Search Results (30)

Phosphorus (P) is an essential macronutrient, but its limited availability in calcareous soils remains a major constraint to crop nutrition. Treated wastewater (TWW) offers a sustainable irrigation source in arid regions, enhancing water supply and contributing nutrients such as P. This study evaluates the effects of TWW and tap water (TW) irrigation, combined with varying rates of phosphorus fertilizers, such as single superphosphate (SSP) and diammonium phosphate (DAP), on maize (Zea mays L.) growth, nutrient uptake, and soil properties. A greenhouse experiment was conducted using maize grown in sandy calcareous soil. TWW irrigation with SSP (40 kg/ha) and DAP (20 kg/ha) resulted in the highest shoot dry matter (2.6 g), while TW with DAP at 20 kg/ha produced 2.2 g. Root biomass was generally higher, peaking at 8.3 g under TWW-SSP (40 kg/ha) and 5.7 g under TW-SSP (40 kg/ha). Nitrogen uptake was highest under TWW, with TWW-DAP (40 kg/ha) yielding the highest N content in shoots (1.9%) and roots (1.2%). Phosphorus content peaked at TWW-DAP (30 kg/ha) in shoots (0.52%) and roots (0.26%). Potassium uptake also improved with TWW, particularly in shoots (4.5%) under TWW-SSP (40 kg/ha) and roots (2.6%) under TWW-DAP (40 kg/ha). Post-harvest soil analysis showed TWW maintained stable EC (0.3–0.5 dS/m) and neutral pH (7.6–7.8). Higher DAP rates (40 kg/ha) with TWW increased soil organic matter, nitrogen (266.2 mg/kg), phosphorus (38.0 mg/kg), and potassium (385.3 mg/kg). In contrast, TW irrigation had lower nutrient enhancement, though high DAP rates still improved soil fertility. These findings highlight the potential of integrating TWW with phosphorus fertilizers to improve crop performance and soil fertility in calcareous soils. This approach offers a sustainable alternative to conventional practices, supporting sustainable crop production in water-limited environments. Further long-term studies are recommended to assess the sustainability of TWW irrigation in arid soils. Full article

The large-scale dieback of spruce monocultures, especially in the lower alpine, has become a significant problem and has necessitated the restoration of these areas, mainly using seedlings produced in forest nurseries. The primary source of nutrients for seedlings can be slow-release fertilizers and an appropriate dose of fertilizer improves the efficiency of its use and minimizes the negative environmental impact associated with the excessive use of mineral fertilizers. Aims: This study aimed to evaluate the effect of applying different fertilizer dose combinations on the accumulation of macronutrients in different parts of the seedlings (roots, shoots, and leaves) and on the morphology and development of fine roots. Methods: This research was carried out on producing beech seedlings with the application of starter soil fertilization with Yara Mila Complex (YMC) and Osmocote Exact Standard 3-4M (OES) fertilizers in four varying doses. Results: No deficiency of the analyzed macronutrients was noted in any of the tested fertilization variants. The highest content of all analyzed macronutrients was recorded in the leaves of beech seedlings, with values in roots and shoots being several times lower. The mixed fertilization variant OES 1.0 + YMC 1.0 shows a positive correlation with all analyzed elements and the parameters DQI (Dickson Quality Index), SA (Surface Area), RV (Root Volume), and mass. Conclusions: Results confirm the hypothesis that applying a mixture of fast-acting (YMC) and slow-acting (OES) fertilizer positively affects the nutrition and accumulation of macronutrients and the development of root systems in beech seedlings compared to fertilization with a single fertilizer. Full article

Novel recycled fertilizers could help close environmental nutrient cycles in the circular economy. To better understand their performance and residual value, commercially available biobased nitrogen (N) and phosphorus (P) fertilizers (BBFs) were tested in a two-year crop cycle of winter wheat and ryegrass. The N fertilizer replacement value of N-BBFs ranged from 47 to 80% in the main crop. Not all BBFs led to a similarly high N concentration as the mineral reference in the wheat straw. However, full and early fertilization with incorporation could make the fertilizing effect of N-BBFs more reliable. The P fertilizer replacement value ranged between 105 and 161% for the crop cycle. We assume that the N contained in biobased phosphorus fertilizers can be seen as unproblematic for losses during winter and can serve as a starter fertilizer already present in the soil for the succeeding crop in spring. In general, biobased P fertilizers had a higher residual value than biobased N fertilizers. However, these residual values were comparable to those of mineral fertilizer references. While P-BBFs proved to be a sustainable and reliable nutrient source for a crop cycle, the N-BBFs used as the main crop fertilizer were found to be more prone to environmental influences. Full article

This study explores the production of bio-nutrients from bioactive compound-rich spent coffee grounds (SCG) and biochar (BC) through composting after inoculation with a biological agent and its impact on the growth performance of garden cress and spinach. The SCG was composted with six doses of BC (0, 5, 10, 15, 20, and 25%). The compost with 10% BC exhibited the best maturity, humification, and phytotoxicity index values of dissolved organic carbon (DOC), humification index (E4/E6), and germination index (GI). A metagenome analysis showed that compost starter enhanced the bacterial community’s relative abundance, richness, and diversity in SCG and BC treatments. This improvement included increased Patescibacteria, which can break down noxious phenolic compounds found in SCG and BC. The BC enriched the compost with phosphorus and potassium while preserving the nitrogen. In plant growth experiments, the total chlorophyll content in compost-treated garden cress and spinach was 2.47 and 4.88 mg g⁻¹, respectively, which was significantly greater (p ≤ 0.05) than in unfertilized plants and similar to the plants treated with traditional fertilizer. Overall, the results show that the compost of SCG + BC was well-suited for promoting the growth of garden cress and spinach, providing adequate nutrients as a fertilizer for these leafy vegetables. Full article

Non-destructive, fast, and accurate prediction of soil organic matter content in farmland is of great significance for soil fertility assessment and rational fertilization. In the process of soil organic matter prediction, it is important to give full play to the advantages of different prediction models and to integrate different prediction models to innovatively construct a combined prediction model of soil organic matter content so as to improve the prediction accuracy and generalization ability of the model. In this study, the soil organic matter content of agricultural soils was taken as the research object, and the visible near-infrared hyperspectral curves of soils were measured by the Starter Kit indoor mobile scanning platform (Headwall Photonics, Bolton, MA, USA), and the original spectral curves were firstly de-noised by Savitzky–Golay (S-G) smoothing. Secondly, the smoothed and denoised spectral data were subjected to a first-order differential transform, and the features were selected based on the first-order differential transformed spectral data using the L1-paradigm algorithm features. Then, secondly, eight algorithms based on the selected feature bands, such as LASSO Regression (LASSO) (Model 1), Multilayer Perceptron (MLP) (Model 2), Random Forest (RF) (Model 3), Gaussian Kernel Regression (GKR) (Model 4), Ridge Regression (Model 5), Long Short-Term Memory (LSTM) (Model 6), Convolutional Neural Networks (CNN) (Model 7), and Support Vector Regression (SVR) (Model 8), were applied to construct a single-prediction model of soil organic matter content. Finally, a superior linear combination-prediction model was proposed by the eight single-prediction models constructed, and the standard deviation-based prediction validity was added to test the model. The results showed the following: (1) the weights of the eight single-prediction models in the combined prediction model were ${\omega }_1^{*}=0.099$, ${\omega }_2^{*}=0.202$, ${\omega }_3^{*}=0.000$, ${\omega }_4^{*}=0.357$, ${\omega }_5^{*}=0.088$, ${\omega }_6^{*}=0.089$, ${\omega }_7^{*}=0.000$, ${\omega }_8^{*}=0.165$, respectively; (2) The average precision E of the predicted values of soil organic matter content constructed based on the eight single-prediction models was 0.856; the average standard deviation σ was 0.181, and the average prediction validity M was 0.702; (3) The accuracy E of the predicted value of soil organic matter content of the combined model was 0.893, which was 4.322% higher than the average accuracy of the single model; the standard deviation of the combined model was 0.129, which was 28.333% lower than the average standard deviation of the single model, and the prediction validity M of the combined model was 0.778, which was 10.826% higher than the average prediction validity of the single model. The combined model can be used for the effective estimation of soil organic matter content in farmland with visible near-infrared spectral data, which can provide a basis and reference for the rapid detection of soil organic matter content in farmland. Full article

A prompt seed germination and emergence coupled with an excellent seedling vigor are highly desired features to ensure perfect crop establishment and subsequent vegetative growth. Seed dressing with pesticides represents the most common technology for enhancing seed performance after sowing, while little is known about biostimulant seed dressing. This practice could play a fundamental role in developing new sustainable starter fertilization for cereals. The enhancement of germination and seedling vigor of durum wheat seeds (Triticum turgidum L. subsp. durum (Desf.) Husn) was the main target of this research. The experiment took place in a germination cabinet under controlled environmental conditions, settled at the constant temperature of 10 °C and under dark conditions for 8 days. The different seed dressings, sprayed on the seeds, were composed by a combination of a fungicide and different biostimulants. Coleoptile and root length, as well as biomass, were significantly increased by the different biostimulants, compared to the control. As for germination traits, seeds treated with Codium fragile and Opuntia ficus-indica extracts, containing phytohormones and different nutrients, showed a final germination (96%) significantly higher than the one obtained with the control treatment (86%). These results show that treating seeds with a suitable dressing solution can greatly improve the germination features and seedling vigor of durum wheat. This can help the crop to withstand future stresses, especially in early stages, and possibly increase the grain yield with a reduction in agrochemicals. However, the combination of the substances used in the present study rarely showed a synergistic effect on the tested variable. Full article

Phosphorous (P) starter fertilization can increase maize (Zea mays L.) yield. Widespread application in soils with sufficient P availability leads to environmental risks. Subsequently, alternative strategies to support the maize plant’s early development are needed to lower P surpluses. Here, we conducted field experiments comparing standard starter fertilizer diammonium phosphate (DAP) (20.1 kg P ha⁻¹) to microgranular fertilizer (MG) (2.4 kg P ha⁻¹) and combined in-furrow inoculation with Bacillus atrophaeus and mycorrhizal fungi (Rhizoglomus irregulare, Funneliformis mosseae, and Funneliformis caledonium), alone and in combination. The soil microbial community inside and between the maize rows was monitored by quantitative PCR (qPCR)-based quantification of eight fungal and bacterial groups. The yield did not vary between fertilization with DAP or MG and no fertilizer control. The combined microorganism inoculum (MO), however, enhanced the yield by 4.2%. The soil microbial community composition was not affected by the MO application. However, on one field site and inside the rows, it leads to a significant increase in overall microbial gene copy numbers by 9.3% and a significant decrease in the relative abundance of the bacterial phylum of Bacillota (Firmicutes) by 18%. The in-furrow MO application is thus a promising option for starter fertilizer replacement. Full article

The rising shortage of fertilizer resources in crop-producing regions worldwide and the need for fertilizer use optimization to minimize the impact of salt injuries and ammonia toxicity are at the centre of a brewing storm call for sustainable fertilizer savings. The allocation of fertilizers will be an ever-increasing pressure source because of vast agricultural demands under changing climatic conditions. Therefore, starter fertilizers must complement their efficiency and aim to boost productivity and improve food quality to reduce its toxicities, and these observations are corroborated by an analysis of past and ongoing short-, medium-, and long-term experiments. Concurrently, to counterbalance nutrient uptake, fertilizing products containing select nutrients are commonly placed through soil–seed or soil–fertilizer–seed systems to enhance crop production and productivity. Knowledge of the importance of starter fertilizers and their implications as influenced by frequent environmental conditions and management practices remains essential for sustainable and socio-economics of human livelihoods and successful global agronomic food systems under climate change. Therefore, this review takes a closer look at the detailed starter fertilizers’ (N, P, and K) placement approaches exploring their implications on crop production cycles and integrating them with environmental and agronomic management practices that could help to tailor the appropriate fertilizer recommendations and minimise fertilizer toxicity. We explored the mechanisms by which fertilizer salt injury and ammonia toxicity interfere with the morpho-physiological and biochemical processes in most agronomic seed crops. Beyond this, we show the advances that have already been made, as well as suggestions and recommendations concerning managing fertilizer salt injuries and ammonia toxicity potentials in the agricultural industry. Full article

To diversify upland cropping systems, Italian ryegrass (Lolium multiflorum; IRG) can be incorporated as forage or green manure to soybean (Glycine max L.). The current study was conducted to analyze the effect of IRG cultivar and usage methods on the subsequent soybean above- and below-ground growth, as well as the yield, under different conditions. Three cycles of crop rotation were implemented with the combination of IRG cultivar (early maturing “Kowinearly”; late maturing “Winterhawk”), IRG usage (green manure for which both above- and below-ground biomass was incorporated, +CC; and forage for which only below-ground biomass was incorporated, −CC), and fallow soil as control. The soybean yield of +CC was consistently high regardless of the IRG cultivar, and it demonstrated an increase even under unfavorable weather conditions, while −CC treated did not differ from control. Incorporated IRG could serve as a starter fertilizer (79 to 156 kg ha⁻¹ of N input). Soybean root characteristic differences showed substantial variability depending on the year and treatments. However, when compared to the control, no adverse effects of IRG were evident. Thus, using IRG as a green manure has the potential to enhance soybean yield, while using IRG as a forage could bring additional harvested matter to the rotational system. Full article

Chickpea is a drought-tolerant crop and an important source of protein, relevant to its beneficial effects. The aim of this study was to assess the response to agronomic management, including water and nitrogen supply, of crop physiological and agronomic traits in relation to water use efficiency and grain protein composition. Two varieties, Pascià and Sultano, were grown at two different sites in South Italy under rainfed and irrigated conditions, with and without starter nitrogen fertilization. Crop physiological assessment was carried out by hyperspectral phenotyping at flowering and during grain filling. Increases in grain yield and grain size in relation to water supply were observed for water use up to about 400 mm. Water use efficiency increased under starter nitrogen fertilization, and Pascià showed the highest values (4.8 kg mm⁻¹). The highest correlations of the vegetation indexes with the agronomic traits were observed in the later growth stage, especially for the optimized soil-adjusted vegetation index (OSAVI); furthermore, grain filling rate showed a strong relationship with photochemical reflectance index (PRI). Experimental factors mainly influenced protein composition rather than protein content. In particular, the 7s vicilin protein fraction showed a negative correlation with grain yield and water use, while lectin showed an opposite response. Both fractions are of interest for consumer’s health because of their allergenic and antinutritional properties, respectively. Data from spectral phenotyping will be useful for digital farming applications, in order to assess crop physiological status in modern agricultural systems. Full article

UAN is a popular nitrogen fertilizer, broadly used in world agriculture. Research concerning the effects of this fertilizer is just as common. Contrarily, studies on the combined application of UAN with P, Mg or S are lacking. This fact has stimulated our study, undertaken in order to evaluate the effects of maize grown for grain and fertilized with UAN enriched with the macronutrients (P, Mg and S) on the crop’s yields and nitrogen metabolism. The following nitrogen fertilizers were applied: UAN 32%N, UAN + S—26% N + 3% S, UAN + P (Medium)—26% N and 11% P₂O₅, UAN + P (Starter)—21% N and 18% P₂O₅, UAN + Mg—20% N + 4% Mg. Based on the results of chemical analyses and yields of maize, the following indicators of nitrogen use efficiency (NUE) were calculated: agricultural efficiency (AE), physiological efficiency (PE), internal N utilization efficiency (IE), reciprocal internal N utilization efficiency (RIE), grain share in N accumulation (HI_N), recovery of N from mineral fertilizers (R_N) and partial nitrogen balance (PNB). The highest grain yields were harvested after the application of UAN + S/UAN + Mg, and after the pre-sowing and top-dressing application of UAN or UAN + P (Medium). Values of all calculated nitrogen use efficiency indicators were more strongly dependent on the weather conditions, which determined volumes of maize yields in a given year, than on the applied fertilization. Full article

Increasing the efficiency of nitrogen use (NUE) from mineral fertilizers is one of the most important priorities of modern agriculture. The objectives of the present study were to assess the role of different nitrogen (N), phosphorus (P) and sulfur (S) rates on maize grain yield (GY), crop residue biomass, NUE indices, N concentration in plants during the growing season, N management indices and to select the most suitable set of NUE indicators. The following factors were tested: band application of di-ammonium phosphate and ammonium sulphate mixture (NPS fertilizer at rates 0, 8.7, 17.4, 26.2 kg ha⁻¹ of P) and different total N rates (0, 60, 120, 180 kg ha⁻¹ of N). In each year of the study, a clear trend of increased GY after NP(S) band application was observed. A particularly positive influence of that factor was confirmed at the lowest level of N fertilization. On average, the highest GY values were obtained for N2P3 and N3P1 treatments. The total N uptake and NUE indices also increased after the band application. In addition, a trend of improved N remobilization efficiency and the N contribution of remobilized N to grain as a result of band application of NP(S) was observed. Among various NUE indices, internal N utilization efficiency (IE) exhibited the strongest, yet negative, correlation with GY, whereas IE was a function of the N harvest index. Full article

Slugs, primarily the gray garden slug, Deroceras reticulatum (Müller), are the most damaging non-arthropod pest of corn grown in conservation tillage systems in the US. These mollusks favor decaying plant residue on the soil surface, which provides food, shelter and optimum microenvironmental conditions for their development and survival. Here, field plot experiments evaluated several cultural and chemical control practices to suppress slug activity and feeding injury during early seedling growth. The use of row cleaners to remove surface residue over the seed row and starter fertilizer applied different ways during planting significantly reduced the percentage and severity of plants damaged by slugs by negatively affecting their activity around emerging seedlings and providing more favorable conditions for plants to outgrow and tolerate feeding injury. As rescue treatments, reduced rates of a 4% molluscicide bait applied as a directed band over the seed row, and broadcasted solutions of urea-based nitrogen applied under calm winds at night provided effective slug control. Practical considerations of these treatments are discussed, as well as changes in weather patterns and current planting practices that have had contrasting effects on slug populations and their potential damage. Full article

Under the high temporal variability of the Mediterranean climate, the prompt emergence of wheat seedlings and early vigor are pivotal attributes, positively affecting the final grain yield. Phosphorus (P) fertilization at sowing is largely used in wheat cultivation to support the early-season growth and promote a more rapid crop establishment. While conventional farming can rely on a wide variety of synthetic fertilizers, the number of options available for the starter fertilization of organic wheat is restricted and many are often unsuitable. Nanotechnology applied to fertilizers could provide a valuable means to combat this issue. This study aimed to evaluate the starter effect of a granular soil bio-enhancer (SBE) on bread wheat grown in two locations of Northern Tunisia as compared to conventional fertilization with diammonium phosphate (DAP). The SBE was obtained by physically grinding phosphate rocks at a nanoscale level and further mixing it with azotobacters. Aerial dry biomass, plant height, crop density, tiller density, leaf area index (LAI), and leaf P concentration were determined up to 70 days after emergence (DAE) to assess the early vigor of wheat seedlings. The application of SBE before sowing resulted in a greater early vigor of wheat seedlings as compared to commercial DAP over three consecutive growing seasons. Specifically, the aerial dry biomass and the plant height at 7 DAE were found to have increased by 56% and 48%, respectively. LAI at 70 DAE was enhanced by 8.5%, while moderate percentage increases were detected for both crop and tiller density. Finally, wheat plants fertilized with SBE showed a significantly higher leaf P concentration than DAP-fertilized plants in 2020 and 2021 (+21% and +32%, respectively). Full article

Intercropping maize and forage cowpea is a widely proposed strategy to improve land use efficiency, and maximize the economic value of the farming system, especially in developing countries with restricted resources. The current study was carried out during the successive summers of 2020 and 2021 in Northern Egypt. The main objective was to evaluate the effect of three N schedules (NS1, NS2, NS3), when three different maize–cowpea intercropping patterns (IP1, IP2, IP3) were applied, on the grain yield of maize, forage yield and quality of forage cowpea. In addition, yield gain and land use efficiency were evaluated using the land equivalent ratio (LER) and dry matter equivalent ratio (DMER) indices. Results revealed that the intercropping patterns that provided wider spacings for the component crops and reduced the competition between them, mainly IP3, resulted in the best performances for the two crops. This was clear for maize ear and grain yields, 100-grain weight and harvest index, in addition to cowpea fresh and dry forage yields, crude protein and non-fiber carbohydrates of the three cuts. Regarding the applied N schedules, NS1 which included the application of a N starter dose with sowing proved to be the most efficient schedule that led to the best performance for both crops. Maize produced 9.07 t ha⁻¹ grain yield under IP3 and NS1. In addition, the application of IP3 resulted in the highest significant cowpea dry forage yield (DFY), with the highest crude protein (CP) content. The DFY of cuts 1, 2, and 3 amounted to 1.27, 0.45, and 0.24 t ha⁻¹, while the CP content for the three respective cuts reached 159.49, 157.96, and 148.91 g kg⁻¹. Nonetheless, NS1 produced a reasonable amount of DFY with high CP content. It is recommended to follow the third proposed intercropping pattern (IP3) and to include a nitrogen starter dose (NS1) in the fertilization scheme to ensure highest productivity from the intercropped maize and forage cowpea. Full article