Fertilizer Value Research Articles

Struvite production from dairy processing wastewater: Optimizing reaction conditions and effects of foreign ions through multi-response experimental models

Struvite is the preferred form of phosphorus recovery for fertilizer by chemical precipitation. The concentration of phosphorus in raw wastewater from dairy processing is higher than acceptable values for prevention of water pollution. Along with phosphorus, potassium and calcium are its main counterions with high concentration. Thus, calcium phosphate salts are prompt to precipitate and decrease struvite production. The effect of such phosphate counter-ions were optimized using design of experiments and desirability function to maximize both phosphorus recovery and struvite production. Under optimum conditions, the yields were 98.6 ± 1.1 and 85.7 ± 2.5 percent for phosphorus recovery and struvite precipitation, respectively. Factors optimization was achieved with desirability D = 0.995. By in-vitro assay of nutrients release, the product demonstrated better phosphorus availability than the one obtained with high calcium dose in reactor. The obtained molar ratios of dose can serve in wastewater treatment coupled to phosphorus precipitation with a fertilizer value product.

المردود الاقتصادى والبیئی لاستخدام المخلفات الزراعیة فى انتاج البیوجاز

Agricultural waste represents a heavy burden on the environment, in addition to the deterioration of agricultural production. Therefore, the study aimed to provide a sustainable, low-cost, industrially and environmentally safe energy source, in addition to producing organic fertilizers with high fertilizer value and low costs. Therefore, the study relied on conducting an economic feasibility study for biogas units with capacities of 4 m3 and 6 m3 in some modern areas of the two governorates (Fayoum, Assiut) ), Where the total number of the sample items reached 100, and a sensitivity analysis was conducted to measure the tolerance of units and predict the amount of agricultural, plant and animal waste during the period (2019 - 2030), the most important results were that the biogas production unit with a capacity of 4 m3 meets 100% of The household needs from gas and provides 13 job opportunities for seasonal workers, which meet about 35% of the energy needs of the farms, and provide an income estimated at about 4760 pounds annually, as well as the biogas production unit with a capacity of 6 m3 that meets 100% of the household's needs of gas + equivalent 2 cylinders of a cooker per month that can be used in the animal barn or sold and provides 15 job opportunities for seasonal workers, which meet about 50% of the farmer's energy needs, provide an income estimated at about 7040 pounds annually.

PEMAHAMAN ASPEK METAFORA MUSIK LESUNG DALAM GENDHING KUPU TARUNG DI MAGETAN

The uniqueness of the rhytm pattern (gendhing) of the mortar in Magetan lies on the title of the gendhing-gendhing adopted from the name and behavior of the animal. This study focuses on the analysis of metaphorical aspects in the gendhing entitled Kupu Tarung. In this study, metaphor serves as a bridge that communicates certain messages contained in the gendhing Kupu Tarung. One of the results of this analysis is the name of gendhing Kupu Tarung originating from the moment of a mating butterfly, which is then captured in the image scheme, and represented by the creative power (fantasia power) of the community. The collision between the two types of butterfly genitals, which are the essence of the butterfly mating moment, is interpreted in the form of a link between pestles facing each other. Through this mortar gendhing, ancestors transmit the value of fertility (in terms of agriculture and also sexuality) to agrarian communities in the language of art.

Hydrothermal production of algal biochar for environmental and fertilizer applications: a review

Climate change and pollution induced by fossil fuel consumption is calling for alternative, renewable organic products in the context of the future circular economy. For instance, biochar has emerged as a versatile material produced during pyrolysis, hydrothermal liquefaction and gasification of biomass such as algae, plant and organic waste. Here, we review algal biomass, biochar production by hydrothermal liquefaction, biochar properties and biochar fertilizer value for plant growth.

Increasing plant phosphorus availability in thermally treated sewage sludge by post-process oxidation and particle size management

Thermal conversion of phosphorus (P)-rich waste materials such as sewage sludge offers several advantages: generation of bioenergy, concentration of plant nutrients and the destruction of organic pollutants. Different thermal processes modify the feedstock’s chemical and physical structure in differing ways, which also affects P speciation and plant availability in the residual ashes or carbonization products. This study assessed to which extent the P plant availability of ashes and chars produced from one batch of sewage sludge by incineration, pyrolysis or gasification was affected by particle size management and post-process oxidation. Overall, a smaller particle size of the materials as well as post-process oxidation of non-oxidized materials increased the amount of plant-available P in the soil. In a pot experiment, all the materials increased plant biomass compared with the untreated control, but the pyrolysis chars had a substantially greater fertiliser value than the gasification ashes, while the two tested incineration ashes differed in their P fertilizing effect. P availability in non-oxidized materials was partly related to lower process temperatures and lower levels of crystallinity. However, downstream oxidation simultaneously increased crystallinity and P availability in a pyrolysis char and gasification ashes, resulting in an increase in plant P uptake of up to 60%. Results indicate that the oxidation of poorly soluble Fe-phosphates may contribute to the positive effect on P availability. The results suggest that changes to the design and settings of the thermal conversion processes of sewage sludge offer considerable potential for improving P availability in the residual material.

Recycling of municipal solid waste into valuable organic fertilizer towards rejuvenation of crop physiology, yield and soil health

ABSTRACT Though application of chemical fertilizers has contributed significantly to the huge increase in the world food production, the adverse impacts of it are well known. To develop an organic farming system an experiment was conducted on paddy, in old alluvial soil zone, with vermicompost prepared from screened municipality solid waste and different doses of bio-fertilizer and chemical fertilizer which is productive, profitable, enhances soil health and conserves the natural resource. We compared crop yields, crop morphological and morpho-physiological characters along with economical analysis obtained from three consecutive years experiment (2017 to 2019) along with long-term soil sustainability. It has been observed that 25% NPK fertilizer can safely be supplemented by low cost and natural resource-based vermicompost at 2.5 t ha−1 to achieve long-term sustainability in paddy cultivation that is more productive and profitable.

Protecting Thermally Hydrolyzed Biosolids from Pathogenic Bacterial Growth by Addition of Compost

Sludge biosolids for agricultural application represent a valuable fertilizer but also a health risk unless pathogens are effectively reduced, and recontamination controlled. The Post Anaerobic Digestion Thermal Hydrolysis Process (Post-AD THP) is gaining interest due to improved dewaterability, reducing the volume and thus transportation costs of biosolids. However, Post-AD THP results in sterile biosolids easily exposed to recontamination by pathogens due to the lack of microbial competitors. In theory, this could be suppressed by establishing a competing community of harmless bacteria. The theory was tested by monitoring the abundance of Escherichia coli (viable counts) and gene abundance (ddPCR) in wastewater recontaminated Post-AD THP biosolids, with and without addition of compost. Respiration, total bacterial population and bacterial diversity (16S rRNA amplicon sequencing) were used to monitor the microbial community. Biosolids from the regulatory approved methods thermophilic AD (TAD) and Pre-AD THP were tested in parallel for comparison. The results demonstrated that regulatory requirements can be reached by storing the TAD and Pre-AD THP biosolids for 3 days after recontamination and the Post-AD THP biosolids for more than 13 days. However, addition of compost suppressed growth of E. coli in Post-AD THP biosolids, reducing the time to comply with regulative requirements. In conclusion, pathogen growth in Post-AD THP biosolids can be controlled by inoculation with compost.Graphical abstract

Live birth rate from euploid blastocysts is not associated with infertility etiology or oocyte source following frozen-thawed embryo transfer (FET): analysis of 4148 cycles reported to SART CORS.

To investigate whether live birth rates from euploid blastocyst frozen-thawed embryo transfer (FET) cycles are associated with infertility diagnosis or oocyte source. Retrospective analysis of FET cycles reported to SART CORS in 2014. Data from fresh IVF cycles with preimplantation genetic testing for aneuploidy (PGT-A), linked to the first FET cycles, were collected from the 2014 SART CORS database for autologous and donor oocyte cycles. Inclusion criteria were patients undergoing FET with euploid embryos (n = 4148). Demographic data including age, BMI, prior fertility, and etiology of infertility were collected from the retrieval cycle and analyzed. Patients with uterine anomalies, preimplantation genetic testing-mutation (PGT-M) for genetic diseases, gender selection, HLA determination, or systemic and immunologic disorders were excluded. The primary outcome measure was live birth (LB) rate. Potential confounders such as age, prior fertility, and maximum baseline FSH values were analyzed with regression models as indicated. Though age, maximum baseline FSH, and infertility diagnosis were significantly different, LB was similar between patients undergoing autologous or donor oocyte FET cycles. Etiology of infertility was not significantly associated with LB in autologous cycles (p = 0.95). Potential confounders such as maternal age, prior fertility, and maximum baseline FSH were not associated with outcomes; however, maternal BMI was inversely related to LB in autologous cycles, with an odds ratio of 0.97 (95% CI: 0.96-0.98 (rho = - 0.08, p < 0.01)). After controlling for confounding variables, a euploid embryo derived from a donor or autologous oocyte results in similar LB in women with different infertility diagnoses.

Application of Organic Fertilizer Based on Marine Organism in Rice Planting

Yu, X.; Fan, X., and Zhang, B., 2020. Application of organic fertilizer based on marine organism in rice planting. In: Li, L. and Huang, X. (eds.), Sustainable Development in Coastal Regions: A Perspective of Environment, Economy, and Technology. Journal of Coastal Research, Special Issue No. 112, pp. 326-328. Coconut Creek (Florida), ISSN 0749-0208.The traditional way of rice fertilization in China is easy to lead to the loss of soil and water nutrients in rice fields, which leads to the decrease of fertilization efficiency and the pollution of surrounding water bodies. Based on this, this paper first designed the experiment of the influence of the organic fertilizer of the marine organism on the rice, then studied the influence of the organic fertilizer of the marine organism on the rice growth form, finally analyzed the influence of the organic fertilizer of the marine organism on the rice physiological index, thus verified the application value of the organic fertilizer of the marine organism on the rice.

Ammonia volatilization from composting with oxidized biochar

Animal manure, agricultural residues, and other sources of biomass can be diverted from the waste stream and composted into valuable fertilizer. However, composting often results in substantial N loss through NH3 gas volatilization. We investigated biochar's capacity to improve NH3 -N retention during composting of poultry manure and straw. After 7wk, total N loss from composting with unoxidized biochar was twofold and sixfold higher than N loss from composting with oxidized biochar and without biochar (307, 142, and 51mg N g-1 N in the initial compost feedstocks, respectively). When cumulative NH3 -N loss was calculated relative to CO2 -C loss to account for differences in microbial activity, NH3 -N/CO2 -C loss from compost with oxidized biochar was 55% lower than from compost with unoxidized biochar (82% lower based on mass balance). Oxidized biochar particles removed from compost after 7wk retained 16.0mg N g-1 biochar, compared with only 6.1mg N g-1 retained by unoxidized biochar, suggesting that N retention by biochar particles provides a mechanism for reduced NH3 -N loss. These data show that oxidized biochar enhanced microbial activity, doubled composting rate, and reduced NH3 -N loss compared with unoxidized biochar and that biochar's physiochemical characteristics modulate its performance in compost. In particular, the presence of oxidized surface functional groups, which can be increased artificially or through environmental weathering, appear to play an important role in key compost processes. This has implications for other natural and managed systems where pyrogenic organic matter may mediate biological activity and nutrient cycles.

Nitrogen fertilizer value of animal slurries with different proportions of liquid and solid fractions: A 3-year study under field conditions

AbstractThe plant availability of manure nitrogen (N) is influenced by manure composition in the year of application whereas some studies indicate that the legacy effect in following years is independent of the composition. The plant availability of N in pig and cattle slurries with variable contents of particulate matter was determined in a 3-year field study. We separated cattle and a pig slurry into liquid and solid fractions by centrifugation. Slurry mixtures with varying proportions of solid and liquid fraction were applied to a loamy sand soil at similar NH4+-N rates in the first year. Yields and N offtake of spring barley and undersown perennial ryegrass were compared to plots receiving mineral N fertilizer. The first year N fertilizer replacement value (NFRV) of total N in slurry mixtures decreased with increasing proportion of solid fraction. The second and third season NFRV averaged 6.5% and 3.8% of total N, respectively, for cattle slurries, and 18% and 7.5% for pig slurries and was not related to the proportion of solid fraction. The estimated net N mineralization of residual organic N increased nearly linearly with growing degree days (GDD) with a rate of 0.0058%/GDD for cattle and 0.0116%/GDD for pig slurries at 2000–5000 GDD after application. In conclusion NFRV of slurry decreased with increasing proportion of solid fraction in the first year. In the second year, NFRV of pig slurry N was significantly higher than that of cattle slurry N and unaffected by proportion between solid and liquid fraction.

Pyrolysis of Dry Toilet Substrate as a Means of Nutrient Recycling in Agricultural Systems: Potential Risks and Benefits

Biochar is increasingly being applied as a soil amendment in agriculture. Biochar is typically produced from plant biomass and contains relatively low amounts of plant nutrients (e.g., N, P, and K), thus providing limited fertilizer value. Human excreta contains plant nutrients that could be recycled to create sustainable agricultural nutrient cycles. This study investigated the potential of biochar derived from a dry toilet substrate as soil amendment. The substrate consisted of urine, faeces, and wood chips, and was pyrolyzed at 500–650 °C for 10 min. The biochar was analyzed for plant available P, water leachable P and K, carbon stability, pH, electrical conductivity, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), dioxins, and germination tests with barley and lettuce were conducted to estimate the biochar fertilizer value and potential bio-toxicity. The biochar contained 25.0 ± 1.0 g N/kg dry mass (DM), 33.1 ± 2.1 g P/kg DM and 20.7 ± 0.2 g K/kg DM. 65% DM P was extractable by formic acid solution, 31.7% DM P and 60.5% DM K were water leachable in a ten-day column water-leaching experiment. The biochar complied with European regulations for PAHs, PCBs, dioxins and heavy metal concentrations, except for Zn and Ni. Germination of salt-resistant barley was not affected by biochar doses < 50% DM, while salt-sensitive lettuce germination was inhibited at doses ≥ 2% DM, indicating that the dry toilet substrate biochar induced salt stress. Based on these results, it is recommended that urine separation should be considered for biochar of excreta, which could reduce salt stress while maintaining concentrations of “fixed” or bioavailable nitrogen.Graphic

The potential fertilizer value of Namibian beach-cast seaweed (Laminaria pallida and Gracilariopsis funicularis) biochar as a nutrient source in organic agriculture

Biochar has been reported as an efficient tool for carbon sequestration and soil quality improvement, though most research has evaluated the quality of biochar from terrestrial based materials. The study evaluated the macro; micro nutrients and heavy metal concentrations of biochar from seaweeds from Namibian coast. Seaweed species Laminaria pallida and Gracilariopsis funicularis were pyrolysed at different temperatures i.e. control (uncharred); 200; 400; 600 and 800 °C in order to determine the chemical and physical properties of the biochar produced. There were significant interactions (P < 0.05) between temperature and seaweed species on most parameters measured. A pyrolysis temperature of 400 °C resulted in an almost 50% reduction in biochar yield, with higher temperatures resulting in even more yield loss whilst producing biochar with higher alkaline pH above 7 and high EC above 20 mS/cm. G. funicularis biochar resulted in the highest macro element content with total C 38.3%; N 4.3% and P 6.3 g/kg, whilst L. pallida biochar had the highest contents of cations of 16.2 g/kg Ca; 6.4 g/kg Mg; 151 g/kg K and 45 g/kg Na. Higher pyrolysis temperatures did not result in consistent changes in total heavy metal content, with only Cd content being above the maximum permissible limits for biochar of 3.9 mg/kg. Generally, a pyrolysis temperature of 400°C was observed to give biochar with the best quality in terms of macro elements, pH and total C. G. funicularis biochar showed significantly higher nutrient concentrations, therefore has great potential in soil quality improvement.

Suitability of Black Soldier Fly Frass as Soil Amendment and Implication for Organic Waste Hygienization

Because of its nutritious properties, the black soldier fly has emerged as one of the most popular species in advancing circular economy through the re-valorization of anthropogenic organic wastes to insect biomass. Black soldier fly frass accumulates as a major by-product in artificial rearing set-ups and harbors great potential to complement or replace commercial fertilizers. We applied frass from larvae raised on different diets in nitrogen-equivalent amounts as soil amendment, comparing it to NH4NO3 fertilizer as a control. While the soil properties did not reveal any difference between mineral fertilizer and frass, principal component analysis showed significant differences that are mainly attributed to nitrate and dissolved nitrogen contents. We did not find significant differences in the growth of perennial ryegrass between the treatments, indicating that frass serves as a rapidly acting fertilizer comparable to NH4NO3. While the abundance of coliform bacteria increased during frass maturation, after application to the soil, they were outcompeted by gram-negatives. We thus conclude that frass may serve as a valuable fertilizer and does not impair the hygienic properties of soils.

Prospects for the use of peat in biotechnology and for production products of its processing

The article summarizes information on the use of peat - a natural substrate in agro-industrial production, maintaining the cleanliness of the soil and maintaining the cleanliness of the environment. Intensive anthropological activity in modern conditions often leads to the deterioration of the ecological situation of the environment, disruption of the interaction between living organisms and the environment. Biological destruction of the ecological system inherent in a given area can occur under the influence of excessive use of agrochemicals, pesticides, microorganisms with altered characteristics due to interaction with infectious agents or parasites, as well as due to changes in the gene pool of living under the influence of genetic engineering. At the present stage in world development, importance is attached to the approximation of agricultural technologies to the natural conditions of operation. Cleaning the environment, preserving and increasing soil fertility, obtaining high-quality and environmentally friendly agricultural products is a vital but at the same time costly process, which involves significant economic costs. Therefore, there is a need to find cheap ways to solve this problem, replace expensive fertilizers with alternative means, the rational use of biological factors that increase the effectiveness of chemicals. For this purpose, biosubstrates, peat, natural fertilizers and preparations are widely used in world, especially organic agriculture, which are created by the method of selection of effective compositions of microorganism strains in order to activate regenerative processes in soils and ensure their potential. Peat is a natural raw material, an important agro-industrial resource with great potential, which has a multifaceted application. The most reactive part of peat is the population of microorganisms. With the participation of symbiotic microorganisms, the mineralization of peat components occurs, as a result of which nutrients become available to plants. The practice of using peat in agriculture shows its effectiveness as an organic fertilizer, peat-based composts increase soil fertility, agricultural productivity in general, improve environmental cleanliness. Peat has long been used in livestock facilities for bedding. Peat litter has advantages over straw litter due to its high absorption and moisture retention capacity, antibiotic properties. Waste litter is used for composting, as a valuable organic fertilizer to improve soil fertility. Peat is an important source of humic substances in the world, so it is used to produce humic preparations.

Effects of Varying Dietary DL-Methionine Levels on Productive and Reproductive Performance, Egg Quality, and Blood Biochemical Parameters of Quail Breeders.

Simple SummaryThis study investigated the effects of different DL-methionine levels on quail breeders kept from 8–16 weeks of age. The results revealed that using DL-methionine at levels of 0.5 or 1.5 g/kg improved the liver and kidney functions, lipid profile, immunity and antioxidant parameters of quail breeders.The present study was carried out to study the effects of varying dietary DL-methionine (0, 0.5, 1.5, 2.5, and 3.5 g/kg) levels on the productive and reproductive performance, egg quality and blood biochemical parameters of quail breeders. In total, 150 mature Japanese quails at eight weeks of age were randomly allotted to five groups of 30 for each group. Each group included five replicates, each of six quails (four females and two males). The results showed that egg number, egg weight and egg mass were higher (p < 0.05) with the addition of all DL-methionine levels than that of the control group. Quails from the control group had a lower feed intake (p < 0.001) and a worse feed conversion ratio (FCR) than those from the DL-methionine-treated groups. Supplementation of DL-methionine up to 2.5 g/kg in quail diets increased fertility and hatchability percentages. Birds fed DL-methionine at 1.5 g/kg had the best egg production indices, better FCR and the highest values of fertility and hatchability. Egg weight, yolk %, Haugh unit, egg shape index and unit surface shell weight (USSW) were increased and eggshell % was decreased in quail supplemented with DL-methionine levels compared with the control quail (p < 0.05). Dietary DL-methionine levels did not affect (p > 0.05) the hemoglobin (Hb), red blood cells (RBCs), white blood cells (WBCs) and packed cell volume (PCV) of quails. DL-methionine levels (0.5 and 2.5 g/kg) augmented lymphocytes and basophile (p < 0.05). Low DL-methionine levels (0.5 or 1.5 g/kg) improved liver enzymes and kidney functions. Dietary DL-methionine levels (except 3.5 g/kg) declined serum lactate dehydrogenase (LDH) and decreased lipid profile parameters (except high-density lipoprotein—HDL). Supplementation of DL-methionine at 0.5 and 1.5 g/kg increased immunoglobulin (IgG, IgM and IgA) and superoxide dismutase (SOD), total antioxidant capacity (TAC), catalase (CAT) and reduced glutathione (GSH) (p < 0.001) compared with the control. In conclusion, dietary supplementation of DL-methionine (1.5 g/kg) can enhance the reproductive performance and egg quality of quail breeders. DL-methionine use at levels of 0.5 or 1.5 g/kg improved the liver and kidney functions, lipid profile, immunity and antioxidant parameters of Japanese quail.

Direct and correlated responses to selection for autumn lambing in sheep

BackgroundSeasonal reproduction limits productivity, flexibility, and profitability in commercial sheep production. Hormonal and (or) photoperiodic manipulation can be used to control estrous cycles in sheep and reduce limitations that are imposed by the seasonal anestrous but are often impractical or incompatible with the extensive management systems preferred for ruminant livestock. Thus, the current study investigated the use of selection to improve realized fertility (i.e., the proportion of ewes that lambed) following an out-of-season spring joining period (May and June) in a crossbred sheep population.ResultsOver 17 years, estimated breeding values (EBV) for fertility in selected (S) ewes increased by 0.175 (0.01 per year). The mean EBV for fertility of S ewes was greater than that of control ewes by year 10 (P = 0.02), and the fertility of adult (≥ 3 years old) ewes reached 0.88 ± 0.05 by year 17. Lambing began approximately 140 days after the introduction of rams, and 64% of the S ewes that lambed did so in the first 17 days of the potential lambing season, which indicated that most of the S ewes were cycling at the time of ram introduction and were not induced to cycle by the introduction of breeding males (i.e., the so-called “ram effect”). Animals in the S line had modest increases in body weight and scrotal circumference. A modest negative trend in the additive maternal effect on birth weight was observed but was reversed by additional selection on EBV for maternal birth weight. The heritability of litter size in autumn lambing was low (0.04) and could potentially limit the response to selection for this trait.ConclusionsSelection improved realized ewe fertility in out-of-season mating, with absolute increases of approximately 1% per year in the percentage of joined ewes that lambed in the autumn. Genetic antagonisms with other performance traits were generally small. A modest antagonism with maternal breeding values for birth weight was observed but it could be accommodated by selection on EBV for maternal birth weight. Our results support results of previous studies that indicate that these selected ewes had one of the shortest seasonal anestrous periods reported for temperate sheep breeds and that spring-lambing lactating ewes from the selection line were capable of relatively rapid rebreeding in the spring.

Does Ecological Harshness Influence Men’s Perceptions of Women’s Breast Size, Ptosis, and Intermammary Distance?

Breasts are sexually dimorphic physical characteristics, and they are enlarged post-puberty suggesting that they have been driven by sexual selection to signal fertility and residual reproductive value. Although different hypotheses have attempted to explain why men are attracted to women’s breasts, the role that ecology plays in men’s perceptions of women’s breasts has been limited. The current study used an ecologically harsh prime to investigate if ecological harshness influenced men’s perceptions of women’s breast size, ptosis (i.e., sagginess), and intermammary distance. Men were primed with an ecological harsh prime (i.e., economy uncertainty) and asked to rate women whose breast size, ptosis, and intermammary distance (i.e., cleavage) had been manipulated. Ecological harshness only influenced men’s perceptions of women’s breasts for reproductive success. Overall, men rated women with larger breasts as more attractive, fertile, healthier, reproductively successful, and likely to befriend. The study contributes to the overall literature on men’s perceptions of women’s breasts and suggests that ecological harshness may influence men's perceptions of women's reproductive success.

Farmers’ knowledge, perception, and use of phosphorus fertilization for cowpea production in Northern Guinea Savannah of Nigeria

Cowpea (Vigna unguiculata L. Walp) is an important legume crop, especially in sub-Saharan Africa. Poor soil fertility is among the major abiotic factors that contribute to this crop's low yield. Phosphorus (P)-based fertilizers significantly increase cowpea yields but these fertilizers are not well adopted by smallholder cowpea farmers. To understand why, we surveyed 420 farmers across three major cowpea-producing states in Nigeria: first, we assessed the cowpea farmers' knowledge and perception of the need for fertilizers, especially P fertilizers; and, second, we identified factors that determine the use – or non-use – of P-based fertilizers. Although over 80% of farmers surveyed were aware of the value of fertilizers as a yield-increasing factor and were able to identify crops suffering from nutrient deficiency, only 10% used P-based fertilizers like single super phosphate (SSP) and another 11% used combinations of nitrogen, phosphorus, and potassium compound fertilizers and SSP for cowpeas. Reasons for not using P-containing fertilizers included high cost, poor availability in rural markets, and lack of awareness on the need to use P fertilizers. Additionally, many growers believed that cowpeas do not require fertilizers, especially if the previous crop had been maize. Our findings are important for strategies to increase the productivity of cowpeas among smallholder growers especially in the northern regions of Nigeria and beyond, where subsistence farming systems are prevalent. Increased cowpea production through the adequate use of inputs like P fertilizers will support Nigeria's effort to reduce its large imports of cowpea grain from neighboring countries. Our survey further demonstrated that P-containing fertilizers are crucial production inputs for increased cowpea production in these regions and in areas with similar traditional farming practices. Our results will benefit breeders, development partners, extension personnel, and other stakeholders in cowpea value chains.

Biochar and its importance on nutrient dynamics in soil and plant

Biochar, an environmentally friendly soil conditioner, is produced using several thermochemical processes. It has unique characteristics like high surface area, porosity, and surface charges. This paper reviews the fertilizer value of biochar, and its effects on soil properties, and nutrient use efficiency of crops. Biochar serves as an important source of plant nutrients, especially nitrogen in biochar produced from manures and wastes at low temperature (≤ 400 °C). The phosphorus, potassium, and other nutrient contents are higher in manure/waste biochars than those in crop residues and woody biochars. The nutrient contents and pH of biochar are positively correlated with pyrolysis temperature, except for nitrogen content. Biochar improves the nutrient retention capacity of soil, which depends on porosity and surface charge of biochar. Biochar increases nitrogen retention in soil by reducing leaching and gaseous loss, and also increases phosphorus availability by decreasing the leaching process in soil. However, for potassium and other nutrients, biochar shows inconsistent (positive and negative) impacts on soil. After addition of biochar, porosity, aggregate stability, and amount of water held in soil increase and bulk density decreases. Mostly, biochar increases soil pH and, thus, influences nutrient availability for plants. Biochar also alters soil biological properties by increasing microbial populations, enzyme activity, soil respiration, and microbial biomass. Finally, nutrient use efficiency and nutrient uptake improve with the application of biochar to soil. Thus, biochar can be a potential nutrient reservoir for plants and a good amendment to improve soil properties.