Plant Fertigation Research Articles

Anthroponics: Application and effects on growth of parsley, rhipsalis, coriander, and basil fed with urine fertiliser

Urine has emerged as a promising nutrient-rich waste stream suitable for plant fertigation. Biological nitrification in a membrane bioreactor offers an effective method for producing liquid fertiliser from urine, extracting essential nutrients into a final product. Despite the increasing interest in hydroponics and urban horticulture, research exploring the efficacy of urine-derived fertilisers remains scarce. This study employed three growing systems, including nutrient film technique open channels in outdoor setup, pot-drench under glasshouse conditions, and deep-water culture (DWC) under laboratory conditions to investigate the efficiency of urine-derived fertiliser compared to commercial fertilisers. The results demonstrated comparable growth responses in parsley, rhipsalis, coriander, and basil, as demonstrated by the analysis of several parameters including biomass, stem numbers and length, and nutritional composition in shoots and roots. In conclusion, urine-derived fertilisers showed promising potential as a sustainable alternative to synthetic fertilisers, laying the foundation for the development of a circular economy of nutrients in agriculture.

Specific energy analysis of using fertilizer-based liquid desiccants to dehumidify indoor plant environments

Controlling humidity in indoor plant environments is crucial to plant growth, but traditional dehumidification methods can be energy intensive. In this study, we evaluate the energy efficiency of a novel dehumidification concept that uses cold concentrated fertilizer solution as a liquid desiccant agent. This closes the water cycle by recovering water vapor for plant fertigation, and eliminates the need for energy-intensive desiccant regeneration. A theoretical transport model is used to conduct a parametric analysis of the specific energy performance of the system in response to desiccant temperature and other operating conditions. Specific energy of dehumidification is defined here as the ratio of the cooling load to the water vapor removal. Minimum specific energy results between 0.16 and 0.24 Wh/g are achieved at liquid desiccant temperatures between 7 and 14 °C. These results compare very favorably with other dehumidification technologies on the market, and satisfy new energy efficiency standards for indoor plant cultivation. The vapor flux associated with the minimum specific energy ranged from 1.2 to 1.6 g/m2/h. Controlling liquid desiccant temperature is shown to be critical to achieving high dehumidification rates at optimal specific energies. These encouraging results suggest that future research and development along this track can contribute to energy efficient greenhouse cultivation for sustainable food production.

Microcontroller-based Fertigation Farming Automation System

Fertigation is a technique that combines plant fertigation and irrigation that becomes most used by the commercial farmers as well as home growers. However, fertigation systems required a constant water supply and the exact amount of nutrient that plant needed as it changes depending on their growth. The paper aims to research, create, built, test and implement an automatic mixing fertilizer by implementing Total Dissolved Solids (TDS) monitoring system according to the plant’s nutrient level needed. It is also exploring the potential of optimum water usage by constructing an automatic timer for watering the plants according to the routine schedule. The system used an Arduino UNO R3 as a microcontroller. TDS sensor sense and measure the dissolved solids in a nutrient solution which gives information on the number of nutrients or impurities in TDS value. In an automatic watering system, the pump is running according to the timer set by a microcontroller. The frequency of distribution and the concentration of the solution depends on the weather conditions and the level of the crop. Hot weather requires more amount and frequency of fertilizer but in dilute solution. As such, this system has demonstrated a cost-effective, sustainable, eco-friendly, and safe environment as a result it will produce fresh and healthy plants that can give benefits to living things.

Effectiveness of enriching lettuce with iodine using 5-iodosalicylic and 3,5-diiodosalicylic acids and the chemical composition of plants depending on the type of soil in a pot experiment

Iodine is a beneficial element for humans, animals and plants. This study was a comparison of the effectiveness of iodosalicylate uptake by lettuce. The experiment included two sub-blocks: organic soil and mineral soil with the addition of the same fertigation of plants (8 times every 7 days) with 10 µM solutions (100 mL/per one plant/one application) of potassium iodate (KIO3), salicylic acid (SA) alone or together with KIO3, 5-iodosalicylic acid (5-ISA) or 3,5-diiodosalicylic acid (3,5-diISA). None of the tested iodine compounds negatively affected the yield of lettuce. When growing plants on mineral soil, plants accumulated more iodine in the leaves than plants grown on peat substrate. The use of 5-ISA allowed for achieving better efficiency of plant biofortification in iodine than the application of KIO3 and 3,5-diISA. The type of soil significantly modified the chemical composition of lettuce.

Ammonium to Total Nitrogen Ratio Interactive Effects with Salinity Application on Solanum lycopersicum Growth, Physiology, and Fruit Storage in a Closed Hydroponic System

Using high-salinity water for plant fertigation may have negative consequences for plant growth, overall yield and crop quality. In the present study, the effects of NaCl-salinity in conjunction with three different ammonium to nitrate ratios (Nr) on tomato (Solanum lycopersicum Mill.) plant growth, nutritional status, yield, fruit quality and postharvest storage were examined. The electrical conductivity (EC) was increased by adding NaCl into the nutrient solution and three different Nr ratios were applied, Nr0.05, Nr0.10 and Nr0.15, while the other macronutrient and micronutrient concentrations were constant in all treatments. The EC of the nutrient solution supplied to the plants was 2.2 mS cm−1 at the low salinity treatments and 7.5 mS cm−1 at the high salinity treatments. Increased salinity resulted in decreased plant growth factors and fruit yield, despite the Nr. An increased Nr reduced the pH value of the nutrient solution, while the fruits of the plants cultivated under high salinity obtained reduced Ca, K, Mg, P and N content. Reduced Ca content can lead to blossom end rot disorder and this was evidenced on tomato cultivation under high salinity. However, in the present study, this disorder appeared at the very late stages and did not affect the marketability of the fruits. On the other hand, both salinity and Nr0.15 increased fruit firmness at harvest or following storage, while citric acid, total soluble solid and vitamin C contents were also increased by salinity. Total phenols were increased by salinity at harvest, and lycopene and β-carotene content were increased by salinity at harvest and/or following storage at 12 °C or 25 °C. Salinity enhances fruit quality and improves the organoleptic characteristics of the crop, while an appropriate Nr ratio may restrict the detrimental effects of salinity on the nutritional status of plants by regulating the pH in hydroponic systems.

Effects of 24-epibrassinolide on plant growth, antioxidants defense system, and endogenous hormones in two wheat varieties under drought stress.

Drought stress is a major limitation in enhancing agricultural productivity to fulfill the food demand for the world's population. Fertigation of plants with a variety of biochemicals is being used to create drought resistance in wheat; however, the previous work has been limited in addressing these issues in plants at different growth stages. Therefore, a greenhouse study was conducted to ameliorate the drought stress in two wheat varieties (Chakwal-50 and Faisalabad-2008) by foliar application of 24-epibrassinolide (EBL). It was evident that drought stress had a negative effect on the growth, photosynthesis, and yield of wheat plants. EBL significantly enhanced the plant growth both under optimal and drought conditions. EBL improved the plant height, spike length, and the dry weights of roots, shoots, and grains as compared to control. Furthermore, the foliar application of EBL positively enhanced the osmolyte accumulation, increased the amounts of photosynthetic pigments, and improved the gas exchange parameters. The EBL minimized the oxidative stress by reducing electrolyte leakage, malondialdehyde, and hydrogen peroxide contents whereas it enhanced the activities of antioxidant enzymes, such as catalase, superoxide dismutase, and peroxidase under drought stress. The EBL significantly improved the level of stress hormones, such as abscisic acid, indol acetic acid, and cytokinin under drought stress. The growth response of Chakwal-50 was higher than that of Faisalabad-2008 when exposed to EBL under drought stress. Overall, the EBL plays a major role in the enhancement of growth, biomass, yield, and decrease in oxidative damage in wheat under drought conditions, however; field investigations with different doses of EBL are needed before any further recommendation.

Impact of Mother Plant Saline Stress on the Agronomical Quality of Pepper Seeds

Seed quality has been an important factor in achieving high germination and uniform growth rates in agricultural crops. Meanwhile, pepper plants are moderately sensitive to salt stress at electrical conductivity (EC) in the nutrient solution in the range of 1.2–3.0 dS m−1. We are unaware of any studies regarding the effects of mother plant saline stress on the agronomical quality of pepper seeds. We assessed the effects of three levels of electrical conductivity of the nutrient solution used for mother plant fertigation (2.2, 3.5, and 4.5 dS m−1) on the agronomical quality of pepper seeds (Capsicum annuum L. var. California Wonder). We have analyzed the following seed quality traits: (1) size and weight of seeds and number of seeds per fruit, (2) seed germination and vigor, and (3) chemical composition and histological features of mature seeds. The electrical conductivity treatment of 3.5 dS m−1 caused a statistically significant reduction in the seed size and vigor, as well as partial histological damage to seed endosperm. Moreover, the electrical conductivity treatment of 4.5 dS m−1 caused further reduction in the seed agronomical quality and generalized histological damage to seed endosperm. The electrical conductivity of the nutrient solution used for the fertigation of mother pepper plants should be below 3.5 dS m−1. Future studies should be performed to better gauge the effect of nutrient solutions with electrical conductivity in the range of 2.2–3.5 dS m−1 on the seed quality traits.

Interactive effects of salinity and silicon application on Solanum lycopersicum growth, physiology and shelf-life of fruit produced hydroponically.

Using water with high salinity for plant fertigation may have detrimental effects on plant development and total yield and on the quality of the crop produced. As a possible means to alleviate the negative effects of salinity, silicon (Si) can be incorporated in the nutrient solution supplied to plants. In the present study, hydroponically grown tomato (Solanum lycopersicum Mill.) plants were subjected to two different salinity levels (0 and 50 mmol L-1 NaCl) with and without the application of Si (0 and 2 mmol L-1 K2 SiO3 ) in order to evaluate its possible positive impact on mitigation of salinity stress-induced symptoms. An additional experiment was implemented with postharvest Si application (sodium silicate) to investigate effects on the shelf-life of tomato fruit. Salinity (50 mmol L-1 NaCl) decreased plant size, total yield and fresh fruit weight while a high percentage of blossom end rot symptoms of tomato fruit was also observed. The application of Si in the nutrient solution counteracted these detrimental effects, generating a higher yield and healthier fruit (lower blossom end rot incidence) compared to the untreated plants (no application of Si). Salinity improved several quality-related traits in tomato fruit, resulting in higher marketability, whereas the addition of Si (pre- and postharvest) maintained fruit firmness following storage thereby increasing the shelf-life of tomato fruit. These findings indicate that Si application (pre- and postharvest) could provide an effective means of alleviating the unfavorable effects of using low-quality water in plant fertigation on tomato plant development, fruit yield and post-harvest quality, through increased fruit firmness. © 2019 Society of Chemical Industry.

Alpha-tocopherol fertigation confers growth physio-biochemical and qualitative yield enhancement in field grown water deficit wheat (Triticum aestivum L.)

Water stress is a major problem to fulfill the world food demand and to solve the problem of malnutrition. Different strategies are being used to solve these problems including the fertigation of plants with different biochemical at different growth stages. The present study was conducted for the induction of drought tolerance in field grown wheat for better yield and nutritional quality through foliar spray of α-tocopherol (α-Toc) at start of reproductive stage. Water stress was maintained based on number of irrigation. Three levels of α-Toc 0.001, 0.01 and 0.1 mM were applied as foliar spray. Water stress significantly reduced the biomass production that associated with the decreased photosynthetic pigments, water relation, photosynthetic efficiency, but increased the lipid peroxidation, leaf relative membrane permeability, activities of antioxidant enzymes and the contents of phenolic, flavonoids, α-toc and ASA. Water stress also negatively effected the different yield attributes and seed nutrient quality. Foliar fertigation of wheat plants with α-Toc significantly improved the water stress tolerance of wheat plants in term of improvement in growth and seed yield associated with improved water relations, photosynthetic efficiency, contents of photosynthetic pigments and improvement in antioxidative defence mechanism (enzymatic and non-enzymatic antioxidants). Fertigation of water stressed wheat plants with α-Toc also improved the seed nutritional quality in terms of the contents of seed phenolics, flavonoids, activities of antioxidant enzymes and the content of α-, β- and γ-tocopherols. In conclusion, it was found that fertigation of water stressed wheat plants not only improved the water stress tolerance but also improved the seed yield and nutritional quality that will not only be helpful for the improvement in wheat yield that also be a step to solve the problem of malnutrition through the bio-fertification of α-Toc.

Improvement of yield and quality of two Spinacia oleracea L. varieties by using different fertilizing approaches.

The effects of different fertilizers [the control with no fertilizer (C), inorganic fertilization (I), combined inorganic and organic fertilizer (IOHumax1) and (IOHumax2)] on yield and nutrients contents of two spinach varieties ("Balady and Virofly") were investigated. Significant effects of variety were observed on vegetative growth and nutrients contents. While Virofly had significantly higher leaf area (236.96cm2), stem diameter (7.43mm)andfresh weight of vegetative and radical parts (15.05 and 0.96g, respectively), Balady had significantly higher chlorophyll and carotene contents (0.0023 and 0.0018g/g fw, respectively). No significant impacts of variety on vitamin C, nitrite, nitrate and oxalates contents were observed. IOHumax2 treatment (4g/l of Humax+100mg/l of NH4NO3 per plant fertigation-1) enhanced stem diameter and root growth andsignificantlyimproved the yield by produced plants with higher stem length, leaf number and surface area. This treatment improved the quality of plant by increasing vitamin C content and reducing nitrite and oxalates contents. No significant effects of different fertilizers were observed on NO3- content. A fairly balanced yield/NO3- and oxalates content can be achieved with combined inorganic and organic fertilizer (IOHumax1) and (IOHumax2).

The role of exogenous humic and fulvic acids in iodine biofortification in spinach (Spinacia oleracea L.)

The strong sorption of iodine in soils is a major factor that limits its uptake by plants. The aim of this study was to evaluate the influence of Humistar (a concentrate of exogenous humic acids 12 % w/w and fulvic acids 3 % w/w; abbreviated: HU) applied with KI or KIO3 on the efficiency of iodine biofortification, yield and the accumulation of undesirable compounds in spinach. Methods of iodine application with or without HU were tested in two pot experiments and a hydroponic study with spinach cultivation. The spinach biomass and the content of iodine, soluble oxalates, Cd and Pb in leaves were determined. The physicochemical properties and chemical composition of the soil and media were analysed. No negative influence of iodine and HU on spinach yield was observed. Fertigation with iodine resulted in a higher efficiency of iodine biofortification than its application pre-sowing (particularly for KIO3), with no increase in the Cd and Pb content in spinach plants compared to the control. The improvement of iodine uptake and root-to-leaf transfer (represented by higher transfer factor values) in spinach can be obtained by the application of HU via plant fertigation with IO3 −. The level of soluble oxalates in spinach grown in the pot experiments was not affected.

Valorization aboveground of the extract of compost ovine for fertigation of the vegetables plants in Tunisia

The main objective of this study was to highlight the fertilizing capacity of the extract of ovine compost (prepared to the simple infusion) in gardening nursery, while specifying the appropriate ratios of extraction and dilution ,for soilless plant fertigation intended for two strategic summer crops in Tunisia: seasonal tomato and seasonal pepper. It is clear that such extraction ratio of 1: 5 is effective for plants fertigation of two considered species. In addition, it has been shown that 200 times dilution of the concentrated extract is beneficial for the growth of tomato plants. However, this organic liquid fertilizer with different dilutions applied and in the experimental conditions adopted, wasn’t moderately efficient in stimulating the growth of pepper plants. The importance of this type of compost produced from sheep biomass, widely available in Tunisia, encourage the diversification of its exploitation, which is the object of this preliminary work, deserving more future investigations. Keywords: Compost, Compost Extract, Extraction, Dilution, Fertigation, Height Growth, Tomato and Pepper Plants

The response of hydroponically grown lettuce under Mn stress to differentiated application of silica sol

A way to alleviate excessive Mn nutrition of plants is through silicon application. The aim of the present study was to examine the effect of different Si concentrations in a nutrient solution and Si plant spraying treatments (in the form of silica sol) on the yielding and nutritional status of hydroponically grown lettuce under Mn-stress. The experiments were conducted under controlled conditions in a phytotron. The influence of the following Si levels in the nutrient solution (5.5 – control; 15.5; 23.25 and 31 mg Si dm-3) and foliar sprays (distilled water; Si solution) were investigated. Silicon supplied through fertigation significantly affected the plant’s nutrient status and alleviated the Mn stress, increasing fresh matter production, RWC (Relative Water Content) and the number of leaves per plants, while decreasing the share of dry matter. The Si nutrition did not change the content of Mn in the leaves, but caused a significant increase in N, P, Na, Fe and Si concentrations with a simultaneous decrease of Zn and Cu levels. The content of Ca, Mg and K was relatively stable (except for the treatment with the most intensive Si nutrition). Generally, the concentrations of N, P, K, Ca, Mg, Na and Fe within the tested Si range were higher than in the control, while being lower in the case of Zn and Cu. Overall, the foliar application of Si did not change plant yielding, the number of leaves on plants and most macro- and microelement concentration in leaves, but modified significantly the RWC as well as the Cu and Na content. The dry matter content under Si nutrition was varied. In summary, an effective method to alleviate Mn-stress is to apply silica sol to a nutrient solution used for plant fertigation.

Raw and fungal-treated olive-mill wastewater effects on selected parameters of lettuce (Lactuca sativa L.) growth – The role of proline

Olive-mill wastewater (OMW) constitutes a major agricultural waste stream for which disposal is associated with significant environmental repercussions. No data are available on the effects of biotreated OMW and of the protective role of exogenously provided proline on plant physiology. In the present study, OMW was administered, either raw or previously treated by the white-rot fungus Pleurotus ostreatus, with or without proline amendment, to lettuce plants growing in sterilized sand. Biotreated OMW and proline addition resulted in significant moderation of OMW adverse effects on plant biomass production and ascorbic acid content, while their synergistic action alleviated the severe negative impact on net photosynthetic rate, water use efficiency and photosynthetic activity (Fv/Fo) invoked by the effluent. Moreover, biotreated OMW supplemented with proline, moderated the decrease in chlorophylls exerted by raw OMW, but it did not contribute at restoring carotenoids content. Restoration of plant transpiration was complete when biotreated OMW was used (with or without proline); proline alone mitigated the negative impact of OMW on photosynthetic efficiency (Fv/Fm and Fv′/Fm′). It seems that key photosynthetic parameters could be exploited as suitable evaluators of wastewater-induced plant toxicity, while plant fertigation with biotreated and/or supplemented OMW could be an interesting prospect in valorizing this effluent.

Influence of iodine form and application method on the effectiveness of iodine biofortification, nitrogen metabolism as well as the content of mineral nutrients and heavy metals in spinach plants (Spinacia oleracea L.)

Biofortification of vegetables with iodine can become an alternative (in reference to salt iodization) method of introducing this element to human diet. Side-effects of iodine application on mineral nutrition of plants have not yet been thoroughly documented. The aim of the study was to evaluate the effect of iodine form and the method of I fertilization on iodine biofortification, nitrogen metabolism and the level on mineral nutrients and selected heavy metals in spinach plants. In the present research, pot cultivation of spinach ‘Olbrzym zimowy’ cv. was carried out on heavy soil including the following treatments: 1 – control (without iodine application), 2 – pre-sowing KI fertilization, 3 – pre-sowing KIO3 fertilization, 4 – fertigation with KI, 5 – fertigation with KIO3. In treatments no. 2 and 3 iodine was applied in a dose of 1mgIper1dm3 of soil. In treatments no. 4 and 5, water solution of iodine in the concentration of 0.0004% was used – approximately 1.1mgIdm−3 of soil was introduced during the cultivation. Introduction of iodine by fertigation proved to be much more effective for iodine biofortification of spinach than pre-sowing fertilization with this element – by 339% and 498% respectively for KI and KIO3. Pre-sowing soil fertilization with KI and KIO3 improved accumulation of nitrates(V) and chlorides in spinach. Soil application of iodine (in the form of KI and KIO3 – combination no. 2 and 3) increased N-total content in spinach plants. Fertigation of plants with KI and KIO3 significantly reduced the level of ammonium ions in spinach. Lowered content of Ca as well as higher accumulation of Fe were found in plants from treatments no. 2, 4 and 5. Application of iodine (irrespective of its chemical form and method) in spinach cultivation (treatments 2–5) decreased Na and Zn content in plants. Pre-sowing fertilization with KI and KIO3 reduced Pb accumulation in spinach. No influence of iodine fertilization and fertigation was found in reference to yield as well as the content of P, K, Mg, S, B, Cu, Mn, Mo and Cd in spinach plants.