Form Of Fertilizer Research Articles

Uptake of phosphorus from surfactant solutions by wheat leaves: spreading kinetics, wetted area, and drying time.

The delivery and uptake of nutrients at the surface of plant leaves is an important physicochemical phenomenon that depends on leaf surface morphology and chemistry, fertilizer formulation chemistry (including adjuvant and associated surfactants), wetting dynamics, and many other physical, chemical and biological factors. In this study, the role of spreading dynamics in determining uptake of the macronutrient phosphorus from phosphoric acid fertilizer solution in combination with three different adjuvants was measured in the absence of droplet run-off and splashing. When run-off and splashing losses were zero, spreading and drying rates had a small to negligible effect on the uptake efficiency. The results suggest that uptake may be much less sensitive to the specific choice of adjuvant and long time-scale spreading behaviour than one might intuitively expect.

FERTILIZANTE DE LIBERAÇÃO LENTA NO DESENVOLVIMENTO DE MUDAS DE <i> Anadenanthera peregrina </i> (L.) Speg. (ANGICO-VERMELHO) E <i> Schinus terebinthifolius </i> Raddi (AROEIRA-VERMELHA)

http://dx.doi.org/10.5902/1980509820582Com o objetivo de avaliar o desenvolvimento de duas espécies arbóreas nativas - Anadenanthera peregrina (angico-vermelho) e Schinus terebinthifolius (aroeira-vermelha) - submetidas a doses de fertilizante de liberação lenta na formulação 13-06-16, conduziu-se um experimento em viveiro utilizando uma mistura de matérias-primas com composto orgânico, vermiculita e Plantmax® para compor substrato base. O experimento foi conduzido no delineamento experimental inteiramente casualizado com seis tratamentos em quatro repetições. Os tratamentos foram: T1–0 kg (testemunha); T2–2 kg; T3–4 kg; T4–6 kg; T5–8 kg e T6–10 kg de fertilizante de liberação lenta por metro cúbico de substrato base. Avaliou-se aos 189 dias após a semeadura a altura total, diâmetro do colo, biomassa fresca da parte aérea, biomassa seca da parte aérea, biomassa seca da raiz, biomassa seca total, relação entre altura e diâmetro do colo e o índice de qualidade de Dickson. Os resultados evidenciam que a aplicação de fertilizante de liberação lenta leva a ganhos significativos de crescimento em ambas as espécies, sendo as melhores doses 6,68 a 5,54 kg m-3 para a espécie Anadenanthera peregrina, e 8,38 a 14,42 kg m-3 para Schinus terebinthifolius.

Effects of individual and combined metal foliar fertilisers on iron- and manganese-deficient Solanum lycopersicum plants

Using Fe- and Mn-deficient Solanum lycopersicum plants, we investigated the effects of Fe and Mn foliar fertilisers, either individually or combined, on plant biomass, leaf chlorophyll and metal micronutrient levels in leaves and roots. Plants were grown in hydroponics with different combinations of 0 or 45 μM Fe and 0 or 4.6 μM Mn. Foliar fertiliser formulations (9 mM FeSO4 and/or 3 mM MnSO4, supplemented with a surfactant) were applied in three consecutive doses. Fertilisation was applied to the first three leaf levels, while upper leaf levels were left untreated. Iron and Mn deficiency led to characteristic symptoms. Foliar treatments increased concentrations of Fe and Mn, biomass and chlorophyll in treated leaves, although re-greening was incomplete. Approximately 11–12 % of the Fe increase was in roots (likely mediated via phloem transport), but no Fe increase occurred in untreated leaves. Regarding Mn, a 2 % increase occurred in untreated leaves, but no increase occurred in roots. Iron fertilisation was effective not only in leaves treated with the fertiliser but also in roots, whereas Mn fertilisation had major effects on treated leaves and minor effects on untreated ones. The combined application of Fe + Mn was not detrimental to Fe- or Mn-deficient plants.

Explosions of ammonium nitrate fertilizer in storage or transportation are preventable accidents

Ammonium nitrate (AN) is a detonable substance which has led to numerous disasters throughout the 20th century and until the present day, with the latest disaster occurring on 17 April 2013. Needed safety lesson have not been learned, since typically each accident was viewed as a great surprise and investigations focused on finding some unique reason for the accident, rather than examining what is common among the accidents. A review is made of accidents which involved AN for fertilizer purposes, and excluding incidents involving ANFO or additional explosives apart from AN. It is found that, for explosions in storage or transportation, 100% of these disasters had a single causative factor—an uncontrollable fire. Thus, such disasters can be eliminated by eliminating the potential for uncontrolled fire. Two actions are required to achieve this: (1) adoption of fertilizer formulations which reduce the potential for uncontrolled fire and for detonation; and (2) adoption of building safety measures which provide assurance against uncontrolled fires. Technical means are available for achieving both these required measures. These measures have been known for a long time and the only reason that disasters continue to occur is that these safety measures are not implemented. The problem can be solved unilaterally by product manufacturers or by government authorities, but preferably both should take necessary steps.

Soybean plant growth study conducted using purified protein hydrolysate-based fertilizer made from chrome-tanned leather waste.

Leather processing discharges enormous amount of chrome containing leather solid waste which creates a major disposal problem. Chrome-tanned leather solid waste is a complex of collagen and chromium. The presence of chromium limits protein application in fertilizer industry. The purified protein hydrolysate with zero chromium could be used as a nitrogen source for fertilizer formulation. In this study, an attempt has been made to employ purified protein hydrolysate derived from chrome-tanned leather shavings (CTLS) in formulation of fertilizer. The formulated fertilizer (1–3 t ha(-1)) is employed as nitrogen source in production of soybean. Plant growth study demonstrates that formulated fertilizer dosage 3 t ha(-1) produced similar effects of commercial fertilizer-treated plants. Application of formulated fertilizer yielded higher seed in plant than commercial fertilizer.

Adubação, produtividade e rentabilidade da rotação entre soja e milho em solo com fertilidade construída

Resumo:O objetivo deste trabalho foi avaliar os efeitos da adubação sobre os teores de P e K, em solo com fertilidade construída, e identificar as doses de N, P e K necessárias para obtenção de maior rentabilidade com a rotação entre soja e milho nesses solos. O experimento foi realizado durante três safras, em propriedade com alto investimento tecnológico, em Latossolo Vermelho-Amarelo argiloso de Cerrado, com elevada fertilidade. Utilizou-se o delineamento de blocos ao acaso, com parcelas subdividas e três repetições. Os tratamentos consistiram de 0, 50, 100 e 150% das doses de fertilizantes NPK recomendadas na semeadura (parcelas) e das doses de KCl (soja) e N (milho) em cobertura (subparcelas). Mesmo após a colheita das três safras, os teores de P (Mehlich-1) se mantiveram inalterados no solo sem adubação. Além disso, não houve decréscimo na produtividade da soja na ausência de adubação. O milho, no entanto, foi mais sensível à redução de adubação, com o máximo retorno econômico obtido com 312 kg ha-1 do adubo formulado 10-32-10, e 263 kg ha-1 de ureia em cobertura. Solos com fertilidade construída demandam ajustes de manejo de adubação, para o uso eficiente dos fertilizantes em lavouras com alto investimento tecnológico.

Hydrogel/clinoptilolite nanocomposite-coated fertilizer: swelling, water-retention and slow-release fertilizer properties

Preparation of a new core–shell slow-release fertilizer formulation was conducted through the coating of commercial NPK fertilizer with hydrogel/clinoptilolite (Hyd/CL) nanocomposite. The Hyd/CL nanocomposite was prepared from free radical polymerization of sodium alginate, acrylic acid, acrylamide, and clinoptilolite zeolite. The uniform coating on the surface of the fertilizer granules was verified by scanning electron microscopy. The swelling kinetics as well as the water-retention property and water absorption rate of the prepared samples was studied. Furthermore, the release of fertilizer from Hyd/CL nanocomposite-coated fertilizer granules into soil showed that the Hyd/CL nanocomposite layer around the fertilizer granules caused the system to liberate the nutrient in a more controlled manner (lower than 57 % of loaded fertilizer on the 30 days) than that with the uncoated fertilizer. The overall results eventually suggested that the hydrogel nanocomposite designed in this work can be used as a coating on granular fertilizer compounds for application in agriculture due to its water-retention and slow-release properties.

Windrow co-composting of natural casings waste with sheep manure and dead leaves

After studying the waste management opportunities in small and medium companies of natural casings, composting has proved more viable and cost effective solution for the valorization of these types of waste, but its feasibility depends on the final product value. This paper investigated a pilot scale program for the windrow co-composting of natural casings waste with sheep manure and dead leaves incorporation. Processing, characterization and application of the final compost were described and the final compost was analyzed for pathogens, metals, nutrients, maturity, and agronomic parameters. The results showed that all test result levels were below the limits specified in the EPA regulations published in Title 40, Section 503, of the Code of Federal Regulations (40 CFR 503). Moreover, the agronomic value tests which include nutrients, organic matter, pH, electrical conductivity, etc. showed that the compost had high organic-matter content and low salt content, all of which indicate good compost characteristics. The ratio of nitrogen (N), phosphorus (P), and potassium (K), or NPK ratio, was measured at 1.6–0.9–0.7. Reported units are consistent with those found on fertilizer formulations.

Sequential Determination of 13 Elements in Complex Matrices by Stripping Voltammetry with Mixed Complexing Electrolytes

AbstractThis paper presents the determination of 13 elements in a simultaneous and sequential analysis using solochrome violet (SVRS), chloranilic acid (CA), diethylenetriaminepentaacetic acid (DTPA), dimethylglyoxime (DMG), and oxine as complexing electrolytes. The Methods were applied to determine Al3+, Fe3+, Mo6+, Zn2+, Cd2+, Pb2+, Cu2+, Ni2+, Co2+, Tl+, U6+, V5+, and Cr6+ in fertilizers, plant materials, and foodstuffs. The Method was found to be selective and accurate (82.13–119.03 %) for elemental analysis in complex matrices that were previously submitted to a total oxidative digestion step (calcination and wet digestion). Mutual interferences of the elements were systematically investigated. The Sequential Method could be useful for the routine quality control of foodstuffs and fertilizer formulations regarding mineral nutrients or contaminants.

Comparative Assessment of Cocoa Pod Husk Biochar Fortified with NPK Fertilizer Formulations on Kola Seedling Nutrient Uptake and Soil Properties in Ibadan, Nigeria

A greenhouse trial was carried out at Cocoa Research Institute of Nigeria, Ibadan in 2013 to evaluate the effect of cocoa pod husk (CPH) biochar fortified with NPK fertilizer formulations on kola seedling nutrient uptake and soil properties. The treatments consisted of a control, NPK (3 g) + Biochar (5 g), NPK (Liquid – 3 mls/L of water) + Biochar (5 g), Biochar (5 g), NPK (Solid-3 g), NPK (Liquid – 3 mls/L of water). The six treatments were replicated three times in a completely randomized design and data on nutrient uptake of kola seedlings and soil properties were taken for seven months. Results showed that all the fertilizers irrespective of rates of application and types of NPK formulations enhanced the nutrient uptake of kola seedlings relative to control. The leaf and root nitrogen uptake of kola seedlings was significantly (p<0.05) enhanced as a result of CPH biochar applied singly (T4) or in combination with NPK liquid fertilizer (T3) compared to when biochar was applied with NPK solid fertilizer. The leaf and stem P-uptake of Kola seedlings was not significantly influenced by CPH biochar and NPK fertilizer formulations. Conversely, the POriginal Research Article Ibiremo and Akanbi; IJPSS, 6(5): 303-309, 2015; Article no.IJPSS.2015.120 304 uptake of root of kola seedlings was significantly (p<0.05) improved as a result NPK (liquid) fertilizer compared to NPK (solid) applied alone. The pH of the soil was significantly (p<0.05) affected due to application of CPH biochar in combination with liquid NPK (T3) and CPH biochar alone (T4) compared to the control and NPK solid (T5). The exchangeable K in the soil was significantly (p<0.05) influenced as a result of CPH Biochar application and NPK fertilizer formulations. CPH biochar alone (T4) significantly (p<0.05) improved the exchangeable potassium in the soil compared to the control. The positive influence of CPH biochar applied either alone or in combination with NPK fertilizers on nutrient uptake of kola seedlings and soil nutrients indicated that integrated use of organic and inorganic fertilizers holds the ace for crop production and soil fertility management in Nigeria. Kola farmers across the growing regions have the privilege of using biochar fortified with NPK fertilizer (liquid) for improved productivity.

Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating

Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating

Encapsulated Urea-Kaolinite Nanocomposite for Controlled Release Fertilizer Formulations

Urea controlled release fertilizer (CRF) was prepared via kaolinite intercalation followed by gum arabic encapsulation in an attempt to reduce its severe losses associated with dissolution, hydrolysis, and diffusion. Following the beneficiation, the nonkaolinite fraction decreased from 39.58% to 0.36% whereas the kaolinite fraction increased from 60.42% to 99.64%. The X-ray diffractions showed that kaolinite was a major phase with FCC Bravais crystal lattice with particle sizes ranging between 14.6 nm and 92.5 nm. The particle size varied with intercalation ratios with methanol intercalated kaolinite &gt; DMSO-kaolinite &gt; urea-kaolinite (KPDMU). Following intercalation, SEM analysis revealed a change of order from thick compact overlapping euhedral pseudohexagonal platelets to irregular booklets which later transformed to vermiform morphology and dispersed euhedral pseudohexagonal platelets. Besides, dispersed euhedral pseudohexagonal platelets were seen to coexist with blocky-vermicular booklets. In addition, a unique brain-form agglomeration which transformed into roundish particles mart was observed after encapsulation. The nanocomposites decomposed between 48 and 600°C. Release profiles showed that 100% of urea was released in 97 hours from KPDMU while 87% was released in 150 hours from the encapsulated nanocomposite. The findings established that it is possible to use Pugu kaolinite and gum arabic biopolymer to prepare urea CRF formulations.

Evaluation of biodegradable polymers as encapsulating agents for the development of a urea controlled-release fertilizer using biochar as support material

Biochar constitutes a promising support material for the formulation of controlled-release fertilizers (CRFs). In this study we evaluated the effect of different polymeric materials as encapsulating agents to control nitrogen (N) leaching from biochar based CRFs. Nitrogen impregnation onto biochar was performed in a batch reactor using urea as N source. The resulting product was encapsulated by using sodium alginate (SA), cellulose acetate (CA) and ethyl cellulose (EC). Leaching potential was studied in planted and unplanted soil columns, monitoring nitrate, nitrite, ammonium and urea concentrations. After 90days, plants were removed from the soil columns and plant yield was evaluated. It was observed that the ammonium concentration in leachates presented a maximum concentration for all treatments at day 22. The highest concentration of N in the leachates was the nitrate form. The crop yield was negatively affected by all developed CRFs using biochar compared with the traditional fertilization.

Pelletization of composted swine manure solid fraction with different organic co-formulates: effect of pellet physical properties on rotating spreader distribution patterns

Introduction In Europe, because of the high production levels of livestock farming in general and pig farming in particular, animal waste management has become increasingly important to comply with the required lowering of livestock farming environmental pressure. Usually manures undergo solid/liquid separation, which generates one clarified liquid fraction and one nutrient-rich solid fraction suitable for in farm composting (both raw and in mixture with other bulking agents). This can be used to produce soil amendments, whose management can be further improved by pelletization that, against technological and environmental advantages, has the disadvantage of requiring a quite high energy input. Results Four different pelleted organic fertilizer formulations made of swine manure solid fraction (SMSF) composted both by itself and with sawdust (SMSF-SD), wood chips (SMSF-WC) and wheat straw were tested to highlight differences in physico-chemical and land distribution features. They were compared with two pelleted organic fertilizers ordinarily available at retailers. Results show that, as far as physical and chemical features are concerned, the greatest difference from the reference products used in this study is found in pellet size distribution after spreading since the disintegrating action of the rotating vanes does not affect the tested formulation with the same intensity as the commercial products. Distribution tests showed that SMSF-SD was the formulation with better longitudinal and transverse distribution, while SMSF was the one showing good transverse but poor longitudinal distribution.

Meticulous Overview on the Controlled Release Fertilizers

Owing to the high demand for fertilizer formulations that will exhaust the possibilities of nutrient use efficiency (NUE), regulate fertilizer consumption, and lessen agrophysicochemical properties and environmental adverse effects instigated by conventional nutrient supply to crops, this review recapitulates controlled release fertilizers (CRFs) as a cutting-edge and safe way to supply crops’ nutrients over the conventional ways. Essentially, CRFs entail fertilizer particles intercalated within excipients aiming at reducing the frequency of fertilizer application thereby abating potential adverse effects linked with conventional fertilizer use. Application of nanotechnology and materials engineering in agriculture particularly in the design of CRFs, the distinctions and classification of CRFs, and the economical, agronomical, and environmental aspects of CRFs has been revised putting into account the development and synthesis of CRFs, laboratory CRFs syntheses and testing, and both linear and sigmoid release features of CRF formulations. Methodical account on the mechanism of nutrient release centring on the empirical and mechanistic approaches of predicting nutrient release is given in view of selected mathematical models. Compositions and laboratory preparations of CRFs basing onin situand graft polymerization are provided alongside the physical methods used in CRFs encapsulation, with an emphasis on the natural polymers, modified clays, and superabsorbent nanocomposite excipients.

Strategies to produce commercial liquid organic fertilisers from “alperujo” composts

Abstract Composting is considered an economically-friendly procedure for producing commercial solid organic amendments and fertilisers from the two-phase olive mill waste (called “ alperujo ”: AL), main by-product of the Spanish olive oil industry. AL composts are characterized by a noticeable organic matter content, mainly of lignocellulosic nature, which determines their humic properties. In this study, we have assayed several extraction conditions in order to release commercial liquid organic fertilisers from AL composts. The following conditions were tested: extraction time, extraction temperature, heat (70 °C) time applied, extraction ratio, extractant agent and alkali concentration. Their effects on organic fraction (total organic, polyphenol- and carbohydrate-like carbons), nutrient concentration and extraction efficiency were evaluated. In general terms, an increase in the extraction time and the combined use of alkali and heat increased significantly the amount of organic carbon solubilised from the compost, affecting the nature of the alkali-soluble organic matter and even showing a chemical degradation of the humic fraction in some cases. The extraction ratio modified the concentration of the organic and inorganic fraction in the extracts, and also their polyphenol and carbohydrate content. The use of a 24 h extraction with 1 M KOH (1:4 or 1:5, extraction ratios) and heat (4 h at 70 °C) allowed us to extract the required amount of C and K from AL compost, being necessary an external source of N and P to complete the fertiliser formulations according to the current Spanish legislation for Organo-mineral Fertiliser production ( RD 506/2013, 2013 ).

Zinc fertilization influence on maize productivity and grain nutritional quality under integrated soil fertility management in Zimbabwe

Current efforts to promote integrated soil fertility management (ISFM) for improved productivity of staple cereal crops in sub-Saharan Africa have paid little attention to soil micronutrient deficiencies under smallholder farming. This has not only compromised yields, but also undermined the nutritional quality of harvested grains. To address this knowledge gap, a study was carried out over two cropping seasons in Hwedza district in eastern Zimbabwe to assess the added grain yield and nutritional benefits of zinc (Zn) fertilizer application to maize (Zea mays L.) under different ISFM options. In all cases, Zn application resulted in added maize grain and quality benefits. Application of Zn (11kgha−1) in combination with organic nutrient resources (5tha−1), and mineral fertilizers (90kg Nha−1 and 26kg Pha−1) gave the highest maize grain yields of up to 3.9tha−1; which translated to 1.3 times more yield than under sole mineral NPK fertilizers. In the subsequent season, there were significantly higher residual effects (2tha−1) from organic xZn combinations compared with sole mineral fertilizer treatments. Organic nutrient resources and Zn application significantly (P<0.05) influenced maize grain P and Zn concentration, with cattle manure consistently producing the highest grain P concentrations of 0.44%. Maize grain under combinations of mineral NPK, Zn and leaf litter gave the highest grain Zn concentration of up to 35mgkg−1. The Zn-based treatments increased grain Zn concentration and yield by 67 and 29%, respectively, indicating that there was much more benefit in grain quality than just yield after external Zn application. Combined organic resource and Zn fertilization also resulted in a significant build up of plant available soil P and ethylenediaminetetraacetic acid (EDTA) extractable Zn. Concentrations of 7.4mg Pkg−1 and 5.5mg Znkg−1 were measured after application of organics, compared with initial values of 5.2mgkg−1 and 1.15mgkg−1, respectively. It was concluded that benefits of ISFM options currently promoted in smallholder farming systems in Zimbabwe are constrained by soil Zn deficiencies. Combining these ISFM options with Zn fertilizer formulations increased yields and grain quality of the staple maize, enhancing scope for agronomic fortification of maize to enhance human nutrition.

Application Research of Slow-Release Fertilizer in Plant Camouflage

Plant camouflage is one of the camouflage methods, which is conducted by using of planting and collecting plant and changing color of plant to conceal targets. It can be used to camouflage relatively big permanent fixed targets in peace time and also to camouflage relatively big permanent fixed targets in peace time and also to camouflage relatively small fixed or moving targets. However, in recent years, with the natural disasters occurring alternately, plant camouflage can be destroyed easily, and it is difficult to rebuild in a short time. To improve the effect of plant camouflage, more fertilizers are required, which may become an environmental hazard, unless adequate technical and socioeconomic impacts are addressed. A multifunctional slow-release nitrogen fertilizer has been developed to improve fertilizer use efficiency and reduce environmental pollution. In this paper, a series of slow-release formulations of nitrogen fertilizer were developed on the basis of natural attapulgite clay, ethylcellulose film, and sodium carboxymethylcellulose/hydroxylethylcellulose hydrogel. The structural of the product were examined. The slow-release profiles of ammonium chloride, ammonium sulfate, and urea as nitrogen fertilizer substrates were determined in soil.

Phosphorus Diffusion from Fertilizer: Visualization, Chemical Measurements, and Modeling

Phosphorus (P) applied to soil as fertilizer moves away from the point of application mainly through diffusion. Sorption and precipitation reactions may reduce its mobility and availability to plants. Here, we developed a method to visualize diffusion of P from fertilizer in a simple and nondestructive way. A fertilizer granule is added in the center of a soil-filled Petri dish. After a given incubation time, a filter paper impregnated with Fe oxide acting as a P sink is placed on the soil surface. The P captured on the filter paper is visualized using a modified malachite green method, which creates a mirror image of the diffusion zone. The paper is scanned and analyzed using imaging software to quantify the extent and intensity of the diffusion zone. This method was applied to a range of fertilizer formulations in soils with contrasting properties. The extent of diffusion was also assessed through concentric sampling and chemical analysis of soil sections. The measured diffusion was compared with predictions of a numerical diffusion model. The method demonstrated the effects of soil properties and fertilizer formulation on P diffusion. The extent of diffusion strongly depended on soil properties, with least diffusion in soils rich in amorphous oxides and in calcareous soils. Results of the visualization method were in good agreement with chemical analyses and modeling results. This method allows easy comparison of fertilizer sources and enables a better understanding of the physicochemical processes affecting fertilizer P behavior at the soil-fertilizer interface.

FERTILIZER FORMULATION EFFECT ON PH OF FALLOW VERSUS PLANTED CONTAINER SUBSTRATE

From previous work testing the impact of 30 fertilizers on substrate pH, five fertilizer formulations that elicited the widest range of substrate pH biotic impacts during Salvia farinacea ‘Evolution White’ cultivation were chosen for a follow up study to determine the abiotic impact of these fertilizers on fallow substrate. A 3 sphagnum peat moss : 1 perlite substrate was formulated and adjusted to pH 5.6. Three sets of pots (14 cm diameter) were filled with substrate. Salvia plugs were installed in the first set for cultivation while the second set was left fallow followed by fertilization of both sets with 400 mL of fertilizer solution with each irrigation (each at 7 mmol nitrogen concentration and pH 4.2 ± 0.1) to bring them to approximately container capacity. The third set of pots (control) was left fallow and irrigated with 400 mL deionized water instead of fertilizer solution. When cultivated substrates dried to approximately 50% of container capacity, 200 mL of fertilizer solution was applied to sets one and two and 200 mL deionized water to set three for a total of 11 applications. Substrates were harvested after 3 and 6 weeks. The pH of control substrate was 5.69 for both harvests. For the first and second harvest, cultivated substrate pH ranged from 6.08 to 5.03 and 6.22 to 4.85, respectively, while pH values of fallow substrate that received fertilizer solutions ranged from 5.66 to 5.19 and 5.44 to 4.97, respectively. Contrary to the expected abiotic effect of these acidic fertilizer solutions, pH in the fertilized fallow pots increased or decreased in a similar but diminished fashion to the changes that occurred to the pH in the cultivated pots. These results suggested a biotic effect in the fallow substrates due possibly to microflora and nitrification and indicate the need to take into account a biotic effect of microbes when assessing the abiotic effect of fertilizer solutions on substrate pH.