% to approximately 70%–80% of ETc. Applying such irrigation levels resulted in a lower salinity buildup in the root zone and higher crop water productivity. Natural salt leaching seems to be more effective under a more humid soil profile. Yield decreases and soil salinity increases almost linearly (r2 = 0.60) with decreasing irrigation water amounts. Future work should focus on the integration of management practices when using saline water. Investigating the relationship and interaction between irrigation amounts, cultivar, fertilizer supply, and salt leaching will help in resolving productivity and environmental issues.

Sustainable Supplier Selection Using Fuzzy AHP (AHP-F) and Fuzzy ARAS (ARAS-F) Techniques for Fertilizer Supply in the Agricultural Supply Chain

Implementing the right strategies in the agricultural supply chain in the supply of seeds, pesticides, fertilizer, energy, fuel and agricultural mechanization tools and equipment has a great role in increasing agricultural productivity. The main purpose of the study is to rank and evaluate alternatives in choosing a sustainable fertilizer supplier in the agricultural supply chain by using AHP-F and ARAS-F techniques. In an environment of uncertainty and complex supply chain structure, multi-criteria decision making (MCDM) methods are widely used to solve supplier selection problems. In this study, the importance levels and weights of the criteria in the selection of sustainable fertilizer suppliers were measured by the AHP-F method. The criteria that are important for fertilizer supplier selection were evaluated by taking expert opinions, the uncertain and uncertain opinions of the decision makers were modeled with the AHP-F approach and the weights of the criteria were determined. Among the criteria, resource consumption (FSC05) has the highest weight. Then, alternative rankings were obtained with the ARAS-F method. Fertilizer supplier alternatives in the agricultural supply chain were ranked with the ARAS-F method, using the criterion weights found with AHP-F. In the ranking of alternatives, alternative fertilizer supplier FS03 ranked first with the highest value. This study provides a resource for businesses and other stakeholders to make decisions regarding sustainable fertilizer supplier selection.

Optimisation of Fertiliser Delivery Distribution from Distributor to Farmer Group Using Excel Solver in Tanjung Village

Subsidised fertilisers are declared as goods that are monitored for distribution with a specific target, namely farmers. In the distribution process, the government cooperates with various components including the Ministry of Industry and Trade, the Ministry of Agriculture, the Ministry of State-Owned Enterprises and the Ministry of Home Affairs. At the same time, transportation and communication technologies continue to develop rapidly, such as mobile communications and the Internet, which drive the continuous development of the supply chain and technologies related to its regulatory management. This research aims to find out how to optimise the fertiliser transprortation Fertiliser Delivery Distribution and a series of fertiliser supply systems from Distributors to Farmer Groups Using Excel Solvers in Tanjung Village so as to provide better user control. The benefits of this research for distributors can help buffer distributor management to determine the quantity and time of delivery of subsidised fertiliser to official kiosks. The research method uses a case study which is a method of collecting and processing data through review / study of various research reports, flowsheets, research journals, as well as books and other relevant literature.

The supply of phosphate fertilizers affects the uptake of macronutrients and the productivity of Brachiaria cultivars during the establishment period

Phosphate fertilizer is necessary in Brachiaria species to boost fodder yield and nitrogen uptake. Know Plant response the phosphate guides nutrient dosing for optimal growth. The goal was to assess how phosphorus (P) dose affected forage production and macronutrient uptake in forage plants during the establishment period. The experimental design was in a 9 × 2 factorial scheme. Nine forage plants of the genus Brachiaria were evaluated: B. decumbens cv. Basilisk, B. humidícola cv. BRS Tupi, B. humidícola, B. ruziziensis, B. brizantha cvs. Marandu, BRS Piatã, Xaraés, BRS Paiaguás and hybrid (B. brizantha × B. ruziziensis) cv. BRS Ipyporã, two doses of P: 6 and 72 mg/dm−3 of P. At the lowest dose of P, the most productive forages were Paiaguás and ruziziensis. In contrast, at the highest dose of P, the forages ruziziensis, Basilisk, Piatã, Paiaguás and Xaraés were the most productive. When compared to the use of 6 mg/dm−3 P, dose of 72 mg/dm−3 P generated an increase in forage production of 803%. The greater forage production provided by the higher P content in the soil is reflected in greater uptakes of macronutrients by forages, following the decreasing order of N > K > Mg > Ca > S = P. The highest efficiencies to produce 1 g of dry matter (DM) at doses of 6 and 72 mg/dm−3 of P were observed in the Paiaguás and humidicola, respectively. In soils with more readily available phosphorus, macronutrient conversion into plant material is more effective. As a result, grasses of the genus Brachiaria generate more DM with less mineral content.

Optimal Nitrogen Fertilizer Rates for Soybean Cultivation

The soybean (Glycine max. L. Merr) can satisfy a large portion of its requirement for nitrogen (N) by living in symbiosis with symbiotic bacteria. However, this source of N may be inadequate in varieties with high yield potential. To fully exploit this potential, soybeans should additionally utilize mineral forms of nitrogen present in the soil. The aim of this study was to determine the effect of varied nitrogen fertilizer application rates on the dry weight of the separated parts of soybean plants and the whole plant, including the number and weight of root nodules, the potential to reduce atmospheric nitrogen (N2), and the content and uptake of nitrogen. Four levels of pre-sowing nitrogen fertilizer supply were tested: 0, 60, 120, and 180 kg N·ha−1. Measurements of the tested parameters were taken during the flowering stage and the fully ripe stage. During the flowering stage, a reduction in the number of root nodules was observed following the application of 120 and 180 kg N·ha−1. In the fully ripe stage, each increase in nitrogen application caused a systematic decrease in the number of nodules on the roots. Increasing the level of nitrogen application therefore reduced the N2 fixation potential of soybeans, regardless of the developmental stage. The use of high doses of nitrogen in soybean cultivation did not increase seed yield or the weight of the entire plant. With high doses of nitrogen, the content and accumulation of nitrogen in soybean seeds and total mass did not increase. Therefore, the content and yield of crude protein did not increase. The main organ of nitrogen accumulation in the soybean flowering stage was the leaves (58.6–64.8% of total N uptake), however, in the fully ripe stage, it was the seeds (66.8–74.2% of total N uptake).

Cultivation Technologies and Inorganic Fertilizer Norms when Growing Potatoes in Azerbaijan

Technologies for applying granular fertilizers when growing potatoes in the farms of the Gazakh-Tuz economic region of Azerbaijan are presented. An analysis of existing technical means used to effectively prepare soil for growing potatoes was carried out. By means of a stepwise supply of inorganic fertilizers to the soil using the method of differentiated distribution, theoretical studies were carried out and analytical expressions were obtained to substantiate the parameters of the working bodies of the corresponding unit. An analysis of existing technologies and technical means for growing potatoes shows that the application of fertilizers, which provide the required amount of nutrition for the cultivated crop, prevents sufficient nutrition of the soil when carried out in a surface manner and subsequent incorporation into the soil. To avoid this, inorganic fertilizers are applied to the soil by working groups and converted into the soil by cutting off lower layers to protect the mound and optimal soil structure. By systematically filling the soil through differentiated distribution of inorganic fertilizers, analytical studies were carried out and analytical expressions were obtained to check the parameters of the unit’s labor force.

Optimization model of water-fertilizer coupling in garden plant cultivation based on big data analysis

This study is dedicated to the development of an Internet of Things (IoT)-based water-fertilizer coupling optimization model for landscape plant cultivation using big data analysis technology to solve the problems of resource wastage and unstable plant growth quality in traditional water-fertilizer management. Through real-time monitoring of soil, climate and plant physiological indicators, combined with autoregressive moving average model and other prediction means, to achieve accurate prediction of plant water and fertilizer demand and dynamic coupling management. The model is able to customize personalized water and fertilizer supply strategies according to plant species, growth stages and environmental conditions, thus enhancing the efficiency of water and fertilizer utilization, promoting healthy plant growth, and enhancing the effect of urban greening.

Ammonia Emissions, Soil Chemical Properties and Fruit Quality According to the Soil Supply of Urea and Organic Fertilizer in a ‘Campbell Early’ Vineyard

Ammonia Emissions, Soil Chemical Properties and Fruit Quality According to the Soil Supply of Urea and Organic Fertilizer in a ‘Campbell Early’ Vineyard

IoT Based Smart Agriculture Using Machine Learning

Agriculture is one of the crucial sources of economic growth in the country. Agriculture plays a major role in increasing the overall economy of any country. Many countries are having tremendous growth in the production of crops as the demand for food grains and supply increases. India is one of the leading countries in producing a variety of different crops. However, most parts of India are still using the traditional methods for implementation and cultivation of crops, due to which farmers are facing a loss in their production due to inadequate supply of fertilizers and uncertain climatic conditions. To overcome this, there is a need to develop a system that will look for these soil, temperature, and climatic conditions. IoT-based Smart Agriculture using Machine Learning talks about the use of IoT and Machine Learning techniques that will not only look for sensor data but also recommend the farmers the suitable fertilizers and crops to be grown. Smart sensors will be used to get the values related to soil moisture, temperature, humidity, and pH values. These sensors will check for suitable soil conditions, and how wet or dry the soil is, and will also look for temperature values. The real-time data will be fetched and displayed on the live monitoring webpage and Android applications. We can get timely information about the soil moisture value and suitable temperature and humidity value. With the help of Data Analysis techniques, we can figure out which data to take for further exploration. Historical datasets that are publicly available can be used for training and building Machine Learning models. Farmers can access information about their field data, and machine learning algorithms will help the farmers in making informed decisions about what crops to grow in the specific environment. Keywords— Internet of Things, Sensors, Soil moisture, Temperature, Humidity, Microcontroller, Smart Agriculture, Recommendation Model, Crop Prediction, Fertilizers Prediction, Machine Learning Model.

A Study on the Impacts of Fertilizer Crisis on Paddy Cultivation in Five Selected Divisional Secretariat Divisions of Trincomalee District During Maha 2021/22

Rice is one of the most important cereal crops in the world. With population growth, farmers have to increase paddy production to meet existing as well as future demand. Fertilizer is the major input in rice production. Growth and yield traits of rice are affected by improper and imbalanced application of plant nutrients. Hence, suitable practices of adequate rate and timing of fertilizer application are needed to increase the rice yield. In May 2021, Imports & Exports (Control) Regulation No 07 of 2021 was issued, banning the importation of chemical fertilizers, pesticides, & herbicides in Sri Lanka. Low fertility of paddy soil created the need for adequate and constant supply of chemical fertilizers in paddy cultivation, which is a major threat to production and endangers the national food security and economy of Sri Lanka, especially in the major cropping season of Maha 2021/22. Therefore, a questionnaire survey was conducted to investigate the impact of the fertilizer crisis in major paddy-cultivating Divisional Secretariat divisions of the Trincomalee district. The random sampling method was used to select respondents for the survey, and the collected data were statistically analyzed by SPSS version 26.0 software. The results revealed that the majority of the farmers experienced a 50% yield reduction compared to the last cropping season of Maha 2020/21 in the entire five DS divisions. The seedling stage was highly affected during the fertilizer crisis in paddy cultivation in all five DS divisions. Further, the cost of production in paddy cultivation increased by more than 50% during the fertilizer crisis compared to the cost involved in Maha 2020/21. The potential for organic manure production is very poor, while the majority of farmers are interested in adopting the sustainable farming system of the Integrated Plant Nutrient System through the judicious application of chemical and organic fertilizers received on a subsidy basis, according to the present government’s fertilizer policy, which emphasizes 70% of inorganic fertilizers and 30% of organic manure application to improve sustainability in paddy cultivation in the country.

Impact of Crop Production on Economic Growth in Nigeria, 1981 – 2018

This study examined the impact of crop production on economic growth in Nigeria utilizing annual time series data from 1981 to 2018. The study used Johansen cointegration test, Vector Error Correction test, the impulse response functions and variance decomposition for data analysis after the data series were checked against unit root problem using the Augmented Dickey Fuller unit root test. The study tested and found that increase in the production of cassava, cocoyam, groundnut, guinea corn, maize, millet, rice and yam spurs economic growth in Nigeria in the long-run except for cotton production and with only groundnut production contributing significantly to the output of the Nigerian economy in the short- run. The study, therefore recommends that the Nigerian government should encourage farmers in the production of crops through supply of fertilizer to increase their productivity and food output while improving their use of modern seedlings and technology in the production that may in turn increase the crop production while farmers should be encouraged to adapt best practices in farming to maximize crop yield.

Transcription factor OsSHR2 regulates rice architecture and yield per plant in response to nitrogen.

Mutation of OsSHR2 adversely impacted root and shoot growth and impaired plant response to N conditions, further reducing the yield per plant. Nitrogen (N) is a crucial factor that regulates the plant architecture. There is still a lack of research on it. In our study, it was observed that the knockout of the SHORTROOT 2 (OsSHR2) which was induced by N deficiency, can significantly affect the regulation of plant architecture response to N in rice. Under N deficiency, the mutation of OsSHR2 significantly reduced root growth, and impaired the sensitivity of the root meristem length to N deficiency. The mutants were found to have approximately a 15% reduction in plant height compared to wild type. But mutants showed a significant increase in tillering at post-heading stage, approximately 26% more than the wild type, particularly in high N conditions. In addition, due to reduced seed setting rate and 1000-grain weight, mutant yield was significantly decreased by approximately 33% under low N fertilizer supply. The mutation also changed the distribution of N between the vegetative and reproductive organs. Our findings suggest that the transcription factor OsSHR2 plays a regulatory role in the response of plant architecture and yield per plant to N in rice.

Fertilizer Addition Modifies Utilization of Different P Sources in Upland Rice on Strongly P-fixing Andosols

AimsHigh Phosphorus (P) efficiencies such as internal P utilization efficiency (PUE) and P acquisition efficiency (PAE) are crucial for upland rice production, particularly on highly P-fixing soils like Andosols. While the effect of root traits associated with high PAE in upland rice has been studied intensively, less attention has been given to the origin of P (native soil-P versus fertilizer-P) taken up by plants when evaluating differences in P efficiency. Here we aim to evaluate the efficiency of different upland rice genotypes to acquire native soil-P and fertilizer-P.MethodsFour upland rice genotypes with varying PAE were grown in an Andosol at low- and high-P fertilization level and harvested 9 and 34 days after emergence. Fertilizer-P was labeled with 33P to distinguish between the efficiency to acquire P originating from native soil and fertilizer by measuring plant P uptake.ResultsIncreased fertilizer supply enhanced native soil-P uptake. Under low-P conditions the genotype DJ123 showed a superior PAE and an increased acquisition of native soil-P while AB199 was identified to have a superior internal PUE under P deficient conditions. Differences between genotypes in overall PAE under high-P conditions were not significant but the distinction of P sources showed that genotype DJ123 acquired significantly more native soil-P per unit root than all other genotypes.ConclusionsOur results indicate that variations in PAE among genotypes are associated with their ability to access native soil-P. DJ123 emerged as the most adept genotype in acquiring sparingly soluble native soil-P and future studies should unravel the rhizosphere processes underlying increased PAE of native soil-P.

Consequential LCA of NPK fertilizers from microbial, animal, plant, and mineral origin highlights resource constraints and environmental impacts

The production and use of mineral fertilizers lead to severe environmental impacts, therefore initiatives such as the European Green Deal promote organic farming and nutrient circularity. However, many organic fertilizers (those containing organic carbon and nutrients of exclusively biological origin) face constraints due to resource availability, and it is paramount to understand their environmental impacts to prevent unforeseen effects. This study employed a consequential life cycle assessment (LCA) to compare the environmental impact of mineral fertilizer to three types of organic fertilizers: animal-, plant-, and innovative microbe-based, considering market constraints and marginal suppliers. Organic fertilizers were complemented with mineral products to yield NPK compound fertilizers containing 1 t of nitrogen, 0.44 t of phosphorus, and 0.83 t of potassium (multi-substance functional unit). The findings reveal that 9 out of the 17 studied organic fertilizers are constained products, and that their demand is met through the supply of mineral fertilizers, soybean meal, and maize or barley grain. Consequently, for the transition to a circular and organic agrifood system, the focus should shift toward untapped resources like microbial fertilizers sourced from food and beverage industry wastewater, and sewage sludge. Constrained markets vary with time and geographical location, emphasizing the importance of context-specific decision-making. The impact of mineral fertilizers is relatively low across impact categories, but the gap between them and energy-intensive organic fertilizers narrows in an industrial symbiosis scenario where waste heat is available. An additional assessment of soil organic carbon estimated the contribution of organic fertilizers to the “4 per 1000" initiative's goal for soil carbon storage. Organic fertilizer application alone only achieves this goal in one scenario (rapeseed meal), but combining it with other management practices like crop rotation offers a promising strategy. The scenario that included fertilizer transport showed the potential for reduced environmental impacts by applying locally available by-products as organic fertilizer instead of imported mineral fertilizers. Overall, the results call for caution when transitioning from mineral to organic fertilizers as their availability and environmental impact are not self-evident.

Feasibility study of Aesculus turbinata fruit shell-derived biochar for ammonia removal in wastewater and its subsequent use as nitrogen fertilizer

In the face of increasing nitrogen demand for crop cultivation driven by population growth, this study presents a sustainable solution to address both the heightened demand and the energy-intensive process of nitrogen removal from wastewater. Our approach involves the removal of nitrogen from wastewater and its subsequent return to the soil as a fertilizer. Using biochar derived from Aesculus turbinata fruit shells (ATFS), a by-product of post-medical use, we investigated the effect of pyrolysis temperature on the NH4–N adsorption capacity of ATFS biochar (ATFS-BC). Notably, the ATFS-BC pyrolyzed at 300 °C (ATFS-BC300) exhibited the highest NH4–N adsorption capacity of 15.61 mg/g. The superior performance of ATFS-BC300 was attributed to its higher number of oxygen functional groups and more negatively charged surface, which contributed to the enhanced NH4–N adsorption. The removal of NH4–N by ATFS-BC300 involved both physical diffusion and chemisorption, with NH4–N forming a robust multilayer adsorption on the biochar. Alkaline conditions favored NH4–N adsorption by ATFS-BC300; however, the presence of trivalent and divalent ions hindered this process. Rice plants were cultivated to assess the potential of NH4–N adsorbed ATFS-BC300 (NH4-ATFS-BC300) as a nitrogen fertilizer. Remarkably, medium doses of NH4-ATFS-BC300 (594.5 kg/ha) exhibited key agronomic traits similar to those of the commercial nitrogen fertilizer in rice seedlings. Furthermore, high doses of NH4-ATFS-BC300 demonstrated superior agronomic traits compared to the commercial fertilizer. This study establishes the viability of utilizing ATFS-BC300 as a dual-purpose solution for wastewater treatment and nitrogen fertilizer supply, presenting a promising avenue for addressing environmental challenges.