Non-fertilized Plants Research Articles

Impact of Fertilization on Productivity and Nutritional Quality of Napier Varieties in Southern Mindanao, Philippines

Aims: This study investigates the effects of fertilizer application on the growth performance, proximate composition, and chlorophyll content of three Napier grass varieties (King, Pakchong, and Juncao) in Southern Mindanao, Philippines. Study Design: Utilizing a Randomized Complete Block Design with a 3x2 factorial arrangement. Place and Duration of Study: The experiment was performed at the University of Southern Mindanao Animal Production Center facilities from January to March 2023. Methodology: The three Napier grass varieties (King, Pakchong, and Juncao) was the first factor, and fertilizer application (with or without) were the second factor. Four blocks were prepared, each containing six plots, resulting in 24 plots. The fertilized plots received two applications of 150kg N/ha and 75kg N/ha of the recommended NPK fertilizer, respectively, while non-fertilized plots did not receive any fertilizer. Results: Results showed that fertilizer application significantly improved herbage yield, with fertilized plants yielding 20.25 tons per hectare compared to 15.14 tons in non-fertilized plants. Pakchong exhibited the highest yield and crude fiber content, while Juncao grass showed higher crude protein content without fertilizer. Fertilization also increased ether extract content, with Pakchong displaying the greatest response. However, nitrogen-free extract (NFE) was higher in non-fertilized plants across all varieties, indicating a complex interaction between nutrient availability and carbohydrate allocation. Conclusion: These findings underscore the importance of targeted fertilizer management to optimize both growth and nutritional quality, depending on specific production goals. The differential responses among Napier varieties suggest the potential for variety-specific fertilization strategies, which can enhance forage quality and sustainability in livestock farming. Further research is recommended to explore the long-term impacts of continuous fertilization and the underlying genetic mechanisms driving varietal differences.

Assessment of Semi-autotrophic Hydroponics on in vitro propagated Jamaican Sweet Yam (Dioscorea alata) - Analysis of Variance and Principal Component Analysis

Objective: Despite its benefits, plant tissue culture tends to incur a high production cost hence the need for cost-reduction strategies, especially with regards to acclimatization. One such strategy is to use semi-autotrophic hydroponics (SAH). SAH is a novel, low-cost technology that has been designed for the high-ratio and rapid propagation of clonal or vegetatively propagated crops. Sweet yam is a major export commodity of Jamaica and there is need to produce disease-free plants that require less pampering during hardening. The aim of this study is to analyze SAH in tissue culture of Jamaican sweet yams. Methods: Rooted sweet yam (Dioscorea alata) in vitro cultures were transferred to a commercial sphagnum peat moss based potting substrate, with vermiculite and fine calcitic and dolomitic limestone and the SAH system was run in a growth chamber at a tissue culture facility. Six tissue culture yam plantlets were incubated in polypropylene vessels and placed on separate shelves with north facing rows and south facing rows. Samples were treated with commercial fertilizer and controls were treated with tap water. Results: Fertilized plants showed significantly higher mean number of nodes (8.0±2.2 and 7.5±1.8) compared to non-fertilized plants (4.0±0.9 and 5.0±2.1) and significantly higher maximum leaf area index (41.42±15.49cm2 and 35.58±16.93cm2) versus non-fertilized plants (19.17±6.42cm2 and 23.58±6.55cm2). Fertilizer significantly reduced the mean number of mini tubers per plant (0.67±0.52). Non-fertilized (control) produced 2.50±1.05 and 1.83±0.41 mini tubers per plant. The mean mini tuber yields per plant were significantly reduced from 1.05±0.26g and 1.00±0.83g in non-fertilized (controls) to 0.28±0.30g and 0.34±0.40g in fertilized treatments. Principal Component Analysis (PCA) revealed three principal components accounting for 81.47% of the observed variance. PC1, 2 and 3 accounted for 39.28%, 30.49% and 11.64% of the variance respectively. PC1 described factors responsible for the vegetative growth, PC2 factors for mini tuberization and PC3 effects due to positioning of plants on shelves. Conclusion: SAH is a very flexible and adaptable technique which was found to be very useful in the acclimatization of tissue culture for Jamaican sweet yam plants. Commercial fertilizer application was found to be an efficient means of nutrient addition to promote vegetative growth. Fertilizer application significantly increased the number of nodes and maximum leaf area while it significantly reduced tuber quantity and yield. The ANOVA and PCA showed that fertilizer application was positively correlated to vegetative production factors while it was negatively correlated to mini tuber yield.

Growth, Yield and Economic Advantage of Onion (Allium cepa L.) Varieties in Response to NPSB Fertilizer and Planting Pattern

Haphazard and low soil fertility, low yielding verities and poor agronomic practices are among the major factors constraining onion production in the central rift valley of Ethiopia. Therefore, a field experiment was conducted in East Showa Zone of Adami Tulu Jido Combolcha district in central rift valley areas at ziway from October 2021 to April 2022 to identify appropriate rate of NPSB fertilizer and planting pattern of onion varieties. The experiment was laid out in split plot design of factorial arrangement in three replications. The main effect of NPSB blended fertilizer rates and varieties (red coach and red king) significantly (p<0.01) influenced plant height, leaf length, leaf diameter, leaf number and fresh leaf weight, shoot dry matter per plant, and harvest index. Total dry biomass, bulb diameter, neck diameter, average fresh bulb weight, bulb dry matter, marketable bulb yield, and total bulb yield were significantly (p<0.01) influenced only by the main effect of NPSB blended fertilizer rates. In addition, unmarketable bulb yield was statistically significantly affected (p≥0.05) by the blended fertilizer rates and planting pattern. Moreover, days to 90% maturity of onion was affected by the main factor of NPSB fertilizer rate, variety and planting pattern. The non-fertilized plants in the control treatment were inferior in all parameters except unmarketable bulb yield and harvest index. Significantly higher marketable bulb yield (41 t ha-1) and total bulb yield (41.33 t ha-1) was recorded from 300 kg ha-1 NPSB blended fertilizer rate applied. Double row planting method and hybrid red coach onion variety had also gave higher growth and yields. The study revealed that the highest net benefit of Birr, 878,894 with lest cost of Birr 148,006 by the combinations of 150 kg blended NPSB ha-1 with double row planting method (40cm*20cm*7cm) and red coach variety which can be recommendable for higher marketable bulb yield and economic return of hybrid onion for small scale farmers in the study area. Also, for resource full producers (investors), highest net benefit of Birr 1,205,372 with higher cost (159,628 Birr) by application of 300 kg NPSB ha-1 is recommended as a second option. However, the research should be replicated both in season and areas to more verify the recommendations.

The Effect of Organic Fertilization and Jasmonic Acid on the Morphological, Quantitative, and Chemical Parameters of Okra (Abelmoschus esculentus L.) variety Hussainawiya

A study was conducted in a field belonging to the Najaf Agriculture Directorate/Najaf/Iraq during the spring growing season of 2021. The study aimed to analyze the response of okra variety Hussainiya for two factors. The first studied factor was three levels of DPW (decomposed palm waste), including 0, 16, and 32 tonha-1, while the second factor was three levels of a foliar application of Jasmonic acid, including 0, 15, and 30 mgL-1. Randomized Complete Block Design (RCBD) was used to model the factorial experiment with three replications, and the Least Significant Differences (LSD) were selected to compare the means at the probability level of 0.05. The results showed the significant superiority of organic fertilization treatment of DPW at the level of 32-ton ha-1 compared with control treatments in the studied parameters, recording the highest value of the plant height, total number of leaves, total leaf area, dry weight of the vegetative system, number of fruits per plant, the yield of one plant, total yield, the percentage of nitrogen in leaves, the total chlorophyll percentage, and the total soluble carbohydrates in fruits. The foliar application of 30 mg. L-1 Jasmonic acid gave significantly higher values for the above indicators than control treatments. The interaction between the application of 32 tons. ha-1 DPW and 30 mg L-1 Jasmonic acids showed significant superiority over other treatments in all studied indicators. These indicators were plant height 131.66 cm, total number of leaves 42.55 leaves plant-1, total leaf area 1.66 m2plant-1, dry weight of the vegetative system 95.48 g plant-1, fruits number 77.15 fruit plant-1, yield of one plant 884.75 g plant-1, total yield 56.17 tons. ha-1, nitrogen in leaves 2.262%, total chlorophyll in leaves 80.91 mg.100 g-1FW, and carbohydrates in fruits 20.33%. While the interaction between non-fertilized plants sprayed with water only recorded significantly the lowest value of these indicators, which scored 77.10 cm, 20.36 leaf plant-1, 0.59 m2plant-1, 54.11 g plant-1, 47.23 fruit plant-1, 237.42 g plant-1, 15.07-ton ha-1, 1.351%, 47.45 mg.100 g-1 fresh weight, and 6.77% respectively. Keywords: Abelmoschus plant; decomposed palm waste; Jasmonic acid; okra, Organic fertilizer; yield indicators.

Phyllosphere Exudates Select for Distinct Microbiome Members in Sorghum Epicuticular Wax and Aerial Root Mucilage

Phyllosphere exudates create specialized microhabitats that shape microbial community diversity. We explored the microbiome associated with two sorghum phyllosphere exudates, the epicuticular wax and aerial root mucilage. We assessed the microbiome associated with the wax from sorghum plants over two growth stages, and the root mucilage additionally from nitrogen-fertilized and nonfertilized plants. In parallel, we isolated and characterized hundreds of bacteria from wax and mucilage, and integrated data from cultivation-independent and cultivation-dependent approaches to gain insights into exudate diversity and bacterial phenotypes. We found that Sphingomonadaceae and Rhizobiaceae families were the major taxa in the wax regardless of water availability and plant developmental stage to plants. The cultivation-independent mucilage-associated bacterial microbiome contained the families Erwiniaceae, Flavobacteriaceae, Rhizobiaceae, Pseudomonadaceae, and Sphingomonadaceae, and its structure was strongly influenced by sorghum development but only modestly influenced by fertilization. In contrast, the fungal community structure of mucilage was strongly affected by the year of sampling but not by fertilization or plant developmental stage, suggesting a decoupling of fungal–bacterial dynamics in the mucilage. Our bacterial isolate collection from wax and mucilage had several isolates that matched 100% to detected amplicon sequence variants, and were enriched on media that selected for phenotypes that included phosphate solubilization, putative diazotrophy, resistance to desiccation, capability to grow on methanol as a carbon source, and ability to grow in the presence of linalool and β-caryophyllene (terpenes in sorghum wax). This work expands our understanding of the microbiome of phyllosphere exudates and supports our long-term goal to translate microbiome research to support sorghum cultivation.

Variations on primary metabolites of the carrageenan-producing red algae Sarcopeltis skottsbergii from Chile and Sarcopeltis antarctica from Antarctic Peninsula

Several studies reported that gametophytes and tetrasporophytes of Gigartinaceae produce different carrageenan types, as observed in Sarcopeltis species although they have isomorphic haploid and diploid phases. Cystocarpic and non-fertile plants of Sarcopeltis (ex Gigartina) skottsbergii produced kappa-carrageenans, while tetrasporophytes produced lambda-carrageenans, and yields were higher in cystocarpic and sterile specimens than in tetrasporophytes. However, comparison on the other primary metabolites among different life history phases still needed to be investigated. Then, we tested the hypothesis if the variation on primary metabolites (pigments, proteins and carbohydrates) are related to the life history phases of Sarcopeltis antarctica and Sarcopeltis skottsbergii, and/or are influenced by abiotic factors. Primary metabolites of S. antarctica varied according to the life-history phases: non-fertile specimens presented higher phycobiliprotein concentrations, tetrasporophytes presented higher chlorophyll a concentrations, and cystocarpic specimens presented higher concentrations of proteins, polysaccharides and floridean starch. However, primary metabolites of S. skottsbergii varied in response to some abiotic factors (nutrients, temperature and salinity), since principal component analysis evidenced two groups; one was related by the higher nitrate and phosphate concentrations, and the other was related to the higher temperatures and lower salinities. Concentrations of floridean starch, low molecular weight carbohydrates, and polysaccharides are higher in S. antarctica than in S. skottsbergii, which could be related to the protective role of these compounds against salinity variation and low temperatures faced in the Antarctic extreme environments.

Phosphorous fertilization alleviates shading stress by regulating leaf photosynthesis and the antioxidant system in mung bean (Vigna radiata L.)

Shading can limit photosynthesis and plant growth. Understanding how phosphorus (P) application mitigates the effects of shading stress on morphology and physiology of mung beans (Vigna radiata L.) is of great significance for the establishment of efficient planting structures and optimizing P-use management. The effects of various light environments (non-shading stress, S0; low light stress, S1; severe shading stress, S2) on the growth of two mung bean cultivars (Xilv1 and Yulv1) and the role of P application (0 kg ha−1, P0; 90 kg ha−1, P1; 150 kg ha−1, P2) in such responses were investigated in a field experiment. Our results demonstrated that shading decreased the dry matter accumulation of mung bean markedly by limiting photosynthesis capacity and disrupting agronomic traits. For the leaf areas of the two cultivars, chlorophyll a+b, the net photosynthetic and electron transport rates were increased by 16.8%, 20.0%, 15.5%, and 12.5% under P1 treatment, and by 32.4%, 40.3%, 16.3% and 12.8% under P2 treatment, respectively, when compared to those for the non-fertilized plants under shading stress. These responses resulted in increased light capture and weak light utilization. Moreover, the activities of superoxide dismutase and peroxidase were enhanced by 20.9% and 43.7%, respectively; malondialdehyde and superoxide anion contents were reduced by 18.6% and 14.1%, respectively, under P application. These findings suggest that P application moderately mitigates the damage caused by shading stress and enhances tolerance by regulating mung bean growth. In addition, Xilv1 was more sensitive to P under shading stress than Yulv1.

GROWTH PARAMETERS OF BLUEBERRY (<i>Vaccinium</i> spp.) PLANTS INOCULATED WITH <i>Pseudomonas fluorescens</i>

The production and consumption of blueberry have increased in Mexico owing to its health benefits. Symbiotic relationships have been shown to be crucial in blueberry plants. In particular, phytohormone production by Pseudomonas fluorescens is an important mechanism of plant growth promotion. However, there are only a few reports on the effects of plant growth-promoting bacteria in blueberries. Therefore, we aimed to evaluate the effects of four strains of P. fluorescens (UM16, UM240, UM256, and UM270) and two types of slow-release fertilizer (nitrophosphate and basacote) on the development of blueberry var. Biloxi under greenhouse conditions. Blueberry seedlings obtained from in vitro culture and adapted under greenhouse conditions were inoculated with 1 x 106 CFU with any of the four strains, depending on treatment. Plants inoculated showed increased average plant length, plant fresh weight, root length, and root fresh and dry weight, compared with those with the control treatment (non-inoculated plants). The plants inoculated and fertilized with nitrophosphate had a better development compared with those fertilized with basacote or the control plants (inoculated or fertilized). Inoculated plants fertilized with nitrophosphate also had greater plant length, higher fresh plant weight, longer roots, and greater root fresh and dry weight than the control (non-inoculated or non-fertilized plants). Our study could facilitate the sustainable propagation of blueberry plants.

Long-Term Maternal Fertilizer Addition Increased Seed Size but Decreased Germination Capacity and Offspring Performance in Taxus baccata L.

Plant fitness and species persistence depend on seed quantity and their ability to germinate and produce viable offspring. Although maternal environment can have a great impact on seed quality, few studies are pointing to the transgenerational effect of maternal environment on germination rate and offspring traits. Moreover, global changes connected to nitrogen and phosphorus deposition can also impact plants’ reproductive performance. Here, we collected Taxus baccata L. seeds produced by the same genotype female plants grown in different nutritional regimes. We use them to analyze seed size and the impact of long-term fertilization on germination capacity and offspring traits. Our results show that long-term maternal fertilizer addition increases the ratio of large seeds produced, but at the same time decreases germination capacity compared to control and nonfertilized plants. Moreover, it was demonstrated that maternal environment impacts seed traits and germination rate, and seed mass rather than maternal environment impacts offspring performance. Therefore, the study provides information on how the maternal environment regulates seed traits and germination capacity as well as seedling growth to adapt to increased nitrogen and phosphorus deposition and improves prediction about plants’ response to global environmental changes.

Nursery fertilization affected field performance and nutrient resorption of Populus tomentosa Carr. ploidy levels

Nutrient resorption (NuR) is an important nutrient conservative strategy but little information is available about the effect of nursery fertilization on NuR in the field. In this study, diploid and triploid one-year-old plants of Populus tomentosa Carr. were fertilized with 9 g N per plant, and non-fertilized plants as control. Initial functional attributes, i.e., height, diameter, stem mass, mineral nutrients and non-structural carbohydrate (NSC) levels of each tissue, were measured before planting. Field performance (survival, total height, diameter, stem volume and their growth, leaf nutrient status, and NuR) were measured in the field. Compared to control, 9 g N per plant was benefit for plant growth, mineral nutrients and NSC accumulation of diploids, but declined plant size of triploids before planting. While in the field, fertilization effect on plant size was inversed for each ploidy level. Nursery fertilization increased nitrogen resorption efficiency (NRE) of triploids and decreased phosphorus resorption efficiency (PRE) of both ploidy levels. Initial plant size were the most effective parameters predicting field performance and NuR. Furthermore, NRE was multi-elements controlled as indicated by the correlation of N and P in green and senesced leaves, while PRE was only positively correlated with P in green leaves. However, there was no relationship between field growth and NuR. This study deepened our understanding of NuR from the perspective of artificial managements, for instance nursery fertilization.

Nitrogen Supply Affects Grain Yield by Regulating Antioxidant Enzyme Activity and Photosynthetic Capacity of Maize Plant in the Loess Plateau

Nitrogen (N) is the most limiting nutrient for maize, and appropriate N fertilization can promote maize growth and yield. The effect of N fertilizer rates and timings on morphology, antioxidant enzymes, and grain yield of maize (Zea mays L.) in the Loess Plateau of China was evaluated. The four N levels, i.e., 0 (N0), 100 (N1), 200 (N2), and 300 (N3) kg ha−1, were applied at two timings (T1, one-third N at sowing and two-thirds at the six-leaf stage of maize; T2, one-third applied at sowing, six-leaf stage, and eleven-leaf stage of maize). The results show that N2 and N3 significantly increased the plant height, stem and leaf dry weight, and leaf area index of maize compared with a non-N-fertilized control (N0). The net photosynthetic rate, transpiration rate, stomatal conductance, and leaf chlorophyll contents were lower, while the intercellular carbon dioxide concentration was higher for non-fertilized plants compared to fertilized plants. The activities of peroxidase (POD) and superoxide dismutase (SOD) increased with N rate, but the difference between 200 and 300 kg ha−1 was not significant; further, the isozyme bands of POD and SOD also changed with their activities. Compared with a non-N-fertilized control, N2 and N3 significantly increased grain yield by 2.76- and 3.11-fold in 2018, 2.74- and 2.80-fold in 2019, and 2.71- and 2.89-fold in 2020, and there was no significant difference between N2 and N3. N application timing only affected yield in 2018. In conclusion, 200 kg N ha−1 application increased yield through optimizing the antioxidant enzyme system, increasing photosynthetic capacity, and promoting dry matter accumulation. Further research is necessary to evaluate the response of more cultivars under more seasons to validate the results obtained.

Efekat inokulacije bradirizobijalnim i fosfosolubilizirajućim bakterijama na prinos i sastav semena soje

In the field experiment, the effect of co-inoculation with Bradyrhizobium japonicum and two Pseudomonas sp. strains on seed yield and macronutrient uptake in soybean (Glycine max L.) was evaluated. The results showed that inoculation and co-inoculation of soybean seeds with B. japonicum and Pseudomonas sp. strains increased seed yield (from 65 up to 134%), and uptake of N, P, K, Mg, and Ca (kg ha-1 ) (from 65 to 167%), compared to the control plants (uninoculated, non-fertilized plants). Phosphorous concentration (mg kg-1 ) was increased in inoculated and co-inoculated treatments (up to 15%), compared to the control. The N%, as well as the concentrations of K and Ca, did not differ significantly among treatments and control. Magnesium concentrations were increased in mineral fertilized and co-inoculated treatments. Uptake of all nutrients was in significant correlation with seed yield, while the concentration of P only correlated with seed yield. The results showed that coinoculation with bradyrhizobial and some phosphate solubilizing bacteria can increase the seed yield and uptake of N and P in soybean.

Adjusting P-K Fertilization and Liming Strategies to Enhance Yield of Cherry Tomato Plants Grown on an Oxisol

ABSTRACT Although cherry-tomato is becoming more popular in the last years, there are no specific recommendations for P and K fertilization or liming strategies for this specific variety. Our aim was to assess rates of P and K and liming strategies in order to improve the yield of cherry-tomato grown on an Oxisol with a limited P-availability. Two pot experiments were developed. In the first-one, a two-factor factorial design was developed with 4 P (first-factor) and 4 K rates (second-factor), being these rates the 0%, 50%, 100%, and 200% of the recommended fertilization for tomato in South-Brazil. In the second experiment, the soil pH (4.3) was adjusted to 5.5, 6.0, and 6.5 with limestone. Soil P-availability, plant growth, diameter, number of fruits and cherry tomato yields were increased with the P addition, while a non-significant effect was observed after adding K. The highest yield was produced with 50% of the suggested amount of P for tomato in comparison with the non-fertilized plants (yield increase of 674%), while higher P rates (100% and 200%) produced a lower yield increase. The significant effect of soil liming was observed on increase of the flower bunches number when the soil pH was amended to 6.5. Cherry-tomato requirements seem to be different from the recommended for other varieties. Our results indicate that higher yields were achieved with a lower amount of chemical inputs than the recommended for tomato in general, stressing the importance of P for tomato cherry production over the other factors assessed here.

Pathogenic and Non-Pathogenic Fungal Communities in Wheat Grain as Influenced by Recycled Phosphorus Fertilizers: A Case Study

Waste-based fertilizers provide an alternative to fertilizers made from non-renewable phosphate rock. Fungal communities colonizing the grain of spring wheat fertilized with preparation from sewage sludge ash and dried animal blood (Rec) and the same fertilizer activated by Bacillus megaterium (Bio) were evaluated against those resulting from superphosphate (SP) and no phosphorus (control, C0) treatments. The Illumina MiSeq sequencing system helped to group fungal communities into three clades. Clade 1 (communities from C0, Bio 60 and 80, Rec 80 and SP 40 kg P2O5 ha−1 treatments) was characterized by a high prevalence of Alternaria infectoria, Monographella nivalis and Gibberella tricincta pathogens. Clade 2 (Bio 40 kg, Rec 40 and 60 kg, and SP 60 kg P2O5 ha−1) was characterized by the lowest amount of the identified pathogens. Commercial SP applied at 80 kg P2O5 ha−1 (clade 3) induced the most pronounced changes in the fungal taxa colonizing wheat grain relative to non-fertilized plants. The above was attributed mainly to the lower amount of A. infectoria and higher counts of species of the family Nectriaceae, mostly epiphytic pathogens Fusarium culmorum and Fusarium poae.

Effect of Nitrogen Fertilizer on Growth, Flowering, Fruiting and Nodulation of Three Varieties of Common Bean in the Arid Region of Aïn Naga (Biskra, Algeria)

Field experiments were conducted to investigate the response of common bean (Phaseolus vulgaris L.) to nitrogen fertilizer. The main factor included the fertilizer (Granular Urea 46% N), was made up of two levels: no fertilization (0 kg/plot: control) and fertilization (0.4 kg/plot), while the secondary factor was the variety (three varieties of common bean: Djedida, Nelson and Jalila). The experimental design was a randomized complete block design with split plot arrangement and replicated four times. The effect of fertilization was evaluated during two development stages (flowering and fruiting) for each variety and this on the total dry biomass, the length of the aerial and root parts, as well as on the number of secondary roots. On the other hand, the combined effect of fertilization and variety was studied on some yield parameters per plant, such as the number of flowers, pods, seeds and the harvest index. In addition, the number of nodules at the end of seed maturation was evaluated. The results indicated that the nitrogen fertilizer application significantly reduced the root length, the number of nodules and secondary roots in most of the common bean varieties. However, fertilizer application significantly increased dry matter in both flowering and fruiting stages, for the three studied varieties. Pod number per plant and seed yield was increased by the application of N fertilizer, depending on varieties and the parameters being measured. Djedida and Jalila varieties gave the best yield and can therefore be recommended to farmers. According to our results, the percentage of improvement by N fertilization on one parameter or another does not exceed an average of 20%, compared to the control. Indeed, the effect of fertilization is positive and seems to increase the harvest index by 18% in Djedida and by 20% in Jalila, compared to non-fertilized plants. Unfertilized plants of the variety Nelson showed the highest ability to nodulate.

Yield, content and nutrient uptake by winter wheat and spring barley in response to applications of digestate, cattle slurry and NPK mineral fertilizers

ABSTRACT Digestate represents an alternative source of nutrients for crops in sustainable agriculture. We aimed to evaluate the effects of digestate fertilization on grain (GY) and straw yield (SY) and nutrient content and uptake in winter wheat (WW) and spring barley (SB). The study duration was from 2012 to 2016, with the following crop rotation: WW/WW/SB/WW. Every year, the same fertilizers were applied to each respective plot: control, digestate, digestate + straw, cattle slurry and mineral NPK fertilizer. Significantly higher GY and SY were noted after fertilizer application each year compared to the non-fertilized control. The average effect of the fertilizers on GY of WW was control < NPK ≤ digestate + straw ≤ cattle slurry ≤ digestate. Fertilizer application also increased N, S, Na, Zn and Fe content in the grains, especially when digestate was used as fertilizer. However, in non-fertilized plants (control), only the K content increased in the grains, although the uptake of K is positively correlated with GY. Our results show that digestate can be used not only as a replacement for cattle slurry but also as an alternative fertilizer, which, under certain soil conditions, is more effective than NPK fertilizer.

Effect of some Agricultural Treatments on Chemical and Qualitative Characters of Five Cucumber hybrids Grown under Unheated Greenhouse

The experiment was implemented in greenhouse at College of Agriculture and Forestry, University of Mosul, During the spring growing season of 2014 to study the evaluation of genetic behavior of some traits in five cucumber hybrids (Raiane, Karol, Sayff, Karima and Baraka) under the effect of fertilization with two plant extracts treatments (control and fertilization with humic acid at concentrate 6 gm.-l) and harvesting fruits in two periods in each (two days or three days) on growth and yield of cucumber. The experiment results subjected to statistical analysis arranged in R.C.B.D. with three replications. The results can be summarized as follows, Leaves content of nutrient elements, The Baraka hybrid exhibited non-significant in N % of leaves superiority, and the hybrid Raiane in P% of leaves and the hybrid Karima in K% of leaves as compared with other hybrids. Plants fertilized with humic acid were surpassed significantly over the non-fertilized plants in N % of leaves only, The results revealed non-significance in nutrient elements percentages between the fertilized and non-fertilized plants. Treatments of triple interactions showed a significant increase in traits of N % and P % of leaves. Yield qualitative trait, The differences did not reached a significant effect between the fertilized and non-fertilized plants, The plants harvested in each of two and three days revealed non-significant differences in all traits except in trait GA3 of leaves, where the plants of two-days harvesting were superior significantly on the plants of three days harvesting.

Foliar fertilization of two dominant species in a semiarid ecosystem improves their ecophysiological status and the use efficiency of a water pulse

The role of soil fertility in modulating plant water utilization from rainfall pulses under dryland conditions is poorly understood. Moreover, the effectiveness of soil fertilization in drylands is difficult to ensure due to immobilization of nutrients such as phosphorus and micronutrients. The use of foliar fertilization could overcome these difficulties, but its effectiveness has not been evaluated in wild dryland plants so far. In this study, we assessed the responses to foliar P, Fe, Mn and Zn fertilization before a rainfall event in two Mediterranean species with contrasting strategies to cope with drought/light stress, namely, Stipa tenacissima (poikilochlorophyllous) and Rosmarinus officinalis (photoprotective). We hypothesized that foliar fertilization can mitigate soil nutritional constraints and trigger physiological improvements enabling a more efficient use of water pulses. In non-fertilized plants, the rainfall event triggered increases in chlorophyll content, epoxidation of xanthophyll cycle pigments and PSII efficiency, indicating stress alleviation and photosynthesis improvement, but also induced decreases in foliar concentrations of several elements. Foliar fertilization increased the concentrations of sprayed nutrients in the leaves of both species. In R. officinalis, P and Zn fertilization also increased carotenoid concentrations, PSII photochemical efficiency and photosynthesis rates, and changed δ18O isotope ratios. While in S. tenacissima, Fe and Mn fertilization increased photosynthetic pigment concentrations without affecting PSII efficiency. The results obtained show that foliar fertilization can mitigate soil nutritional constraints affecting dryland vegetation, thereby promoting species-specific physiological responses to cope with water and/or light stress and ultimately leading to a more efficient use of rainfall pulses.

Plonowanie jęczmienia jarego w warunkach nawożenia siarką

In the last 20 years, due to a significant reduction in industrial emissions and changes in the assortment of available fertilizers, a progressive sulphur deficiency has been observed in the soils of Poland and other parts of the world. This creates the need to supplement NPK fertilizers with sulphur and to conduct research on the optimization of its use as a fertilizer component. A three-year field study was carried out on Haplic Luvisols with low content of sulphur available to plants. The aim of the study was to assess the effect of sulphur-containing fertilizers (ammonium sulphate, potassium sulphate and Wigor S) applied at rates of 20 and 40 kg S/ha on the yield of grain, straw and protein of spring barley. The study showed that application of sulphur, irrespective of its form, generally significantly increased the yield of spring barley grain and straw as compared to the control. However, no significant differences were found in the effects of the fertilizers on yield depending on either the fertilizer type or application rate. Protein content in the grain of the plants fertilized with sulphate sulphur was on average about 6% higher than in the grain of non-fertilized plants. As a result of the beneficial effect of sulphur on the yield of spring barley grain and on its protein content, the protein yield increased. The highest increases were obtained following application of sulphate fertilizers, especially at a 40 kg S/ha. The research suggests that irrespective of the form used, sulphur fertilization in the conditions of deficiency of this nutrient in the soil, with relatively high temperatures and high soil moisture, significantly affects the yield of spring barley grain and straw and the accumulation of protein in the grain.

GASEOUS CO2 EXCHANGE IN SILVER BIRCH SAPLINGS GROWING UNDER DIFFERENT LEVELS OF NITROGEN SUPPLY

A comparative assessment of gaseous CO 2 exchange in leaves of 5–6 years old saplings o f two forms of silver birch ( Betula pendula and Betula pendula var. сarelica ) and downy birch ( Betula pubescens Ehrh., 1789) growing under different levels of nitrogen nutrition was done. The study was carried out in five plots (control sector, three sectors fertilized with different doses of NH 4 NO 3 , and a sector with NPK fertilization) at the Agrobiological Research Station of the Karelian Research Centre RAS located at the southern outskirts of Petrozavodsk. Both in the control sector (where the content of nitrogen was 0.23 ± 0.04 %) and in most of the fertilized sectors, there was no significant difference between the mean values of photosynthesis in B. pendula and B. pendula var. сarelica either for the entire PhAR range or for PhAR > 1400 μmol m- 2 с -1 . Nitrogen fertilization had a beneficial effect on the growth and the magnitude of gaseous CO 2 exchange of the studied objects. The calculated parameters of light response curves for net photosynthesis have shown an improved performance of the photosynthetic apparatus upon fertilization. Where PhAR values were low, its efficiency in Karelian birch was much higher compared with silver birch ( B. pendula ), and increased with the elevation of the nitrogen dosage. In the conditions of soil moisture shortage, there was no significant difference between chlorophyll content in leaves of fertilized and non-fertilized plants. The carotenoid content in the leaves of non-fertilized plants was 1.3–1.5‑fold that of fertilized plants. Even a small dose of nitrogen fertilizer (20 g per tree) had a favorable effect on the water content of leaves in a dry period. In the second year of fertilization, the midday depression of photosynthesis increased considerably, especially in the sectors with high doses of nitrogen fertilizer. In the control sector, the decrease in photosynthesis in the absence of air drought and with sufficient soil moisture content was 20–25 %, and in fertilized plots there was a more than three-fold decrease in photosynthesis from 13:00 to 16:00. As a result, on sunny days in the second part of the growing season daily photosynthetic production in fertilized plants was lower compared to non-fertilized ones. In the first year of fertilization, there was no strong midday depression of photosynthesis, and nitrogen fertilization promoted CO 2 uptake on both cloudy and sunny days.