Use of Treated Wastewater as Fertilization and Irrigation Amendment in Pot-grown Processing Tomatoes

ABSTRACT

Plants of tomato cultivar ‘TITANO M’ were grown under glasshouse conditions, in plastic pots filled with the upper (Ap, Soil A) and the underlying horizons (Bt, Soil B) of an Alfisol from central Greece in a randomized complete block design. Four treatments were utilized: no fertilization and irrigation with distilled water (C), irrigation with wastewater without fertilization (W), complete fertilization (110 kg N ha^?1, 150 kg P₂O₅ ha^?1, 150 kg K₂O ha^?1) and irrigation with distilled water (CF), complete fertilization and irrigation with wastewater (WF) each replicated four times. The results showed that wastewater significantly increased electrical conductivity (EC), exchangeable sodium percentage (ESP), exchangeable magnesium (Mg), and extractable zinc (Zn). A three-fold increase of above ground biomass (AGB) compared to C treatment was recorded in Soil A. Photosynthates allocation to AGB and water use efficiency (WUE) were promoted by effluent application. Wastewater could be a water source for agriculture under water limited conditions substituting partially for inorganic fertilization.     

EFFECT OF SALINIZATION OF SOIL ON GROWTH,WATER STATUS AND NUTRIENT ACCUMULATION IN SEEDLINGS OF ACACIA AURICULIFORMIS (FABACEAE)

Greenhouse experiments were conducted to assess the effects of salinization of soil on emergence, growth, water status, proline content, and mineral accumulation of seedlings of Acacia auriculiformis A. Cunn. ex Benth. (Fabaceae). Sodium chloride (NaCl) was added to the soil and salinity was maintained at 0.3, 3.9, 6.0, 7.9, 10.0, 12.1, and 13.9 dS m^?1. Salinity caused reduction in water potential of tissues, which resulted in internal water deficit to plants. Consequently, seedling growth significantly decreased with increase in soil salinity. Proline content in tissues increased with increase in salinity. Potassium and sodium content significantly increased in tissues as salinity increased. Nitrogen content significantly increased in tissues with salinization of soil. Phosphorus, calcium and magnesium content significantly decreased as salinity increased. Changes in tissues and whole-plant accumulation patterns of other nutrients, as well as possible mechanisms for avoidance of sodium toxicity in this tree species in response to salinity, are discussed.     

INFLUENCE OF ELEVATED PHOSPHORUS LEVELS IN NUTRIENT SOLUTION ON MICRONUTRIENT UPTAKE AND DEFICIENCY SYMPTOM DEVELOPMENT IN STRAWBERRY CULTURED WITH FERTIGATION SYSTEM

The relationship between the total amount of micronutrients absorbed by the above-ground plant tissue and the occurrence of visible micronutrient deficiency symptoms in two strawberry cultivars as influenced by elevated phosphorus (P) levels in fertigation solution was investigated. The plants were cultured with a fertilizer solution containing 0, 0.5, 1, 2, 4, or 6 mM P and tissue nutrient content were determined at 120 days after transplanting. Young leaves of the plants grown with nutrient solution P levels higher than 4 mM and 2 mM, respectively, in ‘Keumhyang’ and ‘Seonhong’, developed interveinal chlorosis. Tissue concentrations (mg·kg^?1 dry weight) of metallic micronutrients [iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn)] in both cultivars did not decrease, but the total amount absorbed by the aboveground plant tissue decreased in the treatments in which nutrient deficiencies were observed. These results indicate that total amount of micronutrients is a better indicator of P-induced micronutrient deficiency.     

Effects of Nickel on Growth and Composition of Metal Micronutrients in Barley Plants Grown in Nutrient Solution

Abstract

A hydroponic experiment was conducted in a phytotron at pH 5.5 to study the effects of nickel (Ni) on the growth and composition of metal micronutrients, such as copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), of barley (Hordeum vulgare L. cv. Minorimugi). Four Ni treatments were conducted (0, 1.0, 10, and 100 μM) for 14 d. Plants grown in 100 μM Ni showed typical visual symptoms of Ni toxicity such as chlorosis, necrosis of leaves, and browning of the root system, while other plants were free from any symptoms. Dry weights were the highest in plants grown in 1.0 μM Ni, with a corresponding increase in the chlorophyll index of the plants, suggesting that 1.0～10 μM Ni needs to be added to the nutrient solution for optimum growth of barley plants. The increase of Ni in the nutrient solutions increased the concentrations of Cu and Fe in roots, while a decrease was observed in shoots. The concentrations of Mn and Zn in shoots and roots of plants decreased with increasing Ni supply in the nutrient solution. Shoot concentrations of Cu, Fe, Mn, and Zn in plants grown at 100 μ M Ni were below the critical levels for deficiency. Plants grown at 1.0 μ M Ni accumulated higher amounts of Cu, Fe, Mn and Zn, indicating that nutrient accumulation in plants was more influenced by dry weights than by nutrient concentrations. The translocation of Cu and Fe from roots to shoots was repressed, while that of Mn and Zn was not repressed with increasing Ni concentration in the nutrient solution.     

Chloroform-labile trace elements in soil via fumigation-extraction: Steps towards the soil microbial ionome beyond C:N:P

Secondary and trace elements may be limiting soil microbial functioning, albeit microbial demand and content remain largely unknown and methods for their in situ detection are limited. Thus, the objective of the present study was to take the first step towards the method development for the assessment of the soil microbial ionome, that is, the elemental composition of soil microbial communities. Chloroform (CHCl₃) fumigation extraction was used for the detection of microbial CHCl₃-labile secondary and trace element concentrations in soils. The suitability of two extractants (NH₄NO₃, CaCl₂) for the quantification of CHCl₃-labile concentrations of phosphorus, sulphur, potassium, sodium, and magnesium, as well as selenium, iron, zinc, manganese, copper, cobalt, nickel, molybdenum, vanadium, boron, silicon, barium, arsenic, and cadmium, were tested in six agricultural soils. Additionally, three soil to extractant ratios (1:5, 1:10, and 1:20) and two extraction durations, 1 or 2 h, were tested in a subset of two soils. Out of the two extractants tested, 0.01 M CaCl₂ was found to be the best-suited extractant. For CaCl₂, a soil-to-extractant ratio of 1:20 with an extraction time of 1 h was best for the majority of elements in the two soils tested. In a limited number of agricultural soils, we were able to show that CHCl₃ fumigation extraction can successfully be applied to the elements phosphorus, sulphur, potassium, sodium, magnesium, zinc, manganese, copper, nickel, vanadium, boron, silicon, and barium to yield a CHCl₃-labile element fraction. Conversion values to microbial biomass, accounting for elements contained in the cell envelope components, which are mostly not extractable, and to account for adsorption to soil colloids during extraction are yet to be determined in a larger variety of soils. To overcome some of the limitations of the fumigation extraction approach for secondary and trace elements, a pre-extraction step may provide a suitable solution.     

Micronutrient Contents of a Revegetated Saprolite Exposed by Excavation of an Oxisol

Soils of the Brazilian Cerrado biome have been found to be deficient in copper (Cu) and zinc (Zn). In this area, an Oxisol was deeply excavated in 1962 during the construction of a hydroelectrical plant, and the exposed saprolite material was abandoned, without any reclamation measures. The abandoned land was a harsh environment for plant growth, and the secondary vegetation has not recovered. A field trial was established in 1992 to assess the effects of different grass species and lime amendments on soil reclamation at the degraded site. In 2011 soil samples were collected at three depths (0–10, 10–20, and 20–40 cm) from vegetated and bare plots over tilled saprolite, from an untreated area of the saprolite, and from an Oxisol under native forest, used as external reference. Nineteen years after the reclamation effort was begun, the organic carbon (OC) content of the restored saprolite still was much lower than that of the Oxisol under natural vegetation. The undisturbed Oxisol was deficient in extractable Cu (0.16–0.10 mg kg^?1) and Zn (0.10–0.02 mg kg^?1) and exhibited rather low concentrations of extractable iron (Fe; 5.24–1.47 mg kg^?1) and manganese (Mn; 3.21–0.77 mg kg^?1). However, the saprolite under reclamation showed even lower levels of these elements compared to the native forest soil. In the natural soil, OC, N, extractable Fe, Mn, and Cu showed stratification, but this was not the case for extractable Zn. Although the reclaimed saprolite still was far from predisturbance conditions, the revegetation treatments promoted recovery of OC, N, Fe, Mn, and Cu at the surface layers, which resulted in incipient stratification. Extractable Fe, Mn, and Cu were correlated to OC, whereas no association between Zn and OC was detected. Our results also suggest that reclamation of the excavated saprolite may be constrained by micronutrient deficiencies and mostly by the extremely low levels of Zn and Cu.     

县域土壤有效态微量元素的空间变异特征及影响因素——以徐水县为例

以徐水县土壤有效态铜(Cu)、锌(Zn)、铁(Fe)、锰(Mn)为研究对象,利用GIS与地统计学相结合的方法,分析了4种微量元素的空间变异特征及影响因素。结果表明:4种有效态微量元素含量在空间上都属于中等程度变异;4种微量元素的块金效应值在12.21%~49.97%之间,其中Cu和Fe具有强烈的空间相关性,Zn和Mn具有中等的空间相关性。Cu和Mn在空间分布上呈现连续性,而Zn和Fe大体呈现岛状分布;除有效铜平均含量处于高含量水平,其它微量元素平均值均处于中含量水平;相关性分析显示除Fe对部分养分的正相关性不强外,Cu、Zn、Mn均与土壤养分呈极显著的正相关性;土壤p H值与4种微量元素均呈负相关性,其中Fe呈极显著的负相关性。     

Response of wheat seedlings to Mn‐lignosulfonate adhered to granular NPK

Manganese (Mn) deficiency is a widespread crop micronutrient disorder. The aim of this work was to evaluate two NPK fertilizers coated with Mn that eliminate the specific labor cost for applying Mn and that allow the correction of Mn deficiency in wheat (Triticum aestivum L.). Two Mn sources [MnSO₄ and Mn‐lignosulfonate (MnLS)] were compared as NPK coatings at doses of 0.1, 0.3, and 1.0% (w/w) in hydroponic, perlite, and soil pot cultures under growth chamber and greenhouse conditions with wheat to evaluate the effects on dry matter production and Mn concentrations. For the NPK+MnLS product, 52–63% of the total Mn remained in solution at calcareous conditions. However, the NPK+MnSO₄ product was able to maintain only 14–25% of the total Mn added in solution. As expected, the MnLS product resulted in higher Mn concentrations in shoots than the MnSO₄ product due to the Mn complexation by lignosulfonate which preserved Mn from precipitation and maintained it available for plants. In the experiment with perlite as growth substrate, at low Mn dose (0.1% Mn) a similar Mn concentration in wheat shoots was found (57 mg kg^?1 DW for the MnSO₄ coating versus 72 mg kg^?1 DW for MnLS coating), but at the highest dose (1.0% Mn) the NPK+MnLS showed a significant increase in shoot Mn concentration (167 versus 132 mg kg^?1 DW). Soil application of coated NPK products showed similar Mn concentrations in shoots with both Mn sources (29–37 mg kg^?1 DW), except for the NPK+MnSO₄ (0.1%) treatment (only 18 mg kg^?1 DW). Based on the recommended Fe/Mn values (Fe : Mn ratio = 1.5–2.5) given in the literature for plants with a correct nutrition, only the NPK+MnLS (0.3%) fulfilled this ratio (Fe : Mn = 2.5).     

Biomass Yield and Nutrients Concentration in Shoot Dry Weight of Winter Cover Crops for No-Tillage System

The aim of this study was to identify the cutting time for winter cover crops used as green manure in no-tillage systems that results in the highest dry weight yield (DWY) and nutrient accumulation. We tested Avena strigosa, Secale cereale, Vicia sativa, Raphanus sativus, and Lupinus albus, in five management times, determining the fresh weight yield (FWY), DWY, and the chemical composition of the shoot tissue. The highest FWY was obtained using R. sativus and L. albus. At 145 days after sowing; these species also had the highest DWYs, over 15 t ha^?1. L. albus and S. cereale had the highest carbon to nitrogen (C:N) ratio (60:1). The nutrient content of most crops decreased over time. However, the accumulation of nutrients increased over time, especially for R. sativus. L. albus had the highest level and manganese (Mn) accumulation, while the zinc (Zn) and cooper (Cu) accumulation was highest in A. strigosa, and that of boron (B) was highest in S. cereale. Thus, R. sativus provided the best soil cover among the species tested, due to its high biomass yield and greater nutrient cycling.     

Copper micronutrient fixation kinetics and interactions with soil constituents in semi-arid alkaline soils

This study examined the fixation pattern and kinetics of plant-available [diethylene triamine pentaacetic acid (DTPA)-extractable] copper (Cu), as well as basic soil properties that influence Cu availability in selected semi-arid soils. Soil samples from six different series were used and data obtained from Cu extraction experiments fitted to various kinetic models. Soils were also characterized for a suite of chemical and physical properties. The majority (80%) of the plant-available Cu fixed over the experimental period of 90 d occurred within the first 14 d. The amount of plant-available Cu fixed within the first 14 d tended to be influenced by the combination of organic matter (OM) and pH. The total amount of Cu fixed at the end of the experimental period of 90 d was influenced by pH and a combination of pH and calcium carbonate. The fixation of plant-available Cu over the experimental period was better described by the power function model [R² = 0.90, Standard Error (SE) = 0.099] but poorly by the other models (R²: 0.58 to 0.59), while reactions within the first 35 d were better described by the second-order model (R² = 0.98, SE = 0.008), suggesting a different fixation pattern. Findings from this study provide a basis for a more mechanistic approach to evaluating and comparing the fixation of Cu micronutrient compounds in these semi-arid soils for more scientific management decision making.