Effect of the Concentration of Phosphorus on Growth and Nutrition of Leucospermum cordifolium ‘Flame Spike’

The aim of this study was to determine how phosphorus (P) concentration affects growth, concentration and distribution of nutrients in Leucospermum cordifolium ‘Flame Spike’ (Proteaceae). The trials were performed at the School of Agriculture (ETSIA) of the University of La Laguna (28° 28′ 43′′ N, 16° 19′ 7′′ W) with 64 plants (1-year-old) grown for 12 months in silica sand, fed with nutrient solutions containing different levels of P_i (5, 10, 15 and 20 mg L^?1). At 6, 9, and 12 months, whole plants were taken from each experimental unit and divided into root, stem (main, first, second, and third growth) and leaves (adult, first, second, and third growth), which were measured, weighed, and analyzed. The data enabled a nutritional diagnosis, including the limiting P concentrations and nutrient interactions. P concentrations above 5 mg L^?1 caused a reduction in growth, which in the third samples was significant (P < 0.05). Plants treated with 15 and 20 mg L^?1 P attained similar dry weights (P > 0.05). Some young leaves showed a certain degree of chlorosis, probably due to iron (Fe) deficiency. Fully developed young leaves (YFEL) were suitable for nutritional diagnosis of P, and the P concentration of the nutrient solution affected the foliar manganese (Mn) concentration. This latter factor was related to the zinc (Zn) concentration in the roots.     

Effect of Protease Treatment Before Hydrolysis with α-Amylase on the Rate of Starch and Protein Hydrolysis of Maize,Whole Sorghum,and Decorticated Sorghum

We studied the effect of sorghum decortication and protease treatment on starch hydrolysis before liquefaction with thermoresistant α-amylase and the generation of free amino nitrogen (FAN) in preparation for subsequent steps of ethanol production. A bifactorial experiment with a level of confidence of P < 0.05 was designed to study differences among maize, whole sorghum, and decorticated sorghum and the effectiveness of the protease treatment before starch liquefaction. Sorghum was decorticated 9.7% to remove most of the pericarp and part of the germ and increase starch concentration. Starch concentration increased in decorticated kernels, whereas total phenols, fiber, and fat decreased. The decorticated sorghum had significantly higher starch and protein hydrolysis compared with the whole kernel. Protease treatment before liquefaction improved the rate of starch hydrolysis, especially in mashes from whole and decorticated sorghums. Whole and decorticated sorghum hydrolyzates treated with protease contained ≈50% more reducing sugars than the untreated counterparts. Maize yielded hydrolyzates with the the highest amount of FAN, followed by decorticated and whole sorghums. The maize and both sorghum hydrolyzates treated with protease contained ≈60 and 30% more FAN compared with the untreated counterparts. Both sorghum decortication and protease treatments before hydrolysis with α-amylase are recommended to increase ethanol yields, save processing time (and therefore energy), and to produce mashes with higher FAN content, which is considered as an important yeast substrate.     

Effect of Zinc × Boron Interaction on Plant Growth and Tissue Nutrient Concentration of Corn

ABSTRACT

A pot experiment was conducted in a greenhouse on a calcareous soil (fine, mixed, mesic, Fluventic Haploxerepts) to study the interaction of zinc (Zn) and boron (B) on the growth and nutrient concentration of corn (Zea mays L.). Treatments consisted of a factorial arrangement of seven levels of B (0, 2.5, 5, 10, 20, 40, and 80 mg kg^{? 1}as boric acid), two sources of Zn [zinc sulfate (ZnSO₄ · 7H₂O) and zinc oxide (ZnO)], and three levels of Zn (0, 5, and 10 mg kg^{? 1}) in a completely randomized design with three replications. Plants were grown for 70 d in 1.6 L plastic containers. Applied Zn significantly increased plant height and dry matter yield (DMY) of corn. Source of Zn did not significantly affect growth or nutrient concentration. High levels of B decreased plant height and DMY. There was a significant B × Zn interaction on plant growth and tissue nutrient concentration which were rate dependent. In general, the effect of B × Zn interaction was antagonistic on nutrient concentration and synergistic on growth. It is recommended that the plants be supplied with adequate Zn when corn is grown in high B soils, especially when availability of Zn is low.     

Effect of Low‐Rate Commercial Humic Acid on Phosphorus Availability,Micronutrient Uptake,and Spring Wheat Yield

Abstract

A greenhouse study was conducted to determine the effects of low‐rate commercial humic acid (HA) on phosphorus (P), iron (Fe), and zinc (Zn) availability and spring wheat yields, in both a calcareous soil and a noncalcareous soil. In Phase I, soluble P concentrations were monitored at 1.9, 3.8, and 5.7 cm from a monoammonium phosphate (MAP) fertilizer band that had either been coated with one of two HA products at the equivalent of 1.7 kg HA ha^?1, a label rate, or left uncoated. Sampling occurred periodically up to 48 d after fertilizer application. In Phase II, uptake of P, Fe, and Zn and grain yield were measured in soils that had been fertilized with 7.5 or 25 kg P ha^?1, either coated with HA or left uncoated. In Phase I, only three significant differences (P=0.05) out of 66 comparisons were found in soluble P concentrations between HA and control treatments at time points ranging from 4 to 48 d after fertilization. In addition, no significant differences were found in nutrient uptake, shoot biomass, or grain yield between HA and control treatments. These greenhouse results suggest that low commercial HA rates (～1.7 kg HA ha^?1) may be insufficient to enhance spring wheat growth.     

Examining the Effects of the Destroying Ammunition,Mines, and Explosive Devices on the Presence of Heavy Metals in Soil of Open Detonation Pit: Part 1—Pseudo-total Concentration

This paper presents the results of determining the pseudo-total concentration of five heavy metals in the soil on which the destruction of ammunition, mines, and explosive devices is carried out by the method of open detonation. In the analyzed area, the concentrations of cadmium, lead, nickel, copper, and zinc were determined, while from the physical properties of the soil were determined the granulometric composition and the pH. The aim of the study is to determine the origin and total load on heavy metals and, based on that, to assess the dangers and impact of the site in terms of the soil pollution by heavy metals. In accordance with the regulations of Bosnia and Herzegovina, the results of the soil testing showed a significant load of copper (up to seven times) and cadmium (up to six times), and exceeding the allowed values for nickel and zinc in some places. Lead was the only metal whose concentration was within the maximum allowed and according to that the soil was classified as unpolluted. A sample of soil from the edge of the pit is the only sample in which all heavy metals, except Ni, were within the maximum allowable concentration. In regard to the concentration of the examined metals, the soil of the pit is classified as medium polluted from the aspect of copper, cadmium, and nickel and highly contaminated with zinc. The concentrations of copper and zinc in the examination area correspond to contaminated soil that represents ecological risk, which requires soil remediation.     

Effect of storage process on the sugars, polyphenols, color and microbiological changes in cracked Manzanilla-Aloreña table olives

The green cracked "seasoned" Manzanilla-Alore?a table olive is a specialty with a high demand when prepared from fresh fruits; however, when stored fruits are used, the product loses its green color, presents a brownish tone, and loses demand. Different alternative storage systems for preventing such changes and preserving the freshness of the fruits were studied, and their effects on sugar, polyphenol, color, and microbiological changes were analyzed. The application of two washing waters in the presence of different compounds before brining markedly decreased the sugar and polyphenol contents in the flesh, without negatively influencing the color; it also caused the inhibition of yeasts and lactic acid bacteria (except in treatments using sodium metabisulfite and saturated carbon dioxide (CO(2)) in the storage olive brines. Salicylic acid inhibited microbial growth during washings and storage. The best long-term color was achieved in the presence of sodium metabisulfite. A combination of two washing waters (containing 5% sodium chloride (NaCl) and 0.1% sodium metabisulfite or saturated CO(2)), followed by immersion of the fruits in 15% NaCl brine with 0.1% sodium metabisulfite or brine under saturated CO(2) added, led to the best storage conditions.     

Effect of High‐Molybdenum Compost on Soils and the Growth of Lettuce and Barley

A pot experiment evaluated the growth of lettuce (Lactuca sativa L.) and barley (Hordeum vulgar) and accumulation of molybdenum (Mo) in plants and soils following amendments of Mo compost (1.0 g kg^?1) to a Truro sandy loam. The treatments consisted of 0 (control), 12.5, 25, and 50% Mo compost by volume. The Mo compost did not affect dry‐matter yield (DMY) up to 25% compost, but DMY decreased at the 50% compost treatment. The 50% compost treatments increased the soil pH an average of 0.5 units and increased the nitric acid (HNO₃)–extractable Mo to 150 mg kg^?1 and diethylenetriaminepentaacetic acid (DTPA)–extractable Mo to 100 mg kg^?1 in the growth medium; the same treatment increased tissue Mo concentration to 569 and 478 mg kg^?1 in the lettuce and barley, respectively. Plants grown in the 25% compost produced about 55 mg kg^?1 of total Mo in the growth medium; this resulted in tissue Mo concentration of 348 mg kg^?1 in lettuce and 274 mg kg^?1 in barley without any phytotoxicity. Our results suggested that 55 mg Mo kg^?1 soil would be an appropriate limit for Mo loading of soil developed from compost additions, a value which is presently greater than the Canadian Council for Ministers of the Environment (CCME) Guidelines for the use of type B compost in Canada.     

Clay Addition to Sandy Soil Reduces Nutrient Leaching—Effect of Clay Concentration and Ped Size

Leaching of nutrients, particularly in sandy soil with low nutrient and water holding capacity (WHC), is a major threat to marine and fresh water pollution. Addition of clay soil to sandy soil could be an option to increase water and nutrient holding capacity of sandy soils, but the effect of clay soil addition may depend on the form in which the clay soil is added and the addition rate. Clay soil was added to sandy soil at rate of 10 or 20% (w/w) finely ground (<2 mm) or 2 and 5 mm peds with and without nitrogen (N) and phosphorus (P) fertilizer equivalent to 60 kg N ha^?1 and 15 kg P ha^?1. The clay sand mixture for each treatment was weighed (30 g) in cores with nylon mesh at the bottom. The soils were incubated at 80% WHC for 7 weeks. To obtain leachate, 20 mL reverse osmosis (RO) water was added every week to each core. Leachate was analysed for inorganic N, P, and pH. Soil was analyzed for N, P, and pH before and after the leaching. Clay addition significantly reduced the leaching of N and P compared to sandy soil alone, with greatest reduction by finely ground clay soil and least with 5 mm peds. Compared to sandy soil alone, 83% more N was retained in clay-amended soil and P retention was doubled. This study showed that addition of finely ground clay soil can substantially reduce N and P leaching and thereby increase fertilizer retention compared to sandy soil alone.     

Effect of the maturation process on the phenolic fractions, fatty acids, and antioxidant activity of the Chétoui olive fruit cultivar

Maturity is one of the most important factors associated with the quality evaluation of fruit and vegetables. This work aims to investigate the effect of the maturation process of the olive fruit on the phenolic fraction and fatty acid of irrigated Chétoui cultivar. The phenolic composition was studied by using reverse-phase high-performance liquid chromatography followed by LC-MS and GC-MS analyses and fatty acids by GC. Oleuropein was the major phenolic compound at all stages of ripeness. Unexpectedly, both phenolic compounds hydroxytyrosol and oleuropein exhibited the same trends during maturation. Indeed, the oleuropein levels decreased during the ripening process and were not inversely correlated with the concentrations of hydroxytyrosol. The antioxidant capacity of olive extracts was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and the beta-carotene linoleate model system. The IC 50 and AAC values of the olive extracts decreased from 3.68 to 1.61 microg/mL and from 645 to 431, respectively. There was a correlation between the antioxidant activity and the oleuropein concentration. The fatty acid composition was quantified in olive fruit during maturation and showed that fatty acids were characterized by the highest level of oleic acid, which reached 65.2%.     

Effect of isomorphic substitutions on the Mössbauer and magnetic parameters of goethite

The effect of the isomorphic substitutions in the goethite structure on its magnetic and Mössbauer parameters was studied. For this purpose, synthetic samples of Al-substituted goethite with particle sizes of 24–28 nm were obtained and studied by means of Mössbauer spectroscopy, X-ray diffractometry, electron microscopy, and magnetic measurements. It was found that an increase in the number of isomorphic ions in the structure of this iron hydroxide reduces its susceptibility, magnetization, and the effective magnetic field of the nucleus. In addition, the structural substitutions of aluminum for iron ions leads to a significant decrease in the temperature of the magnetic phase transition (the Neel temperature). The way to explain the experimental results on the basis of the Neel theory in the nearest-neighbor approximation was considered. The possibility to use the obtained results for studying the genesis of iron oxides and hydroxides in soils was shown by the example of East African laterites.     

Effect of crop load on hardiness,protein and amino acids content of apple flower buds at the wintering stage and the begining of the growth∗

The cold tolerance of flower buds of apple Malus domestica Borkh. ('Mclntosh'/M.7) declined during spring growth. The absence of fruit in the previous year increased the ability of the buds to withstand lower temperatures. All flower buds retained the capacity to tolerate freezing injury until first pink stage. The median lethal temperature (MLT) of the flower buds increased relatively throughout the sampling period. The flower buds of cropped trees were more susceptible to low temperature injury during spring at all stages of development. The flower buds of non‐cropped trees contained higher levels of hydrophilic and acidic amino acids from October until April, which may be related to their greater cold tolerance. A new nitrogen:protein conversion factor (5.51) was calculated based on total amino acid analysis which could be substituted for 6.25 as a means of estimating total protein content of apple flower bud tissue using the Kjeldahl method.     

PH—Postharvest Technology: Monitoring and Performance of a Commercial Grain Dryer

This paper presents detailed in situ experimental results for the performance of a commercial batch grain dryer under real operating conditions while drying barley. The distribution of key drying parameters of air temperature, relative humidity, airflow, grain moisture content, drying time and energy use are measured. For the two trials conducted, the overall cycle-averaged process thermal efficiency is 48·4 and 41·5%, respectively. This is achieved when the average initial moisture contents of the grain are, respectively, 15·7 and 17·2% and the highest plenum temperatures 41·4 and 34·0°C. During drying, unlike the stack-on temperatures, the exhaust air temperatures after the grain stack are fairly stable and only mildly affected by the variation of ambient conditions. After the initial heating period, the air enthalpy remains practically constant through the grain stack section. Close to the dryer centre, because of the presence of the auger, the air velocity is considerably lower than other parts of the dryer. The drying appears to be dominated by a drying front advancing through the grain stack. The reduction of grain moisture content is much faster during the last few hours of the drying process. The experiments highlight the importance of accurate measurement and representation of product moisture contents and airflow.     

Effect of Mussel��s Gender and Size on a Stress Response Biomarker

In mussels, stress signals such as heat, osmotic shock and hypoxia lead to the activation of the phosphorylated p38 mitogen activated protein kinase (pp38-MAPK). This stress activated protein has been efficiently used as a biomarker to several natural and anthropogenic stresses. However, what has not been tested is whether differences in gender or size can affect the response of this biomarker. The present study tested whether there was variation in the expression of pp38-MAPK in mussels Perna perna of different gender and size classes when exposed to natural stress conditions, such as air exposure. The results show that gender does not affect the expression of pp38-MAPK. However, size does have an effect, where mussels smaller than 6.5 cm displayed significantly (p?<?0.05) lower levels of pp38-MAPK when compared to those larger than 7 cm. Mussels are one of the most used bioindicator species and the use of biomarkers to determine the health status of an ecosystem has been greatly increasing over the years. The present study highlights the importance of using mussels of similar size classes when performing experiments using stress-related biomarkers.     

Effect of Salinity and Some Chemical Properties of the Under‐ and Intercanopy Soils on Range Plants in a Dry Region of Southern Iran

Abstract

The present study was conducted in a dry region in southern Iran to evaluate the effects of different Atriplex species on the salinity, soluble ions, and some of the other chemical properties of under‐ and intercanopy soils. The research region was divided into five separate sites with vegetation cover of the range plants Atriplex lentiformis, A. nummularia, and A. halimus (all newly introduced species) and A. leucoclada and Salsola rigida (both native species). Four 1‐kg soil samples (from under‐ and interspaces of the canopy of tested plants, each in two depths of 0–10 and 10–40 cm, were taken from each of the plant sites and analyzed for different determinations. The study was conducted as a factorial experiment in a complete random design with six replicates.

Regardless of distance and depth, different plant species resulted in different salinity (based on the EC values of saturation paste) and soluble cation contents in the tested soils. The results showed that the increase in EC values were associated with decreases in pH values of the tested soils.

The SAR values followed exactly the same pattern as EC values and Na⁺ concentrations. In the case of soluble anions, the Cl^? contents followed exactly the same pattern as the EC values of the tested soils, which indicates that the salts are predominantly chlorides of various cations (especially Na⁺). The OM and total nitrogen (N) contents of the undercanopy were greater than those of the interspace and those of the surface layer were greater than those of the sublayer. Moreover, although the phosphorus (P) and potassium (K) contents of undercanopy and interspace were not significantly different from each other, the P and K contents of the surface layer were greater than those of the subsurface layer. As seen from the results, except for the effect of depth of Mn contents and the interactive effect of distance and depth on Fe contents, neither the single effects (other than plant species) nor the interactive effects were significant on microminerals of the tested soils.

Moreover, copper (Cu) was particularly antagonistic toward iron (Fe), manganese (Mn), and zinc (Zn).     

Effect of the substrate concentration and water activity on the yield and rate of the transfer reaction of β-galactosidase from Bacillus circulans

Prebiotic galactosyl oligosaccharides (GOS) are produced from lactose by the enzyme β-galactosidase. It is widely reported that the highest GOS levels are achieved when the initial lactose concentration is as high as possible; however, little evidence has been presented to explain this phenomenon. Using a system composed of the commercial β-galactosidase derived from Bacillus circulans known as Biolacta FN5, lactose and sucrose, the relative contribution of water activity, and substrate availability were assessed. Oligosaccharide levels did not appear to be affected by changes in water activity between 1.0 and 0.77 at a constant lactose concentration. The maximum oligosaccharide concentration increased at higher initial concentrations of lactose and sucrose, while initial reaction rates for transfer increased but remained constant for hydrolysis. This suggests that the high oligosaccharide levels achieved at the raised initial saccharide concentration are due to increases in reactions that form oligosaccharides rather than decreases in concurrent reactions, which degrade oligosaccharides. There were different effects from changing the initial concentration of lactose compared to sucrose, suggesting that the ability of lactose to act as a donor saccharide may be more important for increasing maximum oligosaccharide concentrations than the combined ability of both saccharides to act as galactosyl acceptors.     

Does the Ammonium Fixation Capacity of Soils Have a Significant Effect on the Nitrogen Nutrition of Wheat?

Pot experiments were conducted on three soils differing in their ammonium (NH₄ ⁺) fixation capacity [high = 161 mg NH₄-nitrogen (N) kg^?1 soil; medium = 31.5 mg NH₄-N kg^?1 soil; and no = no NH₄-N was additionally fixed], and the effect of N fertilizer forms and doses on wheat (Triticum aestivum L.) was investigated. Grain yields responded to almost all forms of N fertilizer with 80, 160, and 240 kg N ha^?1 in the high, medium, and no NH₄ ⁺ fixing soil process, respectively. Agronomic efficiency of applied N fertilizers was significantly greater in the no NH₄ ⁺ fixing soil. Thousand grain weights (TGW) of wheat grown on the high and medium NH₄ ⁺ fixing soil decreased with increasing N. Grain protein increased with increasing NH₄ ⁺ fixation capacity. Nitrogen doses and the forms of N fertilizers affected grain protein at a significance level. The combination of urea + ammonium nitrate (NH₄NO₃) was most effective in increasing grain protein content.     

Effects of Arsenic‐Contaminated Irrigation Water on Growth,Yield, and Nutrient Concentration in Rice

Abstract

A study was undertaken to determine the effects of different concentrations of arsenic (As) in irrigation water on Boro (dry‐season) rice (Oryza sativa) and their residual effects on the following Aman (wet‐season) rice. There were six treatments, with 0, 0.1, 0.25, 0.5, 1, and 2 mg As L^?1 applied as disodium hydrogen arsenate. All the growth and yield parameters of Boro rice responded positively at lower concentrations of up to 0.25 mg As L^?1 in irrigation water but decreased sharply at concentrations more than 0.5 mg As L^?1. Arsenic concentrations in grain and straw of Boro rice increased significantly with increasing concentration of As in irrigation water. The grain As concentration was in the range of 0.25 to 0.97 µg g^?1 and its concentration in rice straw varied from 2.4 to 9.6 µg g^?1 over the treatments. Residual As from previous Boro rice showed a very similar pattern in the following Aman rice, although As concentration in Aman rice grain and straw over the treatments was almost half of the As levels in Boro rice grain. Arsenic concentrations in both grain and straw of Boro and Aman rice were found to correlate with iron and be antagonistic with phosphorus.     

The Effect of the Ionic Strength of Nutrient Solution on Gas Exchange,Ionic Concentration and Leaf Biomass of Annona emarginata (Schltdl.) H. Rainer Variety ‘Terra-Fria’ Seedlings

The present study aimed to test the hypothesis that different levels of the availability of mineral nutrients from Hoagland and Arnon's nutrient solution no. 2 affect the photosynthesis, ionic concentration and biomass production in seedlings of Annona emarginata (Schltdl.) H. Rainer variety ‘terra-fria’. Seedlings were grown in a hydroponic setting with 100% ionic strength and with ionic strength reduced to 75%, 50%, and 25%. Ionic strengths intermediate resulted in higher rates of carbon net assimilation and plants grown under these conditions increased biomass as well ionic concentrations of calcium, magnesium and sulfur. The ‘terra-fria’ plants with nutrient solutions of 50% and 75% ionic strength exhibited higher ionic concentrations, instantaneous carboxylation efficiency and biomass production. It can be concluded that the ‘terra-fria’ does not require the maximum mineral nutrients availability from Hoagland and Arnon's nutrient solution to achieve high primary productivity and intermediate ionic strengths can even reduce the time required for rootstock formation.